From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Atkins Subject: RE: Natting IPs hanging Date: Thu, 19 May 2005 19:55:34 +0000 (UTC) Message-ID: <428FBAB0.8030206@tlcdelivers.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Date: Sat, 21 May 2005 15:48:16 -0700 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-bounces@lists.netfilter.org Errors-To: netfilter-bounces@lists.netfilter.org Content-Type: text/plain; charset="us-ascii"; format="flowed" To: netfilter@lists.netfilter.org Jason and John, Again, thanks for the responses. I've finally had an opportunity to dig back into it after a rather nightmare-ish week... I tried a couple of different things, without much success. First, seeing as how I'm realtively new at this, I went back to the docs on Netfilter and pulled a script out of the appedices of one of the HOWTOs and modified it for my use. Following their setup, I used it to create several new chains and new rules that I hadn't thought of implementing. Now, when I went back and checked out ip_tables_names and ip_tables_targets, I get the following: root@fw>cat /proc/net/ip_tables_names mangle nat filter root@fw>cat /proc/net/ip_tables_targets REJECT LOG DNAT SNAT Also, I checked out the kernel config and got the following list of modules that were created with the new build: root@fw>grep _NF_ /usr/src/linux/.config CONFIG_IP_NF_CONNTRACK=m # CONFIG_IP_NF_CT_ACCT is not set # CONFIG_IP_NF_CONNTRACK_MARK is not set # CONFIG_IP_NF_CT_PROTO_SCTP is not set CONFIG_IP_NF_FTP=m # CONFIG_IP_NF_IRC is not set # CONFIG_IP_NF_TFTP is not set # CONFIG_IP_NF_AMANDA is not set # CONFIG_IP_NF_QUEUE is not set CONFIG_IP_NF_IPTABLES=m CONFIG_IP_NF_MATCH_LIMIT=m CONFIG_IP_NF_MATCH_IPRANGE=m CONFIG_IP_NF_MATCH_MAC=m CONFIG_IP_NF_MATCH_PKTTYPE=m CONFIG_IP_NF_MATCH_MARK=m CONFIG_IP_NF_MATCH_MULTIPORT=m CONFIG_IP_NF_MATCH_TOS=m CONFIG_IP_NF_MATCH_RECENT=m CONFIG_IP_NF_MATCH_ECN=m CONFIG_IP_NF_MATCH_DSCP=m CONFIG_IP_NF_MATCH_AH_ESP=m CONFIG_IP_NF_MATCH_LENGTH=m CONFIG_IP_NF_MATCH_TTL=m CONFIG_IP_NF_MATCH_TCPMSS=m CONFIG_IP_NF_MATCH_HELPER=m CONFIG_IP_NF_MATCH_STATE=m CONFIG_IP_NF_MATCH_CONNTRACK=m CONFIG_IP_NF_MATCH_OWNER=m CONFIG_IP_NF_MATCH_ADDRTYPE=m CONFIG_IP_NF_MATCH_REALM=m # CONFIG_IP_NF_MATCH_SCTP is not set CONFIG_IP_NF_MATCH_COMMENT=m # CONFIG_IP_NF_MATCH_HASHLIMIT is not set CONFIG_IP_NF_FILTER=m CONFIG_IP_NF_TARGET_REJECT=m CONFIG_IP_NF_TARGET_LOG=m CONFIG_IP_NF_TARGET_ULOG=m CONFIG_IP_NF_TARGET_TCPMSS=m CONFIG_IP_NF_NAT=m CONFIG_IP_NF_NAT_NEEDED=y CONFIG_IP_NF_TARGET_MASQUERADE=m CONFIG_IP_NF_TARGET_REDIRECT=m CONFIG_IP_NF_TARGET_NETMAP=m CONFIG_IP_NF_TARGET_SAME=m CONFIG_IP_NF_NAT_SNMP_BASIC=m CONFIG_IP_NF_NAT_FTP=m CONFIG_IP_NF_MANGLE=m CONFIG_IP_NF_TARGET_TOS=m CONFIG_IP_NF_TARGET_ECN=m CONFIG_IP_NF_TARGET_DSCP=m CONFIG_IP_NF_TARGET_MARK=m CONFIG_IP_NF_TARGET_CLASSIFY=m CONFIG_IP_NF_RAW=m CONFIG_IP_NF_TARGET_NOTRACK=m CONFIG_IP_NF_ARPTABLES=m CONFIG_IP_NF_ARPFILTER=m CONFIG_IP_NF_ARP_MANGLE=m Likewise, here is what is currently loaded: root@fw>lsmod Module Size Used by ip_nat_ftp 3584 0 ip_conntrack_ftp 72976 1 ip_nat_ftp ipt_state 2560 5 ipt_limit 3072 2 iptable_mangle 3328 0 ipt_REJECT 6528 1 ipt_LOG 7552 2 iptable_nat 23868 2 ip_nat_ftp ip_conntrack 49992 4 ip_nat_ftp,ip_conntrack_ftp,ipt_state,iptable_nat iptable_filter 3328 1 ip_tables 23296 7 ipt_state,ipt_limit,iptable_mangle,ipt_REJECT,ipt_LOG,iptable_nat,iptable_filter BLADABLADABLADA Here is my routing table (for what it's worth): root@fw>route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface [OUTSIDE _NET] * 255.255.255.192 U 0 0 0 eth0 [INSIDE_NET] * 255.0.0.0 U 0 0 0 eth2 loopback localhost 255.0.0.0 UG 0 0 0 lo default [OUTSIDE_GW] 0.0.0.0 UG 0 0 0 eth0 And, finally, my current ruleset (and I welcome all critiques): root@fw>iptables-save # Generated by iptables-save v1.3.1 *mangle :PREROUTING ACCEPT [4431:597383] :INPUT ACCEPT [4387:587673] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [1709:222042] :POSTROUTING ACCEPT [1686:202254] COMMIT *nat :PREROUTING ACCEPT [2731:449771] :POSTROUTING ACCEPT [13:950] :OUTPUT ACCEPT [13:950] -A PREROUTING -d [PUBLIC_IP] -i eth0 -j DNAT --to-destination [PRIVATE_IP] -A PREROUTING -d [PUBLIC_IP] -i eth0 -j DNAT --to-destination [PRIVATE_IP] -A POSTROUTING -s [PRIVATE_IP] -o eth0 -j SNAT --to-source [PUBLIC_IP] -A POSTROUTING -s [PRIVATE_IP] -o eth0 -j SNAT --to-source [PUBLIC_IP] COMMIT *filter :ALLOWED - [0:0] :BAD_TCP_PACKETS - [0:0] :ICMP_PACKETS - [0:0] :INPUT DROP [2625:435028] :FORWARD DROP [0:0] :OUTPUT DROP [23:19788] :POSTROUTING - [0:0] :PREROUTING - [0:0] :TCP_PACKETS - [0:0] :UDP_PACKETS - [0:0] -A ALLOWED -p tcp -m tcp --tcp-flags SYN,RST,ACK SYN -j ACCEPT -A ALLOWED -p tcp -m state --state RELATED,ESTABLISHED -j ACCEPT -A ALLOWED -p tcp -j DROP -A BAD_TCP_PACKETS -p tcp -m tcp --tcp-flags SYN,ACK SYN,ACK -m state --state NEW -j REJECT --reject-with tcp-reset -A BAD_TCP_PACKETS -p tcp -m tcp ! --tcp-flags SYN,RST,ACK SYN -m state --state NEW -j DROP -A ICMP_PACKETS -s [PRIVATE_NET]/255.0.0.0 -p icmp -j ACCEPT -A ICMP_PACKETS -s [PUBLIC_NET]/255.255.255.192 -p icmp -j ACCEPT -A ICMP_PACKETS -s 127.0.0.0/255.0.0.0 -p icmp -j ACCEPT -A ICMP_PACKETS -p icmp -m icmp --icmp-type 3/4 -j ACCEPT -A INPUT -j PREROUTING -A INPUT -p tcp -j BAD_TCP_PACKETS -A INPUT -s 127.0.0.1 -i lo -j ACCEPT -A INPUT -s [PRIVATE_IP_FW] -i lo -j ACCEPT -A INPUT -s [PUBLIC_IP_FW] -i lo -j ACCEPT -A INPUT -d [PUBLIC_IP_FW] -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p tcp -j TCP_PACKETS -A INPUT -p udp -j UDP_PACKETS -A INPUT -p icmp -j ICMP_PACKETS -A FORWARD -p tcp -j BAD_TCP_PACKETS -A FORWARD -d [PUBLIC_NET]/255.255.255.192 -p tcp -j PREROUTING -A FORWARD -p icmp -m icmp --icmp-type 3/4 -j ICMP_PACKETS -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -m limit --limit 3/min --limit-burst 3 -j LOG --log-prefix "IPT FORWARD packet died: " --log-level 7 -A OUTPUT -s 127.0.0.1 -j ACCEPT -A OUTPUT -s [PRIVATE_IP_FW] -j ACCEPT -A OUTPUT -s [PUBLIC_IP_FW] -j ACCEPT -A OUTPUT -m limit --limit 3/min --limit-burst 3 -j LOG --log-prefix "IPT OUTPUT packet died: " --log-level 7 -A TCP_PACKETS -p tcp -m tcp --dport 21 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 22 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 25 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 80 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 443 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 873 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 1999 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 4899 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 5666 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 8080 -j ALLOWED -A TCP_PACKETS -p tcp -m tcp --dport 11371 -j ALLOWED -A UDP_PACKETS -p udp -m udp --sport 53 -j ACCEPT -A UDP_PACKETS -p udp -m udp --sport 123 -j ACCEPT -A UDP_PACKETS -p udp -m udp --sport 873 -j ACCEPT COMMIT # Completed I also tried FireHOL to build the rules from a config file. I liked how *through* it appeared to be, but I went back to the original script for troubleshooting purposes. -- Brian Atkins IT Services The Library Corporation http://TLCdelivers.com Ph: 800.624.0559