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Embedded packet capture not capturing packets from outside LAN

dragojlo
Level 1
Level 1

HI all,

I have Catalyst 4500 L3 Switch and I am trying to capture some packets with EPC from outside my LAN but I see only packets coming from inside my network. I have configured my access list for EPC like this:

permit ip any host xx.xx.xx.x

permit ip host xx.xx.xx.x any

I want to see the packets for only one ip address. So when I ping ip address from my switch I see the packets coming. But when I try to ping it from outside my network nothing is coming. The IP address is definitely reachable from outside. I think the EPC is configured properly because I wouldn't see any packets at all. Does someone maybe know what might be the problem?

1 Accepted Solution

Accepted Solutions

there are CEF and process switching, 
remove the CEF from capture and check again (make the direction BOTH).

Thanks A Lot
MHM

View solution in original post

8 Replies 8

Torbjørn
Spotlight
Spotlight

Is the 4500 performing NAT on the traffic?

Happy to help! Please mark as helpful/solution if applicable.
Get in touch: https://torbjorn.dev

No, there is no NAT configured on the switch.

do you apply the packet capture control-plane IN or OUT direction ??

Thanks A Lot
MHM

I have set it to be both direction. Like this:

monitor capture point ip cef POINT vlan 45 both

I forgot to mention that it is a vlan interface but as I said the IP address is definitely reachable from outside so I don't know if it matters.

there are CEF and process switching, 
remove the CEF from capture and check again (make the direction BOTH).

Thanks A Lot
MHM

I removed CEF and now I can see some packets from outside but they are not mine. When I ping and ssh to my host I still don't see that packets coming. Could a host somehow be blocking to see the packets? Thanks for help MHM, I am new to this and I am still learning.

Use from-us to check ping/ssh/telnet from SW or to SW. 

Thank you for help

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