Natty Narwhal: Problems connecting to servers behind (Cisco) firewalls using ssh
After upgrading to Natty Narwhal I couldn’t connect to my Linux based jump host (connected via VPN): OpenSSH_5.8p1 Debian-1ubuntu2, OpenSSL 0.9.8o 01 Jun 2010 debug1: Reading configuration data /home/alj/.ssh/config debug1: Applying options for * debug1: Applying options for smallpox.xxx.dk debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for * debug1: Connecting to smallpox.xxx.dk [xxx.xxx.xxx.xxx] port 22. debug1: Connection established. debug1: identity file /home/alj/.ssh/id_rsa type -1 debug1: identity file /home/alj/.ssh/id_rsa-cert type -1 debug1: identity file /home/alj/.ssh/id_dsa type 2 debug1: Checking blacklist file /usr/share/ssh/blacklist.DSA-1024 debug1: Checking blacklist file /etc/ssh/blacklist.DSA-1024 debug1: identity file /home/alj/.ssh/id_dsa-cert type -1 debug1: identity file /home/alj/.ssh/id_ecdsa type -1 debug1: identity file /home/alj/.ssh/id_ecdsa-cert type -1 debug1: Remote protocol version 2.0, remote software version OpenSSH_5.5p1 Debian-4ubuntu4 debug1: match: OpenSSH_5.5p1 Debian-4ubuntu4 pat OpenSSH* debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_5.8p1 Debian-1ubuntu2 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-md5 [email protected] debug1: kex: client->server aes128-ctr hmac-md5 [email protected] debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP Read from socket failed: Connection reset by peer The key seem to be that Natty uses OpenSSH 5.8p1 – This problem seem to affect clients newer than 5.7p1, when connecting to older servers. And the problem seem to be restricted to connecting through some firewalls, I have no problem on my home network and when connecting to hosts running iptables. ...