High latency in Local Area Network

[ashique84]

Dear Team,

We have around 12 access switches and one core switch, core switch then connected to Firewall, then to router.

When i tried to ping the core switch from my pc getting a ping response maximum of 54ms- 60ms and an average of 3ms. But when i tried to ping firewall and router which is after the switch, maximum and average is 1 ms. Why could be the ping to core switch is taking more time than the router and firewall which is after the Core-Switch. Can anyone guide me on what to do to fix this? This is not affecting the network speed as of now.

[Harish Balakrishnan]

Hello Ashique

Where is the gateway of your PC configured?

regards

Harish

[ashique84]

It is configured on the core switch..

[Giuseppe Larosa]

Hello Ashique,

answering to a ping request requires process switching that is the packet has t be sent to the main cpu of the core switch that will process it.

Forwarding of user traffic between interfaces of the core switch is performed in hardware without involving the main cpu.

And answering to an ICMP echo request is not the highest priority job on the main cpu, for this reason some answers are delayed but this does not mean that network performance is poor or that there is a real trouble.

Hope to help

Giuseppe

[sivai2tech]

Yes, Giuseppe is absolutely correct. ICMP is given a least priority. If you are not seeing any performance issue, you need not to worry about the ping response. Also check if you have high load on the core switch.

Actually some vendors implement default ICMP policer that blocks excessive ICMP requests.

Thx!

~S