Cisco – Port mirroring on multiple switches

ciscomonitoring

So here is the deal, I have a server on switch A where port 3 is monitoring traffic for most of the ports on switch A. However I have other users on switch B that needs to have port 3 on switch A monitor as well. Is this possible? I have been reading about rspan but doesnt seem to work.

Switch A:

monitor session 1 source interface fast0/1 - 2
monitor session 1 source interface fast0/4 - 46
monitor session 1 destination interface fast0/3

(this works great for switch A, I need a solution to get switch B to also have some ports sent to port 3 on switch A for monitoring.)

Onxx,

All the traffic on switch A is fine, there will be about 10-15 ports on switch B that I need to send to fa0/3 on switch A as the destination. I have the switches connected with a ethernet cable with a trunk port on both switches on port 48 on switch B and A and port 47 on A connects to our sonicwall. So I am assuming they are daisy chained?

What if I did the following:

Switch A
monitor session 1 source interface fast0/1 – 2
monitor session 1 source interface fast0/4 – 46
monitor session 1 destination interface fast0/3
Put all of the ports on vlan 10 because I made an rspan vlan 10

On switch B

monitor the ports I need will say 1-10

monitor session 1 source interface fast0/1 – 10
monitor session 1 destination remote vlan 10
as a prerequisite I would have created vlan 10 as a rspan vlan on switch B.

Switch A

Monitor session 1 destination remote vlan 10

Would this work?

By the way I am working with cisco catalyst 3560 switches.

Best Answer

Thanks for updating the question and sorry for the late response.

Try this configuration instead. Just make sure the VLan ID match up and are pingable to from both switches.

======Taken from Cisco.com Rspan=====

local switch.


c3750(config)#monitor session 1 source vlan < Remote RSPAN VLAN ID >
c3750(config)#monitor session 1 source vlan 5
c3750(config)#monitor session 1 destination interface fastethernet 0/3

On the remote switch, use this configuration:

c3750_remote(config)#monitor session 1 source vlan 7
c3750_remote(config)#monitor session 1 destination remote vlan
===== End of line ======

Hope this helps.

Check this out Cisco CCNA this will bring you up to speed on the basics as a junior.

Hi Matt, Here is some extra information you should look into; these links will in understanding of how Vlans work and how to make them work together. They are both good sources of information and should be easy to follow. You dont need to use VTP for you current environment.

Additonal reading materials:

Cisco press Vlans Creating Ethernet VLANs on Catalyst Switches

Cheers,
Onxx

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