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@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?
Sounds like the remote router is having to ARP to find the MAC address of your VPS server. Perhaps its ARP cache is full or it has a relatively short ARP cache TTL. Cisco routers, by default, have a 4 hour timeout. I can't imagine a router having < 5 minute timeout. You could test this by running a network capture on the VPS to see if the gateway is frequently ARPing for your VPS IP.
Either way, I'd report the issue to your hosting provider and see if they have an answer.
--Blake
-------- Original Message -------- Subject: [CentOS] CentOS 5.x 32bit VPS Ping Issue From: Matt lm7812@gmail.com To: CentOS mailing list centos@centos.org Date: Tuesday, March 08, 2011 8:57:42 AM
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@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? _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
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@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.
-
Blake Hudson -
Les Mikesell -
Matt