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Ingress command for SPAN Destination Port - 3550


I use this command on two identical switches to enable ingress traffic on destination monitor port:

monitor session 1 destination interface fa0/37 ingress vlan 1.

This works to allow remote connect via the LAN to a portable using sniffer software on one of the switches but on the other switch the portable is using Ethereal and cannot be connected to via the LAN.

The portable using Sniffer has NIC with enhanced drivers from software developer of Sniffer; the other portable has no special drivers.

Question: what is going on with the second switch with the portable that I cannot connect to via the LAN?

Thanks in advance for the help.


Re: Ingress command for SPAN Destination Port - 3550

ingress feature would allow the PC being used to take sniffer capture to participate in the traffic, in your case vlan 1 traffic. The issue sounds to me like an issue with the Ethereal where it might not be able to allow the NIC to do both caopturing and rx/tx regular traffic for the PC/Laptop. One thing you can do to make sure this is the case, is to swap the connection of the device with Sniffer and device with Ethereal, if the issue follows the Etereal, then that will confirm it has to do with Ethereal, you might have to tweak it. Have you tried having the Ethereal in promiscuos mode? I am not familiar with Ethereal, so you might have to paly with it.

Community Member

Re: Ingress command for SPAN Destination Port - 3550


Thanks for the comment.

After SPAN is configured with destination port ingress enabled one cannot connect or ping the portable even if Ethereal is not running.

Could it be the a NIC driver limitation?

As soon as possible I will swap portables around and check your suggestion.

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