An ICMP echo-request requires the CPU on the other side to respond with an ICMP echo-reply. It's quite low priority on the CPU so if it's busy doing something else that reply will be delayed. ICMP is not a great test for latency through a router.
Thanks Darren http://www.mellowd.co.uk/ccie > From: [email protected] > Date: Thu, 31 Jul 2014 12:10:55 +0700 > To: [email protected] > Subject: [c-nsp] Latency Spike > > Hi All, > > Just experienced spike when doing the continuous ping as the result below: > > 64 bytes from x.x.152.3: icmp_seq=421 ttl=255 time=3.53 ms > > 64 bytes from x.x.152.3: icmp_seq=422 ttl=255 time=2.40 ms > > 64 bytes from x.x.160.152.3: icmp_seq=423 ttl=255 time=1.49 ms > > 64 bytes from x.x.152.3: icmp_seq=424 ttl=255 time=3.15 ms > > 64 bytes from x.x.152.3: icmp_seq=425 ttl=255 time=2.05 ms > > *64 bytes from x.x.152.3: icmp_seq=426 ttl=255 time=107 ms* > > 64 bytes from x.x.152.3: icmp_seq=427 ttl=255 time=47.4 ms > > 64 bytes from x.x.152.3: icmp_seq=428 ttl=255 time=3.77 ms > > 64 bytes from x.x.152.3: icmp_seq=429 ttl=255 time=1.12 ms > > 64 bytes from x.x.152.3: icmp_seq=430 ttl=255 time=1.35 ms > > --- x.x.152.3.152.3 ping statistics --- > > 500 packets transmitted, 500 received, 0% packet loss, time 25285ms > > *rtt min/avg/max/mdev = 0.634/4.021/107.242/9.067 ms, pipe 2* > > > I tested this segment by segment (point to point) between the two devices, > and I still see this latency spike. I assume this is normal in the network > as router/switch needs time to calculate and send back to source. > > > Is There anyone experienced this or anything can cause this ? > > > Regards, > > -- > Samol Khoeurn > (855) 077 55 64 02 / (855) 067 41 88 66 > Network Engineer > Cisco: CCNA/CCNP SP/CCIP/ > Juniper: JNCIA/JNCIS-ENT,SP,SEC/JNCIP-ENT > www.linkedin.com/in/samolkhoeurn > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
