Switching : How to debug simply to see frames ?

[akosomba]

Good morning,

I'm new to and working on Catalyst 9xxx Switches.

When I debug, I would like to visualize the frames that circulate on a VLAN. For example to know if a PC is communicating well with a remote server.
For example, I would like to know if a PC (which is connected on a stack) communicates well with a remote DHCP server. I would like to see DHCP frames and DHCP packets (@MACs, ips, Ports, etc).

My constraints are:
- The stack does not host the VLAN gateway where the PC is connected.
- Stack has no DHCP service. The DHCP server is not on the stack but it is remote.
- The visualization must be live (and therefore without capture) to facilitate debugging.

How do we do it ?

THANKS.

[Flavio Miranda]

Hi @akosomba 

 In the switch CLI is not possible.

I see two alternatives for this.

  Port span  - you configure one interface as span to receive all traffic and you connect one PC running wireshark on it. You will see all traffic , at least for one vlan.

Second would be install the wireshark on the switch ittself

You can check here

https://community.cisco.com/t5/networking-knowledge-base/let-s-talk-about-wireshark-and-embedded-packet-capture-on-cat9k/ta-p/4590386