My home Ubuntu Jaunty installation often takes a good 40-60 seconds to connect to using SSH, none of the other servers I maintain have this same problem, they’re pretty much instantaneous, and today, on a Friday evening at 1am this irked me enough to fix it!
The first step is of course to make the SSH connection with debug output on.
<br /> Chill:~ idimmu$ ssh -v cordy<br /> OpenSSH_5.2p1, OpenSSL 0.9.7l 28 Sep 2006<br /> debug1: Reading configuration data /Users/idimmu/.ssh/config<br /> debug1: Reading configuration data /etc/ssh_config<br /> debug1: Connecting to cordy [192.168.0.10] port 22.<br /> debug1: Connection established.<br /> debug1: identity file /Users/idimmu/.ssh/identity type -1<br /> debug1: identity file /Users/idimmu/.ssh/id_rsa type -1<br /> debug1: identity file /Users/idimmu/.ssh/id_dsa type 2<br /> debug1: Remote protocol version 2.0, remote software version OpenSSH_5.1p1 Debian-5ubuntu1<br /> debug1: match: OpenSSH_5.1p1 Debian-5ubuntu1 pat OpenSSH*<br /> debug1: Enabling compatibility mode for protocol 2.0<br /> debug1: Local version string SSH-2.0-OpenSSH_5.2<br /> debug1: SSH2_MSG_KEXINIT sent<br /> debug1: SSH2_MSG_KEXINIT received<br /> debug1: kex: server->client aes128-ctr hmac-md5 none<br /> debug1: kex: client->server aes128-ctr hmac-md5 none<br /> debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<br /> debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP<br /> debug1: SSH2_MSG_KEX_DH_GEX_INIT sent<br /> debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY<br /> debug1: Host 'cordy' is known and matches the RSA host key.<br /> debug1: Found key in /Users/idimmu/.ssh/known_hosts:7<br /> debug1: ssh_rsa_verify: signature correct<br /> debug1: SSH2_MSG_NEWKEYS sent<br /> debug1: expecting SSH2_MSG_NEWKEYS<br /> debug1: SSH2_MSG_NEWKEYS received<br /> debug1: SSH2_MSG_SERVICE_REQUEST sent<br /> debug1: SSH2_MSG_SERVICE_ACCEPT received