Management interface ICMP not stable.

[info]

Hello,

I would need your help, I'm trying to understand why a simple iCMP monitoring is not stable on two SG350X-24F. FYI, no traffic on the network for the moment.

The path:

PRTG -- 10Gbps -- FW -- 10Gbps -- SG350 -- MPLS 2Gbps -- SG350 -- 1Gbps -- FW

Latency

PRTG -- FW (0msec) -- SG350 (1msec) -- SG350 (12-15 msec) -- FW (12msec)

- --------

The issue: on both SG350, the ping is not stable and this is really important on the second one after the MPLS which is more  understandable but the last FW is perfectly stable with a flat line.

Second SSG350X:

And the FW

I've read in some post that I quote "routers and switches are specifically tuned to pass traffic, not to respond quickly" ?!?

I've audio traffic issue on this network and my current stats are pointing to a lack of stability on the MPLS but maybe the information that I receive from the switch is wrong.

Regards

Laurent

[Seb Rupik]

Hi there,

ICMP traffic that is destined to the switch will be handled by the CPU. Depending on the switch control plane workload and CPU spec this can cause high CPU utilization which will manifest itself with high latency and jitter when graphing the ICMP responses from the device. This correlates with the quote you provided.

Can you view the CPU stats on the switch? 

cheers,

Seb.

[info]

Hello,

I've understood that following some posts. The tests have been executed this week-end with no traffic.

Now the network is used and the CPU is less than 20 percent. I can understand that behaviour when the switch is heavily charged but not with less than 20 percent.

How am I supposed to monitor my MPLS link or some other connections properly if I can't trust this information ? 

Regards,

Laurent