[CentOS] Slow login to system without internet connection

Tue Nov 20 19:18:37 UTC 2012
Nicolas Thierry-Mieg <Nicolas.Thierry-Mieg at imag.fr>

Ljubomir Ljubojevic wrote:
> Hi.
> For a long time I am puzzled why, when internet connection is gone
> (beyond first router, outside of subnet) SSH (and telnet?) connection is
> drastically slowed.
> Same behavior, but less impacted is observed when system boots without
> working internet connection, and I am not sure, but I think even access
> to SAMBA fileshares can be/is affected. Affected systems are mostly
> production servers, and too spaced apart in time to be able to point a
> finger in something I am doing wrong.
> I have not had time to gather more facts, I always forget/don;t have
> time, so I will only focus on definite SSH issue on CentOS 6.3, although
> I have seen same with 5.x.
> 1 server in question is set in following maner:
> [root at chiron ~]# cat /etc/networks
> default
> loopback
> link-local
> [root at chiron ~]# cat /etc/sysconfig/network
> HOSTNAME=chiron.example.com
> [root at chiron ~]# cat /etc/hosts
>	localhost localhost.localdomain localhost4
> localhost4.localdomain4 chiron.example.com chiron
> ::1	localhost localhost.localdomain localhost6 localhost6.localdomain6
> chiron.example.com chiron
> Does it have anything to do with /etc/hosts file not having row with
> used IP address, or is problem somewhere else?
> Searching the net gives too much irrelevant links, and all I need it to
> be pointed in the right direction.

perhaps due to DNS being down?

try starting sshd in debug mode (-d up to -ddd) on the server and 
connecting while the internet connection is down and see what is being