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* port forwarding form IP range
@ 2006-03-11 12:24 Nilesh
  2006-03-11 12:40 ` Leandro Silva
  0 siblings, 1 reply; 16+ messages in thread
From: Nilesh @ 2006-03-11 12:24 UTC (permalink / raw)
  To: iptables; +Cc: iptables

[-- Attachment #1: Type: text/plain, Size: 1105 bytes --]

Dear all,

I have two squid proxy servers and two ISP 

1)	192.168.0.1 port 3128
2)	192.168.0.3 port 3128

We have around 70 comps assigned IP’s between
192.168.0.4 to 192.168.0.250
The default proxy we are using is 192.168.0.1 which is
on the ISP 1.
Now I have configured 192.168.0.3 squid proxy server
on ISP 2 line.
Both ISP 1 and ISP 2 are landing (connected) on the
same Switch.

Now I want setup the request coming from IP range
(192.168.0.10 to 192.168.0.20) for the 
192.168.0.1:3128 
Will be forward to 192.168.0.3:3128
So the users from this IP range will access only
192.168.0.3 proxy server.

Could any one please help me which rules should I use
in IPTABLES .

I have attached herewith my rc.firewall file.

Please help me.

Regards
Nilesh.

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[-- Attachment #2: 543152633-rc.firewall --]
[-- Type: application/octet-stream, Size: 19600 bytes --]

#!/bin/sh
#
# rc.firewall-2.4-stronger
#
FWVER=0.80s

#          An example of a stronger IPTABLES firewall with IP Masquerade 
#          support for 2.4.x kernels.  
#
# Log:
#
#   0.80s - Added a DISABLED ip_nat_irc kernel module section, changed the
#           default of the ip_conntrack_irc to NOT load by default, and 
#           added additional kernel module comments
#   0.79s - ruleset now uses modprobe instead of insmod
#   0.78s - REJECT is not a legal policy yet; back to DROP
#   0.77s - Changed the default block behavior to REJECT not DROP
#   0.76s - Added a comment about the OPTIONAL WWW ruleset and a comment
#           where to put optional PORTFW commands
#   0.75s - Added clarification that PPPoE users need to use
#           "ppp0" instead of "eth0" for their external interface
#   0.74s - Changed the EXTIP command to work on NON-English distros
#   0.73s - Added comments in the output section that DHCPd is optional
#           and changed the default settings to disabled
#   0.72s - Changed the filter from the INTNET to the INTIP to be
#           stateful; moved the command VARs to the top and made the
#           rest of the script to use them
#   0.70s - Added a disabled examples for allowing internal DHCP  
#           and external WWW access to the server
#   0.63s - Added support for the IRC module
#   0.62s - Initial version based upon the basic 2.4.x rc.firewall


echo -e "\nLoading STRONGER rc.firewall - version $FWVER..\n"


# The location of various iptables and other shell programs
#
#   If your Linux distribution came with a copy of iptables, most
#   likely it is located in /sbin.  If you manually compiled 
#   iptables, the default location is in /usr/local/sbin
#
# ** Please use the "whereis iptables" command to figure out 
# ** where your copy is and change the path below to reflect 
# ** your setup
#
IPTABLES=/sbin/iptables
#IPTABLES=/usr/local/sbin/iptables
#
LSMOD=/sbin/lsmod
DEPMOD=/sbin/depmod
MODPROBE=/sbin/modprobe
GREP=/bin/grep
AWK=/bin/awk
SED=/bin/sed
IFCONFIG=/sbin/ifconfig


#Setting the EXTERNAL and INTERNAL interfaces for the network
#
#  Each IP Masquerade network needs to have at least one
#  external and one internal network.  The external network
#  is where the natting will occur and the internal network
#  should preferably be addressed with a RFC1918 private address
#  scheme.
#
#  For this example, "eth0" is external and "eth1" is internal"
#
#  NOTE:  If this doesnt EXACTLY fit your configuration, you must 
#         change the EXTIF or INTIF variables above. For example: 
#
#            If you are a PPPoE or analog modem user:
#
#               EXTIF="ppp0" 
#
EXTIF="ppp0"
INTIF="eth1"
echo "  External Interface:  $EXTIF"
echo "  Internal Interface:  $INTIF"
echo "  ---"

# Specify your Static IP address here or let the script take care of it 
# for you.
#
#   If you prefer to use STATIC addresses in your firewalls, un-# out the
#   static example below and # out the dynamic line.  If you don't care,
#   just leave this section alone.
#
#   If you have a DYNAMIC IP address, the ruleset already takes care of
#   this for you.  Please note that the different single and double quote 
#   characters and the script MATTER.
#
#
#   DHCP users:
#   -----------
#   If you get your TCP/IP address via DHCP, **you will need ** to enable the 
#   #ed out command below underneath the PPP section AND replace the word 
#   "eth0" with the name of your EXTERNAL Internet connection (ppp0, ippp0, 
#   etc) on the lines for "ppp-ip" and "extip".  You should also note that the 
#   DHCP server can and will change IP addresses on you.  To deal with this, 
#   users should configure their DHCP client to re-run the rc.firewall ruleset 
#   everytime the DHCP lease is renewed.
#
#     NOTE #1:  Some DHCP clients like the original "pump" (the newer
#               versions have been fixed) did NOT have the ability to run 
#               scripts after a lease-renew.  Because of this, you need to 
#               replace it with something like "dhcpcd" or "dhclient".
#
#     NOTE #2:  The syntax for "dhcpcd" has changed in recent versions.
#
#               Older versions used syntax like:
#                         dhcpcd -c /etc/rc.d/rc.firewall eth0
#
#               Newer versions execute a file called /etc/dhcpc/dhcpcd-eth0.exe
#
#     NOTE #3:  For Pump users, put the following line in /etc/pump.conf:
#
#                   script /etc/rc.d/rc.firewall
#
#   PPP users:
#   ----------
#   If you aren't already aware, the /etc/ppp/ip-up script is always run when 
#   a PPP connection comes up.  Because of this, we can make the ruleset go and 
#   get the new PPP IP address and update the strong firewall ruleset.
#
#   If the /etc/ppp/ip-up file already exists, you should edit it and add a line
#   containing "/etc/rc.d/rc.firewall" near the end of the file.
#
#   If you don't already have a /etc/ppp/ip-up sccript, you need to create the 
#   following link to run the /etc/rc.d/rc.firewall script.
#
#       ln -s /etc/rc.d/rc.firewall /etc/ppp/ip-up
#
#   * You then want to enable the #ed out shell command below *
#
#
# Determine the external IP automatically:
# ----------------------------------------
#
#  The following line will determine your external IP address.  This
#  line is somewhat complex and confusing but it will also work for
#  all NON-English Linux distributions:
#
EXTIP="`$IFCONFIG $EXTIF | $AWK \
 /$EXTIF/'{next}//{split($0,a,":");split(a[2],a," ");print a[1];exit}'`"


# For users who wish to use STATIC IP addresses:
#
#  # out the EXTIP line above and un-# out the EXTIP line below
#
#EXTIP="your.static.PPP.address"
#EXTIP="203.129.224.149"
echo "  External IP: $EXTIP"
echo "  ---"


# Assign the internal TCP/IP network and IP address
INTNET="192.168.0.0/24"
INTIP="192.168.0.1/24"
echo "  Internal Network: $INTNET"
echo "  Internal IP:      $INTIP"
echo "  ---"




# Setting a few other local variables
#
UNIVERSE="0.0.0.0/0"

#======================================================================
#== No editing beyond this line is required for initial MASQ testing ==

# Need to verify that all modules have all required dependencies
#
echo "  - Verifying that all kernel modules are ok"
$DEPMOD -a

echo -en "    Loading kernel modules: "

# With the new IPTABLES code, the core MASQ functionality is now either
# modular or compiled into the kernel.  This HOWTO shows ALL IPTABLES
# options as MODULES.  If your kernel is compiled correctly, there is
# NO need to load the kernel modules manually.  
#
#  NOTE: The following items are listed ONLY for informational reasons.
#        There is no reason to manual load these modules unless your
#        kernel is either mis-configured or you intentionally disabled
#        the kernel module autoloader.
#

# Upon the commands of starting up IP Masq on the server, the
# following kernel modules will be automatically loaded:
#
# NOTE:  Only load the IP MASQ modules you need.  All current IP MASQ 
#        modules are shown below but are commented out from loading.
# ===============================================================

#Load the main body of the IPTABLES module - "ip_tables"
#  - Loaded automatically when the "iptables" command is invoked
#
#  - Loaded manually to clean up kernel auto-loading timing issues
#
echo -en "ip_tables, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_tables | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_tables
fi


#Load the IPTABLES filtering module - "iptable_filter" 
#
#  - Loaded automatically when filter policies are activated


#Load the stateful connection tracking framework - "ip_conntrack"
#
# The conntrack  module in itself does nothing without other specific 
# conntrack modules being loaded afterwards such as the "ip_conntrack_ftp"
# module
#
#  - This module is loaded automatically when MASQ functionality is 
#    enabled 
#
#  - Loaded manually to clean up kernel auto-loading timing issues
#
echo -en "ip_conntrack, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_conntrack | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_conntrack
fi


#Load the FTP tracking mechanism for full FTP tracking
#
# Enabled by default -- insert a "#" on the next line to deactivate
#
echo -e "ip_conntrack_ftp, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_conntrack_ftp | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_conntrack_ftp
fi


#Load the IRC tracking mechanism for full IRC tracking
#
# Disabled by default -- insert a "#" on the next few lines to activate
#
# echo -en "                             ip_conntrack_irc, "
#
#Verify the module isn't loaded.  If it is, skip it
#
# if [ -z "` $LSMOD | $GREP ip_conntrack_irc | $AWK {'print $1'} `" ]; then
#    $MODPROBE ip_conntrack_irc
# fi


#Load the general IPTABLES NAT code - "iptable_nat"
#  - Loaded automatically when MASQ functionality is turned on
# 
#  - Loaded manually to clean up kernel auto-loading timing issues
#
echo -en "iptable_nat, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP iptable_nat | $AWK {'print $1'} `" ]; then
   $MODPROBE iptable_nat
fi


#Loads the FTP NAT functionality into the core IPTABLES code
# Required to support non-PASV FTP.
#
# Enabled by default -- insert a "#" on the next line to deactivate
#
echo -e "ip_nat_ftp"
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_nat_ftp | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_nat_ftp
fi


#Loads the IRC NAT functionality (for DCC) into the core IPTABLES code
#
# DISABLED by default -- delete the "#" on the next few lines to activate
#
echo -e "ip_nat_irc"
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_nat_irc | $AWK {'print $1'} `" ]; then
    $MODPROBE ip_nat_irc
fi


echo "  ---"

# Just to be complete, here is a partial list of some of the other  
# IPTABLES kernel modules and their function.  Please note that most 
# of these modules (the ipt ones) are automatically loaded by the 
# master kernel module for proper operation and don't need to be 
# manually loaded.
# --------------------------------------------------------------------
#
#    ip_nat_snmp_basic - this module allows for proper NATing of some 
#                        SNMP traffic
#
#    iptable_mangle    - this target allows for packets to be 
#                        manipulated for things like the TCPMSS 
#                        option, etc.
#
# --
#
#    ipt_mark       - this target marks a given packet for future action.
#                     This automatically loads the ipt_MARK module
#
#    ipt_tcpmss     - this target allows to manipulate the TCP MSS
#                     option for braindead remote firewalls.
#                     This automatically loads the ipt_TCPMSS module
#
#    ipt_limit      - this target allows for packets to be limited to
#                     to many hits per sec/min/hr
#
#    ipt_multiport  - this match allows for targets within a range
#                     of port numbers vs. listing each port individually
#
#    ipt_state      - this match allows to catch packets with various
#                     IP and TCP flags set/unset
#
#    ipt_unclean    - this match allows to catch packets that have invalid
#                     IP/TCP flags set
#
#    iptable_filter - this module allows for packets to be DROPped, 
#                     REJECTed, or LOGged.  This module automatically 
#                     loads the following modules:
#
#                     ipt_LOG - this target allows for packets to be 
#                               logged
#
#                     ipt_REJECT - this target DROPs the packet and returns 
#                                  a configurable ICMP packet back to the 
#                                  sender.


#CRITICAL:  Enable IP forwarding since it is disabled by default since
#
#           Redhat Users:  you may try changing the options in
#                          /etc/sysconfig/network from:
#
#                       FORWARD_IPV4=false
#                             to
#                       FORWARD_IPV4=true
#
echo "  Enabling forwarding.."
echo "1" > /proc/sys/net/ipv4/ip_forward


# Dynamic IP users:
#
#   If you get your IP address dynamically from SLIP, PPP, or DHCP, 
#   enable the following option.  This enables dynamic-address hacking
#   which makes the life with Diald and similar programs much easier.
#
echo "  Enabling DynamicAddr.."
echo "1" > /proc/sys/net/ipv4/ip_dynaddr

echo "  ---"

#############################################################################
#
# Enable Stronger IP forwarding and Masquerading
#
#  NOTE:  In IPTABLES speak, IP Masquerading is a form of SourceNAT or SNAT.
#
#  NOTE #2:  The following is an example for an internal LAN address in the
#            192.168.1.x network with a 255.255.255.0 or a "24" bit subnet 
#            mask connecting to the Internet on external interface "eth0".  
#            This example will MASQ internal traffic out to the Internet 
#            but not allow non-initiated traffic into your internal network.
#
#            
#         ** Please change the above network numbers, subnet mask, and your 
#         *** Internet connection interface name to match your setup
#         

#Clearing any previous configuration
#
#  Unless specified, the defaults for INPUT, OUTPUT, and FORWARD to DROP
#
#    You CANNOT change this to REJECT as it isn't a vaild policy setting.
#    If you want REJECT, you must explictly REJECT at the end of a giving 
#    INPUT, OUTPUT, or FORWARD chain
#
echo "  Clearing any existing rules and setting default policy to DROP.."
$IPTABLES -P INPUT DROP
$IPTABLES -F INPUT 
$IPTABLES -P OUTPUT DROP
$IPTABLES -F OUTPUT 
$IPTABLES -P FORWARD DROP
$IPTABLES -F FORWARD 
$IPTABLES -F -t nat

#Not needed and it will only load the unneeded kernel module
$IPTABLES -F -t mangle
#
# Flush the user chain.. if it exists
if [ -n "`$IPTABLES -L | $GREP drop-and-log-it`" ]; then
   $IPTABLES -F drop-and-log-it
fi
#
# Delete all User-specified chains
$IPTABLES -X
#
# Reset all IPTABLES counters
$IPTABLES -Z


#Configuring specific CHAINS for later use in the ruleset
#
#  NOTE:  Some users prefer to have their firewall silently
#         "DROP" packets while others prefer to use "REJECT"
#         to send ICMP error messages back to the remote 
#         machine.  The default is "REJECT" but feel free to
#         change this below.
#
# NOTE: Without the --log-level set to "info", every single
#       firewall hit will goto ALL vtys.  This is a very big
#       pain.
#
echo "  Creating a DROP chain.."
$IPTABLES -N drop-and-log-it
$IPTABLES -A drop-and-log-it -j LOG --log-level info 
$IPTABLES -A drop-and-log-it -j REJECT

echo -e "\n   - Loading INPUT rulesets"


#######################################################################
# INPUT: Incoming traffic from various interfaces.  All rulesets are 
#        already flushed and set to a default policy of DROP. 
#

# loopback interfaces are valid.
#
$IPTABLES -A INPUT -i lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT


# local interface, local machines, going anywhere is valid
#
$IPTABLES -A INPUT -i $INTIF -s $INTNET -d $UNIVERSE -j ACCEPT

# remote interface, claiming to be local machines, IP spoofing, get lost
#
$IPTABLES -A INPUT -i $EXTIF -s $INTNET -d $UNIVERSE -j drop-and-log-it


# external interface, from any source, for ICMP traffic is valid
#
#  If you would like your machine to "ping" from the Internet, 
#  enable this next line
#
#$IPTABLES -A INPUT -i $EXTIF -p ICMP -s $UNIVERSE -d $EXTIP -j ACCEPT


# remote interface, any source, going to permanent PPP address is valid
#
$IPTABLES -A INPUT -i $EXTIF -s $UNIVERSE -d $EXTIP -j ACCEPT


# Allow any related traffic coming back to the MASQ server in
#
$IPTABLES -A INPUT -i $EXTIF -s $UNIVERSE -d $EXTIP -m state --state \
 ESTABLISHED,RELATED -j ACCEPT


# ----- Begin OPTIONAL INPUT Section -----
#

# DHCPd - Enable the following lines if you run an INTERNAL DHCPd server
#
#$IPTABLES -A INPUT -i $INTIF -p tcp --sport 68 --dport 67 -j ACCEPT
#$IPTABLES -A INPUT -i $INTIF -p udp --sport 68 --dport 67 -j ACCEPT

# HTTPd - Enable the following lines if you run an EXTERNAL WWW server
#
#    NOTE:  This is NOT needed for simply enabling PORTFW.  This is ONLY 
#           for users that plan on running Apache on the MASQ server itself
#
#echo -e "      - Allowing EXTERNAL access to the WWW server"
#$IPTABLES -A INPUT -i $EXTIF -m state --state NEW,ESTABLISHED,RELATED \
# -p tcp -s $UNIVERSE -d $EXTIP --dport 80 -j ACCEPT

#
# ----- End OPTIONAL INPUT Section -----



# Catch all rule, all other incoming is denied and logged. 
#
$IPTABLES -A INPUT -s $UNIVERSE -d $UNIVERSE -j drop-and-log-it


echo -e "   - Loading OUTPUT rulesets"

#######################################################################
# OUTPUT: Outgoing traffic from various interfaces.  All rulesets are 
#         already flushed and set to a default policy of DROP. 
#

# loopback interface is valid.
#
$IPTABLES -A OUTPUT -o lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT


# local interfaces, any source going to local net is valid
#
$IPTABLES -A OUTPUT -o $INTIF -s $EXTIP -d $INTNET -j ACCEPT


# local interface, any source going to local net is valid
#
$IPTABLES -A OUTPUT -o $INTIF -s $INTIP -d $INTNET -j ACCEPT


# outgoing to local net on remote interface, stuffed routing, deny
#
$IPTABLES -A OUTPUT -o $EXTIF -s $UNIVERSE -d $INTNET -j drop-and-log-it


# anything else outgoing on remote interface is valid
#
$IPTABLES -A OUTPUT -o $EXTIF -s $EXTIP -d $UNIVERSE -j ACCEPT


# ----- Begin OPTIONAL OUTPUT Section -----
#

# DHCPd - Enable the following lines if you run an INTERNAL DHCPd server
#         - Remove BOTH #s all the #s if you need this functionality.
#
#$IPTABLES -A OUTPUT -o $INTIF -p tcp -s $INTIP --sport 67 \
# -d 255.255.255.255 --dport 68 -j ACCEPT
#$IPTABLES -A OUTPUT -o $INTIF -p udp -s $INTIP --sport 67 \
# -d 255.255.255.255 --dport 68 -j ACCEPT

#
# ----- End OPTIONAL OUTPUT Section -----


# Catch all rule, all other outgoing is denied and logged. 
#
$IPTABLES -A OUTPUT -s $UNIVERSE -d $UNIVERSE -j drop-and-log-it


echo -e "   - Loading FORWARD rulesets"

#######################################################################
# FORWARD: Enable Forwarding and thus IPMASQ
#

#- ----- Begin OPTIONAL FORWARD Section -----
#
# ----- End OPTIONAL FORWARD Section -----


echo "     - FWD: Allow all connections OUT and only existing/related IN"
$IPTABLES -A FORWARD -i $EXTIF -o $INTIF -m state --state ESTABLISHED,RELATED \
 -j ACCEPT
$IPTABLES -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT

# Catch all rule, all other forwarding is denied and logged. 
#
$IPTABLES -A FORWARD -j drop-and-log-it


#echo "     - NAT: Enabling SNAT (MASQUERADE) functionality on $EXTIF"
#
#More liberal form
#$IPTABLES -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE
#
#Stricter form
#$IPTABLES -t nat -A PREROUTING -o $EXTIF -j SNAT --to $EXTIP
$IPTABLES -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-ports 192.168.0.1:3128
#$IPTABLES -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j DNAT --to 192.168.0.1:3128 -s ! 192.168.0.0/24
$IPTABLES -A OUTPUT -j ACCEPT -m state --state NEW -o eth0 -p tcp --dport 80
$IPTABLES -t nat -A POSTROUTING -o $EXTIF -j SNAT --to-source $EXTIP

#######################################################################
echo -e "\nStronger rc.firewall-2.4 $FWVER done.\n"

^ permalink raw reply	[flat|nested] 16+ messages in thread
* RE: port forwarding form IP range
@ 2006-03-13 11:37 Nilesh
  0 siblings, 0 replies; 16+ messages in thread
From: Nilesh @ 2006-03-13 11:37 UTC (permalink / raw)
  To: edvin.seferovic, netfilter

no there is only Forward default chain.
I am confused , I have attached herewith my
rc.firewall  could you please look into.If I am going
wrong way.

Thanks
Nilesh,

--- Seferovic Edvin <edvin.seferovic@kolp.at> wrote:

> -i eth1 -o eth1 ??? How is this suppose to work? Is
> there any forward chain
> on one interface?
> 
> iptables -A FORWARD -s 192.168.0.10 -i eth1 -d
> 192.168.0.1 -o eth1 -p tcp --sport 1024:65535
> --dport
> 3128 -j ACCEPT.
> 
> Regards,
> 
> Edvin
> 
> --- Rob Sterenborg <rob@sterenborg.info> wrote:
> 
> > On Mon, March 13, 2006 09:53, Nilesh wrote:
> > > Thanks Leandro,
> > >
> > > I have tried with this rules but unfortunately
> not
> > > working.
> > > Squid server running on the 192.168.0.3 and its
> > > working  fine. I have not installed any firewall
> > on
> > > the 192.168.0.3.
> > > In my Internet browser settings If I chnage the
> > > settings from 192.168.0.1:3128 to
> 192.168.0.3:3128
> > I
> > > can surf the web.
> > > but If I dont change to 192.168.0.3:3128 proxy
> > > settings I get the connection timout error.
> > >
> > > I think DNAT is not working
> > 
> > Probably you tell Netfilter to do DNAT, but are
> not
> > allowing it.
> > Do you have a FORWARD rule that allows this
> traffic
> > or is your policy ACCEPT ?
> > 
> > Please don't top-post.
> > 
> > 
> > Gr,
> > Rob
> > 
> > 
> > > --- Leandro Silva <lansoweb@gmail.com> wrote:
> > >
> > >> Hello !
> > >>
> > >> You can use something like that:
> > >>
> > >> iptables -I PREROUTING -t nat -s 192.168.0.10
> -p
> > tcp
> > >> --dport 80 -j
> > >> DNAT --to 192.168.0.3:3128
> > >> iptables -I PREROUTING -t nat -s 192.168.0.10
> -p
> > tcp
> > >> --dport 3128 -j
> > >> DNAT --to 192.168.0.3:3128
> > >>
> > >> If you have iprange compiled for iptables you
> can
> > >> use:
> > >>
> > >> iptables -I PREROUTING -t nat -m iprange
> > --src-range
> > >> 192.168.0.10-192.168.0.20 -p tcp --dport 80 -j
> > DNAT
> > >> --to
> > >> 192.168.0.3:3128
> > >> iptables -I PREROUTING -t nat -m iprange
> > --src-range
> > >> 192.168.0.10-192.168.0.20 -p tcp --dport 3128
> -j
> > >> DNAT --to
> > >> 192.168.0.3:3128
> > >>
> > >> I hope this can help,
> > >> Leandro
> > >>
> > >> 2006/3/11, Nilesh <niluforalways@yahoo.com>:
> > >> > Dear all,
> > >> >
> > >> > I have two squid proxy servers and two ISP
> > >> >
> > >> > 1)      192.168.0.1 port 3128
> > >> > 2)      192.168.0.3 port 3128
> > >> >
> > >> > We have around 70 comps assigned IP's between
> > >> > 192.168.0.4 to 192.168.0.250
> > >> > The default proxy we are using is 192.168.0.1
> > >> which is
> > >> > on the ISP 1.
> > >> > Now I have configured 192.168.0.3 squid proxy
> > >> server
> > >> > on ISP 2 line.
> > >> > Both ISP 1 and ISP 2 are landing (connected)
> on
> > >> the
> > >> > same Switch.
> > >> >
> > >> > Now I want setup the request coming from IP
> > range
> > >> > (192.168.0.10 to 192.168.0.20) for the
> > >> > 192.168.0.1:3128
> > >> > Will be forward to 192.168.0.3:3128
> > >> > So the users from this IP range will access
> > only
> > >> > 192.168.0.3 proxy server.
> > >> >
> > >> > Could any one please help me which rules
> should
> > I
> > >> use
> > >> > in IPTABLES .
> > >> >
> > >> > I have attached herewith my rc.firewall file.
> > >> >
> > >> > Please help me.
> > >> >
> > >> > Regards
> > >> > Nilesh.
> > 
> > 
> > 
> > 
> 
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> http://mail.yahoo.com 
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> http://mail.yahoo.com 
> 
> 
> 
> 


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam
protection around 
http://mail.yahoo.com 

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 


^ permalink raw reply	[flat|nested] 16+ messages in thread
* RE: port forwarding form IP range
@ 2006-03-13 11:39 Nilesh
  2006-03-13 12:04 ` Seferovic Edvin
  0 siblings, 1 reply; 16+ messages in thread
From: Nilesh @ 2006-03-13 11:39 UTC (permalink / raw)
  To: Nilesh, edvin.seferovic, netfilter

[-- Attachment #1: Type: text/plain, Size: 4609 bytes --]

Sorry earlier mail was without attchment.

--- Nilesh <niluforalways@yahoo.com> wrote:

> no there is only Forward default chain.
> I am confused , I have attached herewith my
> rc.firewall  could you please look into.If I am
> going
> wrong way.
> 
> Thanks
> Nilesh,
> 
> --- Seferovic Edvin <edvin.seferovic@kolp.at> wrote:
> 
> > -i eth1 -o eth1 ??? How is this suppose to work?
> Is
> > there any forward chain
> > on one interface?
> > 
> > iptables -A FORWARD -s 192.168.0.10 -i eth1 -d
> > 192.168.0.1 -o eth1 -p tcp --sport 1024:65535
> > --dport
> > 3128 -j ACCEPT.
> > 
> > Regards,
> > 
> > Edvin
> > 
> > --- Rob Sterenborg <rob@sterenborg.info> wrote:
> > 
> > > On Mon, March 13, 2006 09:53, Nilesh wrote:
> > > > Thanks Leandro,
> > > >
> > > > I have tried with this rules but unfortunately
> > not
> > > > working.
> > > > Squid server running on the 192.168.0.3 and
> its
> > > > working  fine. I have not installed any
> firewall
> > > on
> > > > the 192.168.0.3.
> > > > In my Internet browser settings If I chnage
> the
> > > > settings from 192.168.0.1:3128 to
> > 192.168.0.3:3128
> > > I
> > > > can surf the web.
> > > > but If I dont change to 192.168.0.3:3128 proxy
> > > > settings I get the connection timout error.
> > > >
> > > > I think DNAT is not working
> > > 
> > > Probably you tell Netfilter to do DNAT, but are
> > not
> > > allowing it.
> > > Do you have a FORWARD rule that allows this
> > traffic
> > > or is your policy ACCEPT ?
> > > 
> > > Please don't top-post.
> > > 
> > > 
> > > Gr,
> > > Rob
> > > 
> > > 
> > > > --- Leandro Silva <lansoweb@gmail.com> wrote:
> > > >
> > > >> Hello !
> > > >>
> > > >> You can use something like that:
> > > >>
> > > >> iptables -I PREROUTING -t nat -s 192.168.0.10
> > -p
> > > tcp
> > > >> --dport 80 -j
> > > >> DNAT --to 192.168.0.3:3128
> > > >> iptables -I PREROUTING -t nat -s 192.168.0.10
> > -p
> > > tcp
> > > >> --dport 3128 -j
> > > >> DNAT --to 192.168.0.3:3128
> > > >>
> > > >> If you have iprange compiled for iptables you
> > can
> > > >> use:
> > > >>
> > > >> iptables -I PREROUTING -t nat -m iprange
> > > --src-range
> > > >> 192.168.0.10-192.168.0.20 -p tcp --dport 80
> -j
> > > DNAT
> > > >> --to
> > > >> 192.168.0.3:3128
> > > >> iptables -I PREROUTING -t nat -m iprange
> > > --src-range
> > > >> 192.168.0.10-192.168.0.20 -p tcp --dport 3128
> > -j
> > > >> DNAT --to
> > > >> 192.168.0.3:3128
> > > >>
> > > >> I hope this can help,
> > > >> Leandro
> > > >>
> > > >> 2006/3/11, Nilesh <niluforalways@yahoo.com>:
> > > >> > Dear all,
> > > >> >
> > > >> > I have two squid proxy servers and two ISP
> > > >> >
> > > >> > 1)      192.168.0.1 port 3128
> > > >> > 2)      192.168.0.3 port 3128
> > > >> >
> > > >> > We have around 70 comps assigned IP's
> between
> > > >> > 192.168.0.4 to 192.168.0.250
> > > >> > The default proxy we are using is
> 192.168.0.1
> > > >> which is
> > > >> > on the ISP 1.
> > > >> > Now I have configured 192.168.0.3 squid
> proxy
> > > >> server
> > > >> > on ISP 2 line.
> > > >> > Both ISP 1 and ISP 2 are landing
> (connected)
> > on
> > > >> the
> > > >> > same Switch.
> > > >> >
> > > >> > Now I want setup the request coming from IP
> > > range
> > > >> > (192.168.0.10 to 192.168.0.20) for the
> > > >> > 192.168.0.1:3128
> > > >> > Will be forward to 192.168.0.3:3128
> > > >> > So the users from this IP range will access
> > > only
> > > >> > 192.168.0.3 proxy server.
> > > >> >
> > > >> > Could any one please help me which rules
> > should
> > > I
> > > >> use
> > > >> > in IPTABLES .
> > > >> >
> > > >> > I have attached herewith my rc.firewall
> file.
> > > >> >
> > > >> > Please help me.
> > > >> >
> > > >> > Regards
> > > >> > Nilesh.
> > > 
> > > 
> > > 
> > > 
> > 
> > 
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam?  Yahoo! Mail has the best spam
> > protection around 
> > http://mail.yahoo.com 
> > 
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam?  Yahoo! Mail has the best spam
> > protection around 
> > http://mail.yahoo.com 
> > 
> > 
> > 
> > 
> 
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> http://mail.yahoo.com 
> 
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam
> protection around 
> http://mail.yahoo.com 
> 

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

[-- Attachment #2: 543152633-rc.firewall --]
[-- Type: application/octet-stream, Size: 19913 bytes --]

#!/bin/sh
#
# rc.firewall-2.4-stronger
#
FWVER=0.80s

#          An example of a stronger IPTABLES firewall with IP Masquerade 
#          support for 2.4.x kernels.  
#
# Log:
#
#   0.80s - Added a DISABLED ip_nat_irc kernel module section, changed the
#           default of the ip_conntrack_irc to NOT load by default, and 
#           added additional kernel module comments
#   0.79s - ruleset now uses modprobe instead of insmod
#   0.78s - REJECT is not a legal policy yet; back to DROP
#   0.77s - Changed the default block behavior to REJECT not DROP
#   0.76s - Added a comment about the OPTIONAL WWW ruleset and a comment
#           where to put optional PORTFW commands
#   0.75s - Added clarification that PPPoE users need to use
#           "ppp0" instead of "eth0" for their external interface
#   0.74s - Changed the EXTIP command to work on NON-English distros
#   0.73s - Added comments in the output section that DHCPd is optional
#           and changed the default settings to disabled
#   0.72s - Changed the filter from the INTNET to the INTIP to be
#           stateful; moved the command VARs to the top and made the
#           rest of the script to use them
#   0.70s - Added a disabled examples for allowing internal DHCP  
#           and external WWW access to the server
#   0.63s - Added support for the IRC module
#   0.62s - Initial version based upon the basic 2.4.x rc.firewall


echo -e "\nLoading STRONGER rc.firewall - version $FWVER..\n"


# The location of various iptables and other shell programs
#
#   If your Linux distribution came with a copy of iptables, most
#   likely it is located in /sbin.  If you manually compiled 
#   iptables, the default location is in /usr/local/sbin
#
# ** Please use the "whereis iptables" command to figure out 
# ** where your copy is and change the path below to reflect 
# ** your setup
#
IPTABLES=/sbin/iptables
#IPTABLES=/usr/local/sbin/iptables
#
LSMOD=/sbin/lsmod
DEPMOD=/sbin/depmod
MODPROBE=/sbin/modprobe
GREP=/bin/grep
AWK=/bin/awk
SED=/bin/sed
IFCONFIG=/sbin/ifconfig


#Setting the EXTERNAL and INTERNAL interfaces for the network
#
#  Each IP Masquerade network needs to have at least one
#  external and one internal network.  The external network
#  is where the natting will occur and the internal network
#  should preferably be addressed with a RFC1918 private address
#  scheme.
#
#  For this example, "eth0" is external and "eth1" is internal"
#
#  NOTE:  If this doesnt EXACTLY fit your configuration, you must 
#         change the EXTIF or INTIF variables above. For example: 
#
#            If you are a PPPoE or analog modem user:
#
#               EXTIF="ppp0" 
#
EXTIF="ppp0"
INTIF="eth1"
echo "  External Interface:  $EXTIF"
echo "  Internal Interface:  $INTIF"
echo "  ---"

# Specify your Static IP address here or let the script take care of it 
# for you.
#
#   If you prefer to use STATIC addresses in your firewalls, un-# out the
#   static example below and # out the dynamic line.  If you don't care,
#   just leave this section alone.
#
#   If you have a DYNAMIC IP address, the ruleset already takes care of
#   this for you.  Please note that the different single and double quote 
#   characters and the script MATTER.
#
#
#   DHCP users:
#   -----------
#   If you get your TCP/IP address via DHCP, **you will need ** to enable the 
#   #ed out command below underneath the PPP section AND replace the word 
#   "eth0" with the name of your EXTERNAL Internet connection (ppp0, ippp0, 
#   etc) on the lines for "ppp-ip" and "extip".  You should also note that the 
#   DHCP server can and will change IP addresses on you.  To deal with this, 
#   users should configure their DHCP client to re-run the rc.firewall ruleset 
#   everytime the DHCP lease is renewed.
#
#     NOTE #1:  Some DHCP clients like the original "pump" (the newer
#               versions have been fixed) did NOT have the ability to run 
#               scripts after a lease-renew.  Because of this, you need to 
#               replace it with something like "dhcpcd" or "dhclient".
#
#     NOTE #2:  The syntax for "dhcpcd" has changed in recent versions.
#
#               Older versions used syntax like:
#                         dhcpcd -c /etc/rc.d/rc.firewall eth0
#
#               Newer versions execute a file called /etc/dhcpc/dhcpcd-eth0.exe
#
#     NOTE #3:  For Pump users, put the following line in /etc/pump.conf:
#
#                   script /etc/rc.d/rc.firewall
#
#   PPP users:
#   ----------
#   If you aren't already aware, the /etc/ppp/ip-up script is always run when 
#   a PPP connection comes up.  Because of this, we can make the ruleset go and 
#   get the new PPP IP address and update the strong firewall ruleset.
#
#   If the /etc/ppp/ip-up file already exists, you should edit it and add a line
#   containing "/etc/rc.d/rc.firewall" near the end of the file.
#
#   If you don't already have a /etc/ppp/ip-up sccript, you need to create the 
#   following link to run the /etc/rc.d/rc.firewall script.
#
#       ln -s /etc/rc.d/rc.firewall /etc/ppp/ip-up
#
#   * You then want to enable the #ed out shell command below *
#
#
# Determine the external IP automatically:
# ----------------------------------------
#
#  The following line will determine your external IP address.  This
#  line is somewhat complex and confusing but it will also work for
#  all NON-English Linux distributions:
#
EXTIP="`$IFCONFIG $EXTIF | $AWK \
 /$EXTIF/'{next}//{split($0,a,":");split(a[2],a," ");print a[1];exit}'`"


# For users who wish to use STATIC IP addresses:
#
#  # out the EXTIP line above and un-# out the EXTIP line below
#
#EXTIP="your.static.PPP.address"
#EXTIP="203.129.224.149"
echo "  External IP: $EXTIP"
echo "  ---"


# Assign the internal TCP/IP network and IP address
INTNET="192.168.0.0/24"
INTIP="192.168.0.1/24"
echo "  Internal Network: $INTNET"
echo "  Internal IP:      $INTIP"
echo "  ---"




# Setting a few other local variables
#
UNIVERSE="0.0.0.0/0"

#======================================================================
#== No editing beyond this line is required for initial MASQ testing ==

# Need to verify that all modules have all required dependencies
#
echo "  - Verifying that all kernel modules are ok"
$DEPMOD -a

echo -en "    Loading kernel modules: "

# With the new IPTABLES code, the core MASQ functionality is now either
# modular or compiled into the kernel.  This HOWTO shows ALL IPTABLES
# options as MODULES.  If your kernel is compiled correctly, there is
# NO need to load the kernel modules manually.  
#
#  NOTE: The following items are listed ONLY for informational reasons.
#        There is no reason to manual load these modules unless your
#        kernel is either mis-configured or you intentionally disabled
#        the kernel module autoloader.
#

# Upon the commands of starting up IP Masq on the server, the
# following kernel modules will be automatically loaded:
#
# NOTE:  Only load the IP MASQ modules you need.  All current IP MASQ 
#        modules are shown below but are commented out from loading.
# ===============================================================

#Load the main body of the IPTABLES module - "ip_tables"
#  - Loaded automatically when the "iptables" command is invoked
#
#  - Loaded manually to clean up kernel auto-loading timing issues
#
echo -en "ip_tables, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_tables | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_tables
fi


#Load the IPTABLES filtering module - "iptable_filter" 
#
#  - Loaded automatically when filter policies are activated


#Load the stateful connection tracking framework - "ip_conntrack"
#
# The conntrack  module in itself does nothing without other specific 
# conntrack modules being loaded afterwards such as the "ip_conntrack_ftp"
# module
#
#  - This module is loaded automatically when MASQ functionality is 
#    enabled 
#
#  - Loaded manually to clean up kernel auto-loading timing issues
#
echo -en "ip_conntrack, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_conntrack | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_conntrack
fi


#Load the FTP tracking mechanism for full FTP tracking
#
# Enabled by default -- insert a "#" on the next line to deactivate
#
echo -e "ip_conntrack_ftp, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_conntrack_ftp | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_conntrack_ftp
fi


#Load the IRC tracking mechanism for full IRC tracking
#
# Disabled by default -- insert a "#" on the next few lines to activate
#
# echo -en "                             ip_conntrack_irc, "
#
#Verify the module isn't loaded.  If it is, skip it
#
# if [ -z "` $LSMOD | $GREP ip_conntrack_irc | $AWK {'print $1'} `" ]; then
#    $MODPROBE ip_conntrack_irc
# fi


#Load the general IPTABLES NAT code - "iptable_nat"
#  - Loaded automatically when MASQ functionality is turned on
# 
#  - Loaded manually to clean up kernel auto-loading timing issues
#
echo -en "iptable_nat, "
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP iptable_nat | $AWK {'print $1'} `" ]; then
   $MODPROBE iptable_nat
fi


#Loads the FTP NAT functionality into the core IPTABLES code
# Required to support non-PASV FTP.
#
# Enabled by default -- insert a "#" on the next line to deactivate
#
echo -e "ip_nat_ftp"
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_nat_ftp | $AWK {'print $1'} `" ]; then
   $MODPROBE ip_nat_ftp
fi


#Loads the IRC NAT functionality (for DCC) into the core IPTABLES code
#
# DISABLED by default -- delete the "#" on the next few lines to activate
#
echo -e "ip_nat_irc"
#
#Verify the module isn't loaded.  If it is, skip it
#
if [ -z "` $LSMOD | $GREP ip_nat_irc | $AWK {'print $1'} `" ]; then
    $MODPROBE ip_nat_irc
fi


echo "  ---"

# Just to be complete, here is a partial list of some of the other  
# IPTABLES kernel modules and their function.  Please note that most 
# of these modules (the ipt ones) are automatically loaded by the 
# master kernel module for proper operation and don't need to be 
# manually loaded.
# --------------------------------------------------------------------
#
#    ip_nat_snmp_basic - this module allows for proper NATing of some 
#                        SNMP traffic
#
#    iptable_mangle    - this target allows for packets to be 
#                        manipulated for things like the TCPMSS 
#                        option, etc.
#
# --
#
#    ipt_mark       - this target marks a given packet for future action.
#                     This automatically loads the ipt_MARK module
#
#    ipt_tcpmss     - this target allows to manipulate the TCP MSS
#                     option for braindead remote firewalls.
#                     This automatically loads the ipt_TCPMSS module
#
#    ipt_limit      - this target allows for packets to be limited to
#                     to many hits per sec/min/hr
#
#    ipt_multiport  - this match allows for targets within a range
#                     of port numbers vs. listing each port individually
#
#    ipt_state      - this match allows to catch packets with various
#                     IP and TCP flags set/unset
#
#    ipt_unclean    - this match allows to catch packets that have invalid
#                     IP/TCP flags set
#
#    iptable_filter - this module allows for packets to be DROPped, 
#                     REJECTed, or LOGged.  This module automatically 
#                     loads the following modules:
#
#                     ipt_LOG - this target allows for packets to be 
#                               logged
#
#                     ipt_REJECT - this target DROPs the packet and returns 
#                                  a configurable ICMP packet back to the 
#                                  sender.


#CRITICAL:  Enable IP forwarding since it is disabled by default since
#
#           Redhat Users:  you may try changing the options in
#                          /etc/sysconfig/network from:
#
#                       FORWARD_IPV4=false
#                             to
#                       FORWARD_IPV4=true
#
echo "  Enabling forwarding.."
echo "1" > /proc/sys/net/ipv4/ip_forward


# Dynamic IP users:
#
#   If you get your IP address dynamically from SLIP, PPP, or DHCP, 
#   enable the following option.  This enables dynamic-address hacking
#   which makes the life with Diald and similar programs much easier.
#
echo "  Enabling DynamicAddr.."
echo "1" > /proc/sys/net/ipv4/ip_dynaddr

echo "  ---"

#############################################################################
#
# Enable Stronger IP forwarding and Masquerading
#
#  NOTE:  In IPTABLES speak, IP Masquerading is a form of SourceNAT or SNAT.
#
#  NOTE #2:  The following is an example for an internal LAN address in the
#            192.168.1.x network with a 255.255.255.0 or a "24" bit subnet 
#            mask connecting to the Internet on external interface "eth0".  
#            This example will MASQ internal traffic out to the Internet 
#            but not allow non-initiated traffic into your internal network.
#
#            
#         ** Please change the above network numbers, subnet mask, and your 
#         *** Internet connection interface name to match your setup
#         

#Clearing any previous configuration
#
#  Unless specified, the defaults for INPUT, OUTPUT, and FORWARD to DROP
#
#    You CANNOT change this to REJECT as it isn't a vaild policy setting.
#    If you want REJECT, you must explictly REJECT at the end of a giving 
#    INPUT, OUTPUT, or FORWARD chain
#
echo "  Clearing any existing rules and setting default policy to DROP.."
$IPTABLES -P INPUT DROP
$IPTABLES -F INPUT 
$IPTABLES -P OUTPUT DROP
$IPTABLES -F OUTPUT 
$IPTABLES -P FORWARD ACCEPT
$IPTABLES -F FORWARD 
$IPTABLES -F -t nat

#Not needed and it will only load the unneeded kernel module
$IPTABLES -F -t mangle
#
# Flush the user chain.. if it exists
if [ -n "`$IPTABLES -L | $GREP drop-and-log-it`" ]; then
   $IPTABLES -F drop-and-log-it
fi
#
# Delete all User-specified chains
$IPTABLES -X
#
# Reset all IPTABLES counters
$IPTABLES -Z


#Configuring specific CHAINS for later use in the ruleset
#
#  NOTE:  Some users prefer to have their firewall silently
#         "DROP" packets while others prefer to use "REJECT"
#         to send ICMP error messages back to the remote 
#         machine.  The default is "REJECT" but feel free to
#         change this below.
#
# NOTE: Without the --log-level set to "info", every single
#       firewall hit will goto ALL vtys.  This is a very big
#       pain.
#
echo "  Creating a DROP chain.."
$IPTABLES -N drop-and-log-it
$IPTABLES -A drop-and-log-it -j LOG --log-level info 
$IPTABLES -A drop-and-log-it -j REJECT

echo -e "\n   - Loading INPUT rulesets"


#######################################################################
# INPUT: Incoming traffic from various interfaces.  All rulesets are 
#        already flushed and set to a default policy of DROP. 
#

# loopback interfaces are valid.
#
$IPTABLES -A INPUT -i lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT


# local interface, local machines, going anywhere is valid
#
$IPTABLES -A INPUT -i $INTIF -s $INTNET -d $UNIVERSE -j ACCEPT

# remote interface, claiming to be local machines, IP spoofing, get lost
#
$IPTABLES -A INPUT -i $EXTIF -s $INTNET -d $UNIVERSE -j drop-and-log-it


# external interface, from any source, for ICMP traffic is valid
#
#  If you would like your machine to "ping" from the Internet, 
#  enable this next line
#
#$IPTABLES -A INPUT -i $EXTIF -p ICMP -s $UNIVERSE -d $EXTIP -j ACCEPT


# remote interface, any source, going to permanent PPP address is valid
#
$IPTABLES -A INPUT -i $EXTIF -s $UNIVERSE -d $EXTIP -j ACCEPT


# Allow any related traffic coming back to the MASQ server in
#
$IPTABLES -A INPUT -i $EXTIF -s $UNIVERSE -d $EXTIP -m state --state \
 ESTABLISHED,RELATED -j ACCEPT


# ----- Begin OPTIONAL INPUT Section -----
#

# DHCPd - Enable the following lines if you run an INTERNAL DHCPd server
#
#$IPTABLES -A INPUT -i $INTIF -p tcp --sport 68 --dport 67 -j ACCEPT
#$IPTABLES -A INPUT -i $INTIF -p udp --sport 68 --dport 67 -j ACCEPT

# HTTPd - Enable the following lines if you run an EXTERNAL WWW server
#
#    NOTE:  This is NOT needed for simply enabling PORTFW.  This is ONLY 
#           for users that plan on running Apache on the MASQ server itself
#
#echo -e "      - Allowing EXTERNAL access to the WWW server"
#$IPTABLES -A INPUT -i $EXTIF -m state --state NEW,ESTABLISHED,RELATED \
# -p tcp -s $UNIVERSE -d $EXTIP --dport 80 -j ACCEPT

#
# ----- End OPTIONAL INPUT Section -----



# Catch all rule, all other incoming is denied and logged. 
#
$IPTABLES -A INPUT -s $UNIVERSE -d $UNIVERSE -j drop-and-log-it


echo -e "   - Loading OUTPUT rulesets"

#######################################################################
# OUTPUT: Outgoing traffic from various interfaces.  All rulesets are 
#         already flushed and set to a default policy of DROP. 
#

# loopback interface is valid.
#
$IPTABLES -A OUTPUT -o lo -s $UNIVERSE -d $UNIVERSE -j ACCEPT


# local interfaces, any source going to local net is valid
#
$IPTABLES -A OUTPUT -o $INTIF -s $EXTIP -d $INTNET -j ACCEPT


# local interface, any source going to local net is valid
#
$IPTABLES -A OUTPUT -o $INTIF -s $INTIP -d $INTNET -j ACCEPT


# outgoing to local net on remote interface, stuffed routing, deny
#
$IPTABLES -A OUTPUT -o $EXTIF -s $UNIVERSE -d $INTNET -j drop-and-log-it


# anything else outgoing on remote interface is valid
#
$IPTABLES -A OUTPUT -o $EXTIF -s $EXTIP -d $UNIVERSE -j ACCEPT


# ----- Begin OPTIONAL OUTPUT Section -----
#

# DHCPd - Enable the following lines if you run an INTERNAL DHCPd server
#         - Remove BOTH #s all the #s if you need this functionality.
#
#$IPTABLES -A OUTPUT -o $INTIF -p tcp -s $INTIP --sport 67 \
# -d 255.255.255.255 --dport 68 -j ACCEPT
#$IPTABLES -A OUTPUT -o $INTIF -p udp -s $INTIP --sport 67 \
# -d 255.255.255.255 --dport 68 -j ACCEPT

#
# ----- End OPTIONAL OUTPUT Section -----


# Catch all rule, all other outgoing is denied and logged. 
#
$IPTABLES -A OUTPUT -s $UNIVERSE -d $UNIVERSE -j drop-and-log-it


echo -e "   - Loading FORWARD rulesets"

#######################################################################
# FORWARD: Enable Forwarding and thus IPMASQ
#

#- ----- Begin OPTIONAL FORWARD Section -----
#
# ----- End OPTIONAL FORWARD Section -----


echo "     - FWD: Allow all connections OUT and only existing/related IN"
$IPTABLES -A FORWARD -i $EXTIF -o $INTIF -m state --state ESTABLISHED,RELATED \
 -j ACCEPT
$IPTABLES -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT

# Catch all rule, all other forwarding is denied and logged. 
#
$IPTABLES -A FORWARD -j drop-and-log-it


#echo "     - NAT: Enabling SNAT (MASQUERADE) functionality on $EXTIF"
#
#More liberal form
#$IPTABLES -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE
#
#Stricter form
#$IPTABLES -t nat -A PREROUTING -o $EXTIF -j SNAT --to $EXTIP
$IPTABLES -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j REDIRECT --to-ports 192.168.0.1:3128
#$IPTABLES -t nat -A PREROUTING -i eth1 -p tcp --dport 80 -j DNAT --to 192.168.0.1:3128 -s ! 192.168.0.0/24
$IPTABLES -A OUTPUT -j ACCEPT -m state --state NEW -o eth0 -p tcp --dport 80
$IPTABLES -t nat -A POSTROUTING -o $EXTIF -j SNAT --to-source $EXTIP

$IPTABLES -I PREROUTING -t nat -s 192.168.0.10 -p tcp --dport 80 -j DNAT --to 192.168.0.3:3128
$IPTABLES -I PREROUTING -t nat -s 192.168.0.10 -p tcp --dport 3128 -j DNAT --to 192.168.0.3:3128
$IPTABLES -A FORWARD -s 192.168.0.10 -i eth1 -d 192.168.0.1 -o eth1 -p tcp --sport 1024:65535 --dport 3128 -j ACCEPT


#######################################################################
echo -e "\nStronger rc.firewall-2.4 $FWVER done.\n"

^ permalink raw reply	[flat|nested] 16+ messages in thread
* RE: port forwarding form IP range
@ 2006-03-13 13:13 Nilesh
  0 siblings, 0 replies; 16+ messages in thread
From: Nilesh @ 2006-03-13 13:13 UTC (permalink / raw)
  To: edvin.seferovic, netfilter

Thanks Edvin,

We have two Internet service providers.
The scenario is 192.168.0.1 is on my ISP 1 
and now I have installed second proxy server on other
comp which is 192.168.0.3 on the ISP 2 connection.
We have assigned the Ip's to our internal machines
from range 192.168.0.4 to 192.168.0.250.
We have some bandwidth upload/download limitations on
the ISP 1. 
I want to use 192.168.0.3 proxy severs for the some
IP's
I have taken example as 192.168.0.10 IP.
The browser settings of 192.168.0.10 comp is
192.168.0.1:3128

I want to setup the firewall on the 192.168.0.1 so the
request coming from 192.168.0.10 for the
192.168.0.1:3128 will forwarded to 192.168.0.3:3128
so he/she will use invisibly the proxy
192.168.0.3:3128

could you please help me to solve the problem

Nilesh. 



--- Seferovic Edvin <edvin.seferovic@kolp.at> wrote:

> Hi,
> 
> first of all an IP address should have /32 mask - or
> simply NO mask !
> 
> INTIP="192.168.0.1/24" <<< but I haven't seen the
> use of this variable in
> your script
> 
> You are prerouting http traffic to your proxy (
> squid I suppose ) which is
> running on the same machine ( 192.168.0.1 )! So you
> need 
> 
> --to-port 3128 without the IP address
> 
> $IPTABLES -t nat -A PREROUTING -i eth1 -p tcp
> --dport 80 -j REDIRECT
> --to-ports 192.168.0.1:3128 <<< 
> 
> I do NOT see the aim of this rule.. every packet
> from 192.168.0.10 to
> 192.168.0.1 ( machine with this firewall script )
> which comes on the same
> ethernet card ? There is a forward chain for the
> packets that are being
> routed. Every packet which has destination of a
> local eth card hits the
> input chain. So your following rule should be
> changed 
> 
> $IPTABLES -A FORWARD -s 192.168.0.10 -i eth1 -d
> 192.168.0.1 -o eth1 -p tcp
> --sport 1024:65535 --dport 3128 -j ACCEPT
> 
> .. to something what suits your needs !
> 
> Regards,
> 
> Edvin
> 
> -----Original Message-----
> From: Nilesh [mailto:niluforalways@yahoo.com] 
> Sent: Montag, 13. März 2006 12:39
> To: Nilesh; edvin.seferovic@kolp.at;
> netfilter@lists.netfilter.org
> Subject: RE: port forwarding form IP range
> 
> Sorry earlier mail was without attchment.
> 
> --- Nilesh <niluforalways@yahoo.com> wrote:
> 
> > no there is only Forward default chain.
> > I am confused , I have attached herewith my
> > rc.firewall  could you please look into.If I am
> > going
> > wrong way.
> > 
> > Thanks
> > Nilesh,
> > 
> > --- Seferovic Edvin <edvin.seferovic@kolp.at>
> wrote:
> > 
> > > -i eth1 -o eth1 ??? How is this suppose to work?
> > Is
> > > there any forward chain
> > > on one interface?
> > > 
> > > iptables -A FORWARD -s 192.168.0.10 -i eth1 -d
> > > 192.168.0.1 -o eth1 -p tcp --sport 1024:65535
> > > --dport
> > > 3128 -j ACCEPT.
> > > 
> > > Regards,
> > > 
> > > Edvin
> > > 
> > > --- Rob Sterenborg <rob@sterenborg.info> wrote:
> > > 
> > > > On Mon, March 13, 2006 09:53, Nilesh wrote:
> > > > > Thanks Leandro,
> > > > >
> > > > > I have tried with this rules but
> unfortunately
> > > not
> > > > > working.
> > > > > Squid server running on the 192.168.0.3 and
> > its
> > > > > working  fine. I have not installed any
> > firewall
> > > > on
> > > > > the 192.168.0.3.
> > > > > In my Internet browser settings If I chnage
> > the
> > > > > settings from 192.168.0.1:3128 to
> > > 192.168.0.3:3128
> > > > I
> > > > > can surf the web.
> > > > > but If I dont change to 192.168.0.3:3128
> proxy
> > > > > settings I get the connection timout error.
> > > > >
> > > > > I think DNAT is not working
> > > > 
> > > > Probably you tell Netfilter to do DNAT, but
> are
> > > not
> > > > allowing it.
> > > > Do you have a FORWARD rule that allows this
> > > traffic
> > > > or is your policy ACCEPT ?
> > > > 
> > > > Please don't top-post.
> > > > 
> > > > 
> > > > Gr,
> > > > Rob
> > > > 
> > > > 
> > > > > --- Leandro Silva <lansoweb@gmail.com>
> wrote:
> > > > >
> > > > >> Hello !
> > > > >>
> > > > >> You can use something like that:
> > > > >>
> > > > >> iptables -I PREROUTING -t nat -s
> 192.168.0.10
> > > -p
> > > > tcp
> > > > >> --dport 80 -j
> > > > >> DNAT --to 192.168.0.3:3128
> > > > >> iptables -I PREROUTING -t nat -s
> 192.168.0.10
> > > -p
> > > > tcp
> > > > >> --dport 3128 -j
> > > > >> DNAT --to 192.168.0.3:3128
> > > > >>
> > > > >> If you have iprange compiled for iptables
> you
> > > can
> > > > >> use:
> > > > >>
> > > > >> iptables -I PREROUTING -t nat -m iprange
> > > > --src-range
> > > > >> 192.168.0.10-192.168.0.20 -p tcp --dport 80
> > -j
> > > > DNAT
> > > > >> --to
> > > > >> 192.168.0.3:3128
> > > > >> iptables -I PREROUTING -t nat -m iprange
> > > > --src-range
> > > > >> 192.168.0.10-192.168.0.20 -p tcp --dport
> 3128
> > > -j
> > > > >> DNAT --to
> > > > >> 192.168.0.3:3128
> > > > >>
> > > > >> I hope this can help,
> > > > >> Leandro
> > > > >>
> > > > >> 2006/3/11, Nilesh
> <niluforalways@yahoo.com>:
> > > > >> > Dear all,
> > > > >> >
> > > > >> > I have two squid proxy servers and two
> ISP
> > > > >> >
> > > > >> > 1)      192.168.0.1 port 3128
> > > > >> > 2)      192.168.0.3 port 3128
> > > > >> >
> > > > >> > We have around 70 comps assigned IP's
> > between
> > > > >> > 192.168.0.4 to 192.168.0.250
> > > > >> > The default proxy we are using is
> > 192.168.0.1
> > > > >> which is
> > > > >> > on the ISP 1.
> > > > >> > Now I have configured 192.168.0.3 squid
> > proxy
> > > > >> server
> > > > >> > on ISP 2 line.
> > > > >> > Both ISP 1 and ISP 2 are landing
> > (connected)
> > > on
> > > > >> the
> > > > >> > same Switch.
> > > > >> >
> > > > >> > Now I want setup the request coming from
> IP
> > > > range
> > > > >> > (192.168.0.10 to 192.168.0.20) for the
> > > > >> > 192.168.0.1:3128
> > > > >> > Will be forward to 192.168.0.3:3128
> > > > >> > So the users from this IP range will
> access
> > > > only
> > > > >> > 192.168.0.3 proxy server.
> > > > >> >
> 
=== message truncated ===


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^ permalink raw reply	[flat|nested] 16+ messages in thread
* Re: port forwarding form IP range
@ 2006-03-14 10:54 Lexx
  0 siblings, 0 replies; 16+ messages in thread
From: Lexx @ 2006-03-14 10:54 UTC (permalink / raw)
  To: netfilter

  Try running ethereal on the macines to test your connections...
I hava a similar setup (in the nat way):
THIS IS NOT A QUESTION BUT AN ANSWER... (i'm just explaing what i did)
So my setup is like this:
1 external ip; more computers on the lan. What I required was: if one of 
the internal computers on the lan tries to connect to a dnated port it 
should start talking with the destined computer...

Basicaly it was the same from the nat point of view (dnat to the same 
interface)...
i first did the rules as you did...
and if i sent something like

lanip1 -> extip:dnatport
it would be translated in to lanip1->lnaip2:dnatport

the lanip2 machine would send back
lanip2:dnatport->lanip1 which would go directly to machine lanip1....

The problem was that the lanip1 machine was expecting an answer from 
extip:dnatport not lanip2 so it would disregard the packet sent back....
My soulution was addaing the following two rules


iptables -t nat -A POSTROUTING -o lan_interface -s 
lan_network/subnetmask -d lan_network/subnetmask -j SNAT --to-source 
lan_gw_ip
iptables -A FORWARD -i lan_interface -o lan_interface -j ACCEPT


what this two rules do is force the connection to be like
lanip1 - gw - lanip2 (so all packets pass through the gw)

in your case instead of the above two rules i think that you can also do 
something like: (on the proxy machines; i might be wrong beacuase this 
would render the gw connections table a bit off track):
iptables -A POSTROUTING -j SNAT --to-source lan_gw_ip

so all packet going to the proxy will go like lanip1 - gw - proxy
and all packets will come back proxy - lanip1 (but the source ip will be 
the gw)


If you have a better way please post it... (my gw is using a similar 
setup as i said)


Cheers,
    Silviu


Rob Sterenborg wrote:

>On Mon, March 13, 2006 12:02, Nilesh wrote:
>  
>
>>Hi Rob,
>>
>>The default FORWARD policy is ACCEPT.
>>    
>>
>
>If this is a firewall that is connected to the internet, you'd better set it
>to DROP (or have a last rule that says DROP or REJECT) and make it work with
>the state match (RELATED and ESTABLISHED)...
>
>  
>
>>Yes I am trying the rules
>>
>>iptables -I PREROUTING -t nat -s 192.168.0.10 -p tcp
>>--dport 80 -j DNAT --to 192.168.0.3:3128
>>iptables -I PREROUTING -t nat -s 192.168.0.10 -p tcp
>>--dport 3128 -j DNAT --to 192.168.0.3:3128
>>
>>iptables -A FORWARD -s 192.168.0.10 -i eth1 -d
>>192.168.0.1 -o eth1 -p tcp --sport 1024:65535 --dport
>>3128 -j ACCEPT.
>>    
>>
>
>You are PREROUTING to 192.168.0.3 but you allow forwarding to 192.168.0.1.
>That doesn't match and therefore this will not work.
>
>  
>
>>Rob, I am trying to forward all request coming from IP
>>192.168.0.10 port 3128 and 80 to 192.168.0.3 port
>>3128.
>>    
>>
>
>Let's keep it simple at first : you can always make the rule more restrictive
>if it works (and if you need to).
>
>$ipt -t nat -A PREROUTING -i eth1 -s 192.168.0.10 -p tcp \
>  --dport 3128 -j DNAT --to 192.168.0.3
>
>$ipt -A FORWARD -i eth1 -s 192.168.0.10 -d 192.168.0.3 \
>  -p tcp --dport 3128 -j ACCEPT.
>
>I must say that I've never tried forwarding "back" to the same interface..
>Don't know for sure if it's going to work.
>
>  
>
>>so 192.168.0.10 will use the 192.168.0.3 proxy server
>>not the 192.168.0.1 proxy server.
>>    
>>
>
>
>
>
>Please don't top-post.
>
>
>
>
>
>Gr,
>Rob
>
>
>
>
>
>  
>
>>--- Rob Sterenborg <rob@sterenborg.info> wrote:
>>
>>    
>>
>>>On Mon, March 13, 2006 09:53, Nilesh wrote:
>>>      
>>>
>>>>Thanks Leandro,
>>>>
>>>>I have tried with this rules but unfortunately not
>>>>working.
>>>>Squid server running on the 192.168.0.3 and its
>>>>working  fine. I have not installed any firewall
>>>>        
>>>>
>>>on
>>>      
>>>
>>>>the 192.168.0.3.
>>>>In my Internet browser settings If I chnage the
>>>>settings from 192.168.0.1:3128 to 192.168.0.3:3128
>>>>        
>>>>
>>>I
>>>      
>>>
>>>>can surf the web.
>>>>but If I dont change to 192.168.0.3:3128 proxy
>>>>settings I get the connection timout error.
>>>>
>>>>I think DNAT is not working
>>>>        
>>>>
>>>Probably you tell Netfilter to do DNAT, but are not
>>>allowing it.
>>>Do you have a FORWARD rule that allows this traffic
>>>or is your policy ACCEPT ?
>>>
>>>Please don't top-post.
>>>
>>>
>>>Gr,
>>>Rob
>>>
>>>
>>>      
>>>
>>>>--- Leandro Silva <lansoweb@gmail.com> wrote:
>>>>
>>>>        
>>>>
>>>>>Hello !
>>>>>
>>>>>You can use something like that:
>>>>>
>>>>>iptables -I PREROUTING -t nat -s 192.168.0.10 -p
>>>>>          
>>>>>
>>>tcp
>>>      
>>>
>>>>>--dport 80 -j
>>>>>DNAT --to 192.168.0.3:3128
>>>>>iptables -I PREROUTING -t nat -s 192.168.0.10 -p
>>>>>          
>>>>>
>>>tcp
>>>      
>>>
>>>>>--dport 3128 -j
>>>>>DNAT --to 192.168.0.3:3128
>>>>>
>>>>>If you have iprange compiled for iptables you can
>>>>>use:
>>>>>
>>>>>iptables -I PREROUTING -t nat -m iprange
>>>>>          
>>>>>
>>>--src-range
>>>      
>>>
>>>>>192.168.0.10-192.168.0.20 -p tcp --dport 80 -j
>>>>>          
>>>>>
>>>DNAT
>>>      
>>>
>>>>>--to
>>>>>192.168.0.3:3128
>>>>>iptables -I PREROUTING -t nat -m iprange
>>>>>          
>>>>>
>>>--src-range
>>>      
>>>
>>>>>192.168.0.10-192.168.0.20 -p tcp --dport 3128 -j
>>>>>DNAT --to
>>>>>192.168.0.3:3128
>>>>>
>>>>>I hope this can help,
>>>>>Leandro
>>>>>
>>>>>2006/3/11, Nilesh <niluforalways@yahoo.com>:
>>>>>          
>>>>>
>>>>>>Dear all,
>>>>>>
>>>>>>I have two squid proxy servers and two ISP
>>>>>>
>>>>>>1)      192.168.0.1 port 3128
>>>>>>2)      192.168.0.3 port 3128
>>>>>>
>>>>>>We have around 70 comps assigned IP's between
>>>>>>192.168.0.4 to 192.168.0.250
>>>>>>The default proxy we are using is 192.168.0.1
>>>>>>            
>>>>>>
>>>>>which is
>>>>>          
>>>>>
>>>>>>on the ISP 1.
>>>>>>Now I have configured 192.168.0.3 squid proxy
>>>>>>            
>>>>>>
>>>>>server
>>>>>          
>>>>>
>>>>>>on ISP 2 line.
>>>>>>Both ISP 1 and ISP 2 are landing (connected) on
>>>>>>            
>>>>>>
>>>>>the
>>>>>          
>>>>>
>>>>>>same Switch.
>>>>>>
>>>>>>Now I want setup the request coming from IP
>>>>>>            
>>>>>>
>>>range
>>>      
>>>
>>>>>>(192.168.0.10 to 192.168.0.20) for the
>>>>>>192.168.0.1:3128
>>>>>>Will be forward to 192.168.0.3:3128
>>>>>>So the users from this IP range will access
>>>>>>            
>>>>>>
>>>only
>>>      
>>>
>>>>>>192.168.0.3 proxy server.
>>>>>>
>>>>>>Could any one please help me which rules should
>>>>>>            
>>>>>>
>>>I
>>>      
>>>
>>>>>use
>>>>>          
>>>>>
>>>>>>in IPTABLES .
>>>>>>
>>>>>>I have attached herewith my rc.firewall file.
>>>>>>
>>>>>>Please help me.
>>>>>>
>>>>>>Regards
>>>>>>Nilesh.
>>>>>>            
>>>>>>
>
>
>
>  
>



^ permalink raw reply	[flat|nested] 16+ messages in thread
end of thread, other threads:[~2006-03-20 12:39 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2006-03-11 12:24 port forwarding form IP range Nilesh
2006-03-11 12:40 ` Leandro Silva
2006-03-13  8:53   ` Nilesh
2006-03-13  9:15     ` Rob Sterenborg
2006-03-13 11:02       ` Nilesh
2006-03-13 11:09         ` Seferovic Edvin
2006-03-13 16:22         ` Rob Sterenborg
     [not found]           ` <20060314103323.21090.qmail@web50515.mail.yahoo.com>
2006-03-14 12:12             ` Rob Sterenborg
2006-03-20  6:54               ` Nilesh
2006-03-20  9:39                 ` Nilesh
2006-03-20 12:39                 ` Rob Sterenborg
  -- strict thread matches above, loose matches on Subject: below --
2006-03-13 11:37 Nilesh
2006-03-13 11:39 Nilesh
2006-03-13 12:04 ` Seferovic Edvin
2006-03-13 13:13 Nilesh
2006-03-14 10:54 Lexx

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