Port Mirror

[Noovi]

Hi,

I am having one Cisco 3850 switch and i want to know about SPAN.

monitor session 1 destinationinterface Te1/0/1

monitor session 1 source interfaceTe1/0/2

monitor session 1 source interface Te1/0/3

.

.

?

My question is , what is the max limit to put interface in source?

Also if i keep around 10 interface as a source then any impact on CPU utilization of the switch?

[Jerome BERTHIER · Accepted solution]

Hi

All is documented here :

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3se/network_management/configuration_guide/b_nm_3se_3850_cg/b_nm_3se_3850_cg_chapter_0111.html

No impact is generaly expected but if you redirect a lot of source interfaces to the same SPAN destination thant it will be a bottleneck and you will loose packets.

Regards

[Noovi]

Thanks Jerome,Paul

[paul driver · Accepted solution]

Hello

You can have multiple source span ports and mirroring can cause network disruption depending how much traffic you’re mirroring - I am not saying it will cause you disruption but the potential is there for it to do so.

I would suggest when you enable your span session that keep an eye on the cpu/memory utilization of the switch, if applicable take a pre/post baseline check.