Всем привет.
Пытаюсь понять проблему работы сети, не проходят соединения на некоторые ресурсы, вооружился tcpdump'ом.
Подскажите в чем отличие выводов, первый при при наличие проблемы, второй когда все ok. Адреса получателя и отправителя изменены. Srchost находится за роутером.
При наличии проблемы
root@host:~# tcpdump -i ppp0 host dsthost
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ppp0, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes
14:14:21.021231 IP dsthost.https > srchost.56741: Flags [S.], seq 833401792, ack 3165537527, win 4128, options [mss 536], length 0
14:14:21.023733 IP srchost.56741 > dsthost.https: Flags [P.], seq 1:63, ack 1, win 14600, length 62
14:14:21.026529 IP dsthost.https > srchost.56741: Flags [.], ack 63, win 32706, length 0
14:14:21.027326 IP dsthost.https > srchost.56741: Flags [P.], seq 1:537, ack 63, win 32706, length 536
14:14:23.653359 IP dsthost.https > srchost.56741: Flags [P.], seq 1:537, ack 63, win 32706, length 536
14:14:28.905829 IP dsthost.https > srchost.56741: Flags [P.], seq 1:537, ack 63, win 32706, length 536
14:14:39.406732 IP dsthost.https > srchost.56741: Flags [P.], seq 1:537, ack 63, win 32706, length 536
14:15:00.408546 IP dsthost.https > srchost.56741: Flags [P.], seq 1:537, ack 63, win 32706, length 536
Все работает нормально
root@host:~# tcpdump -i ppp0 host dsthost
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ppp0, link-type EN10MB (Ethernet), capture size 65535 bytes
14:19:20.348951 IP srchost.59457 > dsthost.https: Flags [S], seq 1506325749, win 14600, options [mss 1320,sackOK,TS val 27317338 ecr 0,nop,wscale 7], length 0
14:19:20.350818 IP dsthost.https > srchost.59457: Flags [S.], seq 4121417989, ack 1506325750, win 4128, options [mss 536], length 0
14:19:20.353086 IP srchost.59457 > dsthost.https: Flags [.], ack 1, win 14600, length 0
14:19:20.353136 IP srchost.59457 > dsthost.https: Flags [P.], seq 1:63, ack 1, win 14600, length 62
14:19:20.354965 IP dsthost.https > srchost.59457: Flags [.], ack 63, win 32706, length 0
14:19:20.355775 IP dsthost.https > srchost.59457: Flags [P.], seq 1:537, ack 63, win 32706, length 536
14:19:20.358073 IP srchost.59457 > dsthost.https: Flags [.], ack 537, win 15544, length 0
14:19:20.359824 IP dsthost.https > srchost.59457: Flags [P.], seq 537:1073, ack 63, win 32706, length 536
14:19:20.359833 IP dsthost.https > srchost.59457: Flags [P.], seq 1073:1337, ack 63, win 32706, length 264
14:19:20.362578 IP srchost.59457 > dsthost.https: Flags [.], ack 1073, win 16616, length 0
14:19:20.362623 IP srchost.59457 > dsthost.https: Flags [.], ack 1337, win 17688, length 0
14:19:20.364197 IP srchost.59457 > dsthost.https: Flags [P.], seq 63:389, ack 1337, win 17688, length 326
14:19:20.382287 IP dsthost.https > srchost.59457: Flags [P.], seq 1337:1343, ack 389, win 32380, length 6
14:19:20.382296 IP dsthost.https > srchost.59457: Flags [P.], seq 1343:1396, ack 389, win 32380, length 53
14:19:20.384456 IP srchost.59457 > dsthost.https: Flags [.], ack 1396, win 17688, length 0
14:19:20.384511 IP srchost.59457 > dsthost.https: Flags [.], seq 389:925, ack 1396, win 17688, length 536
14:19:20.384554 IP srchost.59457 > dsthost.https: Flags [P.], seq 925:975, ack 1396, win 17688, length 50
14:19:20.386165 IP dsthost.https > srchost.59457: Flags [.], ack 925, win 32380, length 0