Span with Filtering option

[sameermunj]

Hi team  i want to configure span on Catalyst 3750G (with ip services software 12.2.55 se4) with filtering option.basically single port on the switch will be configured as span port and destination traffic on this port to be filtered to get only layer 4 port based traffic (e.g. TCP or UDP)..So in summary instead of getting all the traffic on this span port,we should get only udp traffic.  is it possible to attach any access list matching this tcp/udp ports so this monitor session command..  if its possible,kindly send the related documentation with SW/HW prerequisite if any....  Regards Sameer

[Gabriel Hill · Accepted solution]

Hello Sameermunj,

FSPAN/FRSPAN is what you would need to do. I am unsure if it's supported on the 3750G but you could give it a try.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3750x_3560x/software/release/12.2_55_se/configuration/guide/swspan.html#wp1334910

[sameermunj]

HI Gabriel  Thanks for the quick reply...  i will try to use this command on 3750G (12.2.55 SE4 ) as well as on 12.2.55.SE7 the latest  release for this platform...  so as per the document shared by you with Fspan,i can create an access list matching my required TCP/UDP ports and then can attach the corresponding access group to monitor session so that Network Analyzer connected on destination port will receive only required TCP/UDP traffic instead of getting all source traffic...please correct me if i am wrong..  Sameer

[Gabriel Hill]

Yes you are correct. The ACL matches the traffic you want to monitor, anything not matched by the ACL is dropped.

[sameermunj]

Hi Gabriel  Does it supported on Cat 45xx Series..

[sameermunj]

Hi  i have checked and found that its supported on 12.2.2o EW release..