Cisco Support Community
Community Member

Cisco 7606 and ES20 span port problem

Is there any way to SPAN(mirror) TX and RX on an Cisco 7606 router with an ES20 card (for downlink - with attached DSLAMs) .

When i try to SPAN the TX i get the following error:

- % EVC port Gi4/0/0 cannot be SPAN TX monitor source due to platform limitation

is there any way to mirror the RX+TX flow  (maybe with netflow? - i don't have access to the router at the moment)

Hall of Fame Super Silver

Re: Cisco 7606 and ES20 span port problem


be aware of SPAN limitations on ES20 :

Switch Port Analyzer (SPAN) Restrictions

Follow these SPAN restrictions when you configure a ES20 line card on the Cisco 7600 series router:

SPAN is not supported on EVC ports.

Traffic is incorrectly relayed to a local SPAN port instead of the SPAN destination port when the following conditions occur:

When the SPAN source and SPAN destination ports belong to ports [0-9] or both ports belong to ports [10-19]

The SPAN source port has a QoS policy-map attached and SPAN traffic matches that policy-map except for class-default.

Using ports [0-9] as SPAN source and [10-19] as SPAN destination or vice versa to avoid the above mentioned limitations.

You cannot use Gi|Te x/0/1 as a SPAN source port when the diagnostic test TestMacNotification is enabled.


So what you see reflects a known limitation.

netflow may be a way to monitor traffic

>> Sampled Netflow


Hope to help


Community Member

Re: Cisco 7606 and ES20 span port problem

It looks like it's on L2 ports  (trunk Dot1Q mode) so the flow-sampler can't capture the L2 traffic, it' works only on L3 ports (neither with MPLS packets)

Any idea ?

CreatePlease to create content