Antony Stone <Antony@xxxxxxxxxxxxxxxxxxxx> writes: > Ah. Sorry if my previous response seemed a little terse - I did not realise > you were aware of iproute2 and had tried so much of it already. Don't be sorry, your assumption was perfectly valid. > >> I think my problem is that I need this to work from the host with the >> connections to the providers. (localhost). >> >> My next thought was to use iptables to add a SNAT rule. But SNAT is only >> allowed in POSTROUTING, and I think I would need that in OUTPUT > > I would recommend that you do try such a rule, since POSTROUTING happens after > OUTPUT (and FORWARD). > > Try: > > iptables -A POSTROUTING -t nat -p tcp --dport 25 -j SNAT --to 217.215.183.181 > Ok, that almost makes it work. tcpdump shows the packets with the correct sourceaddr, and I can see the returnpackets also. But they doesn't seem to reach my telnet process, because it just sits waiting. $telnet vishnu.netfilter.org 25 Trying 213.95.27.115... tcpdump -n -i eth1 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth1, link-type EN10MB (Ethernet), capture size 68 bytes 02:16:07.089217 IP 217.215.183.181.48896 > 213.95.27.115.25: SWE 1634311290:1634311290(0) win 5840 <mss 1460,sackOK,timestamp 69511424[|tcp]> 02:16:07.145586 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573673968[|tcp]> 02:16:10.086584 IP 217.215.183.181.48896 > 213.95.27.115.25: SWE 1634311290:1634311290(0) win 5840 <mss 1460,sackOK,timestamp 69511724[|tcp]> 02:16:10.142648 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573674267[|tcp]> 02:16:11.144472 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573674368[|tcp]> 02:16:12.086600 arp who-has 217.215.183.1 tell 217.215.183.181 02:16:12.099187 arp reply 217.215.183.1 is-at 00:20:1a:06:d9:19 02:16:16.086737 IP 217.215.183.181.48896 > 213.95.27.115.25: SWE 1634311290:1634311290(0) win 5840 <mss 1460,sackOK,timestamp 69512324[|tcp]> 02:16:16.143331 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573674867[|tcp]> 02:16:17.145349 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573674968[|tcp]> 02:16:28.087024 IP 217.215.183.181.48896 > 213.95.27.115.25: SWE 1634311290:1634311290(0) win 5840 <mss 1460,sackOK,timestamp 69513524[|tcp]> 02:16:28.143251 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573676067[|tcp]> 02:16:29.146786 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573676168[|tcp]> 02:16:52.087641 IP 217.215.183.181.48896 > 213.95.27.115.25: SWE 1634311290:1634311290(0) win 5840 <mss 1460,sackOK,timestamp 69515924[|tcp]> 02:16:52.144701 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573678467[|tcp]> 02:16:53.150064 IP 213.95.27.115.25 > 217.215.183.181.48896: S 294755035:294755035(0) ack 1634311291 win 5792 <mss 1460,sackOK,timestamp 573678568[|tcp]> -- Christer
