On Linux 2.4.14 with the following iptables rule, iptables -t nat -A POSTROUTING -o eth1 -p tcp -d $TARGET -j SNAT --to $NEW
tcpdump version 3.6.2 with libpcap 0.6.2 (Debian GNU/Linux versions) shows the address on the wire for source addresses of IP packets, but the destination address is displayed with NAT applied, which is quit confusing. Sample output ($ORIG is the local address without NAT). There is an aliased interface for $NEW and $ORIG on the host on which tcpdump is running. Running tcpdump on the destination host shows that only $NEW is used. 20:51:12.421778 $NEW.3068 > $TARGET.119: SWE 3333853624:3333853624(0) win 5840 <mss 1460,sackOK,timestamp 70130986 0,nop,wscale 0> (DF) [tos 0x10] 20:51:12.465066 $NEW.119 > $ORIG.3068: S 3130380818:3130380818(0) ack 3333853625 win 5792 <mss 1460,sackOK,timestamp 519229759 701309 86,nop,wscale 0> (DF) 20:51:12.465316 $NEW.3068 > $TARGET.119: . ack 3130380819 win 5840 <nop,nop,timestamp 70130991 519229759> (DF) [tos 0x10] - This is the TCPDUMP workers list. It is archived at http://www.tcpdump.org/lists/workers/index.html To unsubscribe use mailto:[EMAIL PROTECTED]?body=unsubscribe
