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Old 10-06-2011, 01:39 AM   #1
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CentOS Gateway. Packets with local IP are on the WAN interface.

Hello guys!
Throw our billing (using libpcap) I see than on external interface (eth1) on our gateway there are outbound packets with source IP from local network. This is the iptables rule for SNAT:
-t NAT -A POSTROUTING -o eth1 -j SNAT --to-source external-IP
Now I use tcpdump to shiff this packets to show it's content. But I'm confused.
Old 10-06-2011, 04:36 AM   #2
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Show routing table and content of that packets (without data).
Old 10-06-2011, 04:37 AM   #3
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Well, I've sniffed this packets and its MAC-s. It's not outgoing but incoming packets from my ISP's gateway. That's strange, but the problem has gone =)


gateway, iptables, snat

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