ssh trouble feisty(client) to dapper(server)

[Juergen Sauer]

Hi!
we stumbled into a nasty problem.

After feisty-upgrade the ssh connect to a dapper server is becoming 
unstable.

Sometimes it works - sometimes not. FAQ and other resources are not 
helpful here.

Example of working try:
> jojo at pc2:~$ ssh server
> Last login: Thu Sep 20 12:12:00 2007 from pc2.s.automatix.de on pts/6
> Linux server 2.6.17.13-ax #1 SMP Tue Sep 19 16:17:15 CEST 2006 i686 > 
GNU/Linux
>        Unbuntu Dapper 6.06 Release + Universe + Multiverse
> You have new mail.
> jojo at server:~$ date
> Mo  1 Okt 12:02:14 CEST 2007
> jojo at server:~$ logout
> Connection to server closed.
> jojo at pc2:~$ ssh server
... long time nothing happens. Ctrl-C

After that I tried out a debug output:
>jojo at pc2:~$ date
>Mo 1. Okt 12:04:45 CEST 2007
>jojo at pc2:~$ ssh -vvvv server
>OpenSSH_4.3p2 Debian-8ubuntu1, OpenSSL 0.9.8c 05 Sep 2006
>debug1: Reading configuration data /etc/ssh/ssh_config
>debug1: Applying options for *
>debug2: ssh_connect: needpriv 0
>debug1: Connecting to server [192.168.11.1] port 22.
>debug2: fd 3 setting O_NONBLOCK
>debug1: fd 3 clearing O_NONBLOCK
>debug1: Connection established.
>debug1: identity file /home/jojo/.ssh/identity type -1
>debug1: identity file /home/jojo/.ssh/id_rsa type -1
>debug3: Not a RSA1 key file /home/jojo/.ssh/id_dsa.
>debug2: key_type_from_name: unknown key type '-----BEGIN'
>debug3: key_read: missing keytype
>debug3: key_read: missing whitespace
>repeaten many times<
>debug2: key_type_from_name: unknown key type '-----END'
>debug3: key_read: missing keytype
>debug1: identity file /home/jojo/.ssh/id_dsa type 2
>debug1: Remote protocol version 2.0, remote software version 
>OpenSSH_4.2p1 Debian-7ubuntu3.1
>debug1: match: OpenSSH_4.2p1 Debian-7ubuntu3.1 pat OpenSSH*
>debug1: Enabling compatibility mode for protocol 2.0
>debug1: Local version string SSH-2.0-OpenSSH_4.3p2 Debian-8ubuntu1
>debug2: fd 3 setting O_NONBLOCK
>debug1: SSH2_MSG_KEXINIT sent
>debug1: SSH2_MSG_KEXINIT received
>debug2: kex_parse_kexinit: 
>diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
>debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
>debug2: kex_parse_kexinit:  aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
> debug2: kex_parse_kexinit:  aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
> debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
>debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
>debug2: kex_parse_kexinit: none,zlib at openssh.com,zlib
>debug2: kex_parse_kexinit: none,zlib at openssh.com,zlib
>debug2: kex_parse_kexinit:
>debug2: kex_parse_kexinit:
>debug2: kex_parse_kexinit: first_kex_follows 0
>debug2: kex_parse_kexinit: reserved 0
>debug2: kex_parse_kexinit:  diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
>debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
>debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
>debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour128,arcfour256,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc at lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
>debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
>debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1-96,hmac-md5-96
>debug2: kex_parse_kexinit: none,zlib at openssh.com
>debug2: kex_parse_kexinit: none,zlib at openssh.com
>debug2: kex_parse_kexinit:
>debug2: kex_parse_kexinit:
>debug2: kex_parse_kexinit: first_kex_follows 0
>debug2: kex_parse_kexinit: reserved 0
>debug2: mac_init: found hmac-md5
>debug1: kex: server->client aes128-cbc hmac-md5 none
>debug2: mac_init: found hmac-md5
>debug1: kex: client->server aes128-cbc hmac-md5 none
>debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
>debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
>debug2: dh_gen_key: priv key bits set: 129/256
>debug2: bits set: 548/1024
>debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
>debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
>debug3: check_host_in_hostfile: filename /home/jojo/.ssh/known_hosts
>debug3: check_host_in_hostfile: match line 3
>debug3: check_host_in_hostfile: filename /home/jojo/.ssh/known_hosts
>debug3: check_host_in_hostfile: match line 37
>debug1: Host 'server' is known and matches the RSA host key.
>debug1: Found key in /home/jojo/.ssh/known_hosts:3
>debug2: bits set: 521/1024
>debug1: ssh_rsa_verify: signature correct
>debug2: kex_derive_keys
>debug2: set_newkeys: mode 1
>debug1: SSH2_MSG_NEWKEYS sent
>debug1: expecting SSH2_MSG_NEWKEYS
>debug2: set_newkeys: mode 0
>debug1: SSH2_MSG_NEWKEYS received
>debug1: SSH2_MSG_SERVICE_REQUEST sent
>debug2: service_accept: ssh-userauth
>debug1: SSH2_MSG_SERVICE_ACCEPT received
 
and nothing more hapens.
I presume, ssh in feisty is broken.

Can anyone confirm this ?

TIA
J. Sauer

-- 
Jürgen Sauer - automatiX GmbH, +49-4209-4699, juergen.sauer at automatix.de