Доброе время суток, с некоторых пор на одном из серверов столкнулся с такой проблемой:
не получается зайти через ssh при том что телнет на 22 порт показывает обычное поведение, гуглирование не помогло

на стороне сервера: Gentoo, OpenSSH_5.2p1, OpenSSL 0.9.8j 07 Jan 2009
в логах - ничего относящегося к косякам ссш

20:23:17.226282 IP 77.52.253.246.49395 > kmfgw.example.com.ssh: Flags [S], seq 662402446, win 5040, options [mss 1260,sackOK,TS[|tcp]>
20:23:17.226315 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [S.], seq 702756119, ack 662402447, win 5792, options [mss 1460,sackOK,TS[|tcp]>
20:23:17.297184 IP 77.52.253.246.49395 > kmfgw.example.com.ssh: Flags [.], ack 1, win 79, options [nop,nop,TS[|tcp]>
20:23:17.302511 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 1, win 724, options [nop,nop,TS[|tcp]>
20:23:17.380263 IP 77.52.253.246.49395 > kmfgw.example.com.ssh: Flags [.], ack 31, win 79, options [nop,nop,TS[|tcp]>
20:23:17.385177 IP 77.52.253.246.49395 > kmfgw.example.com.ssh: Flags [P.], ack 31, win 79, options [nop,nop,TS[|tcp]>
20:23:17.385205 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:17.386272 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:17.670180 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:18.250177 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:19.410218 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:21.730173 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:26.370213 IP kmfgw.example.com.ssh > 77.52.253.246.49395: Flags [P.], ack 40, win 724, options [nop,nop,TS[|tcp]>
20:23:28.250705 IP kmfgw.example.com.ssh > 77.52.253.246.49391: Flags [F.], seq 653689326, ack 4190042739, win 724, options [nop,nop,TS[|tcp]>

клиент: Ubuntu 8.10, OpenSSH_5.1p1 Debian-3ubuntu1, OpenSSL 0.9.8g 19 Oct 2007

20:22:30.803779 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: S 4190042699:4190042699(0) win 5040 <mss 1260,sackOK,timestamp 9426985 0,nop,wscale 6>
20:22:30.878382 IP kmfgw.example.com.ssh > 77.52.253.246.49391: S 653688511:653688511(0) ack 4190042700 win 5792 <mss 1460,sackOK,timestamp 958081385        9426985,nop,wscale 3>
20:22:30.878481 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: . ack 1 win 79 <nop,nop,timestamp 9427004 958081385>
20:22:30.953371 IP kmfgw.example.com.ssh > 77.52.253.246.49391: P 1:31(30) ack 1 win 724 <nop,nop,timestamp 958081392 9427004>
20:22:30.953462 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: . ack 31 win 79 <nop,nop,timestamp 9427023 958081392>
20:22:30.953740 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 1:40(39) ack 31 win 79 <nop,nop,timestamp 9427023 958081392>
20:22:31.036389 IP kmfgw.example.com.ssh > 77.52.253.246.49391: . ack 40 win 724 <nop,nop,timestamp 958081400 9427023>
20:22:31.036458 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9427043 958081400>
20:22:31.309188 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9427112 958081400>
20:22:31.862224 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9427250 958081400>
20:22:32.965186 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9427526 958081400>
20:22:35.174751 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9428078 958081400>
20:22:37.529176 IP 77.52.253.246.49374 > kmfgw.example.com.ssh: P 3164744939:3164745731(792) ack 586984215 win 79 <nop,nop,timestamp 9428667 2858381196>
20:22:39.589175 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9429182 958081400>
20:22:48.421182 IP 77.52.253.246.49391 > kmfgw.example.com.ssh: P 40:832(792) ack 31 win 79 <nop,nop,timestamp 9431390 958081400>

залипает после таких строк

sha-nb:/soft# ssh -v sha@kmfgw.example.com
OpenSSH_5.1p1 Debian-3ubuntu1, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to kmfgw.example.com [74.xx.xx.113] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type -1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.2
debug1: match: OpenSSH_5.2 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.1p1 Debian-3ubuntu1
debug1: SSH2_MSG_KEXINIT sent

кто то может сталкивался?