RSPAN across sites ?

[ajenks]

I need to configure port spanning for call recording across multiple sites, with "monitored ports" (at remote sites) having a destination on a different switch at a different (central) site. I understand the basic concepts of rspan, but the configuration examples show switches linked with a trunk port to carry the rspan VLAN. In the instance where these sites are connected via a layer 3 routed network, how can I get the spanned traffic across sites ? I have no trunk between the switches, can I create one in this scenario ?

Any help would be greatly appreciated.

[Jerry Ye]

Without knowing what kind of hardware are in between, I can only recommend you to read up ERSPAN.

HTH,

jerry

[Adam Casella]

Hey Ajenks,

Unfortunately, RSPAN will not function across layer 3 interfaces and can only be used within the same layer 2 broadcast domain.

The only SPAN that would work in this case is ERSPAN, which is only supported on the 6500 and uses GRE between the source and destination.  See the link below:

http://cco.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/span.html#wp1059482

Unfortunately, since it unlikely that you have a 6500 at each remote site, it is not possible for RSPAN to accomplish this task.

Thanks,

Adam