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How to check port mirroring is working or not?

vinothlb1
Beginner
Beginner

How to check port mirroring is working or not?

It was configured like this

monitor session 1 source interface Gi2/10

monitor session 1 destination interface

Gi2/9 ingress vlan 1

what does this indiacets?

6 Replies 6

Giuseppe Larosa
Hall of Fame Master Hall of Fame Master
Hall of Fame Master

Hello Vinoth,

you can check with

sh monitor session

source port is Gi2/10

destination port is Gi2/9 the option ingress vlan1 is more specific

ingress should stand only for the inbund direction on the source port and frames in vlan1.

I tried to look at the command reference but I didn't find this option listed.

What platform and IOS image are you using ?

Hope to help

Giuseppe

I have given the sh monitor session but how to know port mirroring it is working or not.. Is there any link pls provide..?

Hello Vinoth,

look here

http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/configuration/guide/span.html#wp1047048

if you like you can post the show in this thread

Hope to help

Giuseppe

Look at the device (Sniffer, IDS, etc...) to which your mirroring traffic to.

cisco_lad2004
Contributor
Contributor

I concur with James, the only way you are 100% positive is:

1-Check your sniffer is receiving data.

2-Even when you see data, remove SPAN port config to make sure the data you see on sniffer is your session (I usually shut the port I am spanning if its not service affecting). The reason is that I have seen that sometimes sniffer is getting all sort of junk you are not really spanning for, especially when using ERSPAN.

HTH

Sam

install Wireshark on your system. Connect laptop on span port and then start capturing Span port traffic. If you see traffic coming from mentioned source then it is working fine.

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