Data captured duing Span session

dvlewis · ‎03-12-2008

I am looking at QoS issue on a cat 4500 (IOS). I have a span session set up to capture traffic (using Wireshark).

I configured the span session to only capure rx traffic.

Are the packets I captured un-changed by the switch before I see them in my capture? More specifically, am I seeing the original TOS marking on the packet or what the switch might have remarked it to.

Thanks.

Jon Marshall · ‎03-12-2008

Hi

From 4500 configuration guide

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Packets that are modified because of routing are copied without modification for Rx SPAN; that is, the original packet is copied. Packets that are modified because of quality of service (QoS)-for example, modified Differentiated Services Code Point (DSCP)-are copied with modification for Rx SPAN.

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Full link:

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.1/20ew/configuration/guide/span.html

HTH

Jon