[CentOS] CentOS 5.x 32bit VPS Ping Issue

Tue Mar 8 16:43:33 UTC 2011
Les Mikesell <lesmikesell at gmail.com>

On 3/8/2011 8:57 AM, Matt wrote:
> I just got an inexpensive VPS too have an outside server to play/test
> with.  I am pinging it every 5 minutes and graphing with MRTG on
> another CentOS box.  This works fine to all servers but the VPS.  The
> first ping to the VPS is always crud and following ones are fine.
>
> [root at ns1 scripts]# ping X
> PING X 56(84) bytes of data.
> 64 bytes from X: icmp_seq=1 ttl=55 time=773 ms
> 64 bytes from X: icmp_seq=2 ttl=55 time=42.4 ms
> 64 bytes from X: icmp_seq=3 ttl=55 time=42.8 ms
> 64 bytes from X: icmp_seq=4 ttl=55 time=43.1 ms
>
> Makes my graph for that one look real bad because it looks at first
> ping only.  Thought about modifying my script to send a warm up ping
> first but I just don't think I should have to do that or is this a
> normal thing for a VPS that is pretty much idle?

How many routers are there between you and the target?  Normally they 
cache recently-used routes for a short time but have to do a more 
expensive lookup for the first access.  That probably has more of an 
effect than the target's own response.

-- 
   Les Mikesell
    lesmikesell at gmail.com