[CentOS] Not firewall, but what?

Fri May 7 08:01:17 UTC 2010
Simon Billis <simon at houxou.com>

Hi,

Philippe Naudin sent a missive on 2010-05-07:

> Le Fri, 07 May 2010 07:38:45 +0300,
> Jussi Hirvi a écrit :
> 
>> ...
>> You could test yourself if you can see
>> 	http://62.236.221.71 (the problem system)
>> 	http://62.236.221.78 (another guest on the same xen host)
>> 
>> If someone *cannot* see the 1st one, then it would be interesting to
>> know if (s)he can see the 2nd one or not.
> 
> It is the case from 147.99.7.1, and not only for port 80 :
> 
> $ ping -c 10 62.236.221.71
> PING 62.236.221.71 (62.236.221.71) 56(84) bytes of data.
> 
> --- 62.236.221.71 ping statistics ---
> 10 packets transmitted, 0 received, 100% packet loss, time 8998ms
> 
> $ ping -c 1 62.236.221.78
> PING 62.236.221.78 (62.236.221.78) 56(84) bytes of data.
> 64 bytes from 62.236.221.78: icmp_seq=1 ttl=46 time=58.9 ms
> 
> --- 62.236.221.78 ping statistics ---
> 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt
> min/avg/max/mdev = 58.975/58.975/58.975/0.000 ms
>

Can you confirm the routing on the two boxes - is there anything different?
I would also check the routing on the upstream routers - it is possible that
one of your ingress/egress routers has a static entry that is causing
issues. I would check all the routers that are inside the 62.236.0.0/15
subnet (BGP thinks that these addresses are part of that subnet).

Simon.