* RE: Complex NAT problems /sorry for the formated text
@ 2004-05-20 11:45 CPD - David Cardeñosa Rubio
2004-05-20 14:07 ` John A. Sullivan III
0 siblings, 1 reply; 2+ messages in thread
From: CPD - David Cardeñosa Rubio @ 2004-05-20 11:45 UTC (permalink / raw)
To: netfilter
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Hi
I have a strage problem with iptables NAT
I try to join 2 net with the same ip.
fwinet-2:~# iptables -L -n -t nat -v
Chain PREROUTING (policy ACCEPT 41232 packets, 2376K bytes)
pkts bytes target prot opt in out source
destination
94 4743 NETMAP all -- eth2 * 172.0.0.0/8
172.20.4.0/24 172.16.4.0/24
7 420 NETMAP all -- eth1 * 172.16.4.0/24
172.20.3.0/24 172.16.33.0/24
Chain POSTROUTING (policy ACCEPT 21845 packets, 1167K bytes)
pkts bytes target prot opt in out source
destination
0 0 NETMAP all -- * eth1 172.16.33.0/24
172.16.4.0/24 172.20.3.0/24
654 33367 NETMAP all -- * eth2 172.16.4.0/24
172.0.0.0/8 172.20.4.0/24
0 0 SNAT all -- * eth0 172.16.0.0/16
0.0.0.0/0 to:192.168.8.6
0 0 SNAT all -- * eth0 172.40.40.0/22
0.0.0.0/0 to:192.168.8.6
0 0 SNAT all -- * eth0 172.60.60.0/24
0.0.0.0/0 to:192.168.8.6
394 32515 SNAT all -- * eth0 10.152.24.100
0.0.0.0/0 to:192.168.8.6
0 0 MASQUERADE all -- * eth1 0.0.0.0/0
172.16.4.14
Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
pkts bytes target prot opt in out source
destination
The 1º rule in POSTROUTING table don´t work, the packets go to the inteface
eth1 with the original ip, i have the same problem for the other NETMAP
rules(i also try with SNAT/DNAT) but when y reboot de firewall the rules
apply correctly.
This only happend when modify the rules and no reboot, if reboot and load
the firewall script (with the new rules) all work ok.
fwinet-2:~# tcpdump -i eth2 -n icmp
tcpdump: listening on eth2
13:25:38.157106 172.16.33.1 > 172.20.4.11: icmp: echo request
13:25:39.158705 172.16.33.1 > 172.20.4.11: icmp: echo request
fwinet-2:~# tcpdump -i eth1 -n icmp
tcpdump: listening on eth1
13:25:43.163094 172.16.33.1 > 172.16.4.11: icmp: echo request
It´s very strange.
fwinet-2:~# uname -a
Linux fwinet-2 2.4.26 #2 Mon May 17 21:11:05 CEST 2004 i686 unknown
gretings
David Cardeñosa
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^ permalink raw reply [flat|nested] 2+ messages in thread
* RE: Complex NAT problems /sorry for the formated text
2004-05-20 11:45 Complex NAT problems /sorry for the formated text CPD - David Cardeñosa Rubio
@ 2004-05-20 14:07 ` John A. Sullivan III
0 siblings, 0 replies; 2+ messages in thread
From: John A. Sullivan III @ 2004-05-20 14:07 UTC (permalink / raw)
To: CPD - David Cardeñosa Rubio; +Cc: netfilter
On Thu, 2004-05-20 at 07:45, CPD - David Cardeñosa Rubio wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
>
>
>
> Hi
>
> I have a strage problem with iptables NAT
>
> I try to join 2 net with the same ip.
>
>
> fwinet-2:~# iptables -L -n -t nat -v
> Chain PREROUTING (policy ACCEPT 41232 packets, 2376K bytes)
> pkts bytes target prot opt in out source
> destination
> 94 4743 NETMAP all -- eth2 * 172.0.0.0/8
> 172.20.4.0/24 172.16.4.0/24
> 7 420 NETMAP all -- eth1 * 172.16.4.0/24
> 172.20.3.0/24 172.16.33.0/24
>
> Chain POSTROUTING (policy ACCEPT 21845 packets, 1167K bytes)
> pkts bytes target prot opt in out source
> destination
> 0 0 NETMAP all -- * eth1 172.16.33.0/24
> 172.16.4.0/24 172.20.3.0/24
> 654 33367 NETMAP all -- * eth2 172.16.4.0/24
> 172.0.0.0/8 172.20.4.0/24
> 0 0 SNAT all -- * eth0 172.16.0.0/16
> 0.0.0.0/0 to:192.168.8.6
> 0 0 SNAT all -- * eth0 172.40.40.0/22
> 0.0.0.0/0 to:192.168.8.6
> 0 0 SNAT all -- * eth0 172.60.60.0/24
> 0.0.0.0/0 to:192.168.8.6
> 394 32515 SNAT all -- * eth0 10.152.24.100
> 0.0.0.0/0 to:192.168.8.6
> 0 0 MASQUERADE all -- * eth1 0.0.0.0/0
> 172.16.4.14
>
> Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
> pkts bytes target prot opt in out source
> destination
>
>
> The 1º rule in POSTROUTING table don´t work, the packets go to the
> inteface eth1 with the original ip, i have the same problem for the
> other NETMAP rules(i also try with SNAT/DNAT) but when y reboot de
> firewall the rules apply correctly.
>
> This only happend when modify the rules and no reboot, if reboot and
> load the firewall script (with the new rules) all work ok.
>
>
> fwinet-2:~# tcpdump -i eth2 -n icmp
> tcpdump: listening on eth2
> 13:25:38.157106 172.16.33.1 > 172.20.4.11: icmp: echo request
> 13:25:39.158705 172.16.33.1 > 172.20.4.11: icmp: echo request
>
> fwinet-2:~# tcpdump -i eth1 -n icmp
> tcpdump: listening on eth1
> 13:25:43.163094 172.16.33.1 > 172.16.4.11: icmp: echo request
>
> It´s very strange.
>
> fwinet-2:~# uname -a
> Linux fwinet-2 2.4.26 #2 Mon May 17 21:11:05 CEST 2004 i686 unknown
<snip>
I can't give you an easy answer but I can suggest some process. Have
you compared the rule listings before and after a change? Have you
placed logging rules within your rule set to see where the packets are
being unexpectedly accepted or dropped?
--
John A. Sullivan III
Chief Technology Officer
Nexus Management
+1 207-985-7880
john.sullivan@nexusmgmt.com
---
If you are interested in helping to develop a GPL enterprise class
VPN/Firewall/Security device management console, please visit
http://iscs.sourceforge.net
^ permalink raw reply [flat|nested] 2+ messages in thread
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2004-05-20 11:45 Complex NAT problems /sorry for the formated text CPD - David Cardeñosa Rubio
2004-05-20 14:07 ` John A. Sullivan III
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