Configuring VLAN Filtering for RSPAN on Access Switches with an Intermediate Switch

The following example configures VLAN-filtered mirror traffic that passes through intermediate switches to its destination.

VLAN Filtering for RSPAN with Intermediate Access Switches

  1. Configure Access Switch Router 1.
  2. Configure the RSPAN VLAN and VLAN ID (VLAN 191 in the example).
    device# configure terminal
device(config)# rspan-vlan 191
device(config-rspan-vlan-191)# tagged ethernet 1/2/1
device(config-rspan-vlan-191)# rspan destination ethernet 1/2/1
device(config-rspan-vlan-191)# rspan source monitor-in ethernet 1/1/1 ethernet 2/1/1
device(config-rspan-vlan-191)# exit
  3. Configure the mirror filter to filter VLANs 100 through 108.
    device(config)# mirror-filter source vlan 100 to 108
device(config)# exit
  4. (Optional) Verify the VLAN memberships for both of the monitored ports.
    device# show vlan brief ethernet 1/1/1
Port 1/1/1 is a member of 11 VLANs
VLANs 100 to 110 
Untagged VLAN   :
Tagged   VLANs  : 100 to 110 

device# show vlan brief ethernet 2/1/1 
Port 2/1/1 is a member of 10 VLANs
VLANs 3000 to 3009 
Untagged VLAN   :
Tagged   VLANs  : 3000 to 3009
  5. Configure VLAN memberships for the monitored ports if necessary.
  6. Configure Access Switch Router 2.
  7. Configure the RSPAN VLAN and VLAN ID (VLAN 197 in the example).
    device# configure terminal
device(config)# rspan-vlan 197
device(config-rspan-vlan-197)# tagged ethernet 2/2/1
device(config-rspan-vlan-197)# rspan destination ethernet 2/2/1
device(config-rspan-vlan-197)# rspan source monitor-in ethernet 1/1/2 ethernet 2/1/2
device(config-rspan-vlan-197)# exit
  8. Configure the mirror filter to filter VLANs 100 through 108.
    device(config)# mirror-filter source vlan 100 to 108
device(config)# exit
  9. (Optional) Verify the VLAN memberships for both of the monitored ports.
    device# show vlan brief ethernet 1/1/2
Port 1/1/2 is a member of 11 VLANs
VLANs 100 to 110 
Untagged VLAN   :
Tagged   VLANs  : 100 to 110 

device# show vlan brief ethernet 2/1/2
Port 2/1/2 is a member of 10 VLANs
VLANs 3000 to 3009 
Untagged VLAN   :
Tagged   VLANs  : 3000 to 3009
  10. Configure VLAN memberships for the monitored ports if necessary.
  11. Configure Intermediate Switch Router 3.
  12. Configure RSPAN transit VLANs as required on intermediate Router 3 (VLANs 191 and 197 in the example).

    The rspan-transit-vlan command creates a transit VLAN that forwards RSPAN mirrored traffic from access switches, and MAC learning is disabled on the VLAN.

    Note: The rspan-transit-vlan command is needed only in the following cases:
    • On intermediate switches where the user needs to configure multiple RSPAN transit VLANs , as it is not possible to configure multiple RSPAN VLANs on a switch
    • For topologies where the user does not want to enable MAC learning on transient VLANs for intermediate switches. 
    device# configure terminal
device(config)# rspan-transit-vlan 191
device(config-rspan-transit-vlan-191)# tagged ethernet 1/2/1 ethernet 1/1/19
device(config-rspan-transit-vlan-191)# exit
device(config)# rspan-transit-vlan 197
device(config-rspan-transit-vlan-197)# tagged ethernet 2/2/1 ethernet 1/1/19
device(config-rspan-transit-vlan-197)# end

The following example configures access Router 1 and Router 2 for RSPAN. Both Router 1 and Router 2 are configured to filter out mirrored traffic on VLANs 100 through 108. The example configures an intermediate Router 3 with the RSPAN transit VLANs that match the VLAN IDs configured for RSPAN on Router 1 and Router 2 (VLANs 191 and 197). 

device# configure terminal <-Configure R1 RSPAN
device(config)# rspan-vlan 191
device(config-rspan-vlan-191)# tagged ethernet 1/2/1
device(config-rspan-vlan-191)# rspan destination ethernet 1/2/1
device(config-rspan-vlan-191)# rspan source monitor-in ethernet 1/1/1 ethernet 2/1/1
device(config-rspan-vlan-191)# exit

device(config)# mirror-filter source vlan 100 to 108 VLANs filtered (R1)
device(config)# exit

device# show vlan brief ethernet 1/1/1 <-Verify R1 VLANs
Port 1/1/1 is a member of 11 VLANs
VLANs 100 to 110 
Untagged VLAN   :
Tagged   VLANs  : 100 to 110 
device# show vlan brief ethernet 2/1/1 
Port 2/1/1 is a member of 10 VLANs
VLANs 3000 to 3009 
Untagged VLAN   :
Tagged   VLANs  : 3000 to 3009

device# configure terminal <-Configure R2 RSPAN
device(config)# rspan-vlan 197
device(config-rspan-vlan-197)# tagged ethernet 2/2/1
device(config-rspan-vlan-197)# rspan destination ethernet 2/2/1
device(config-rspan-vlan-197)# rspan source monitor-in ethernet 1/1/2 ethernet 2/1/2
device(config-rspan-vlan-197)# exit

device(config)# mirror-filter source vlan 100 to 108 <-VLANs filtered (R2)
device(config)# exit

device# show vlan brief ethernet 1/1/2 <-Verify R2 VLAN members
Port 1/1/2 is a member of 11 VLANs
VLANs 100 to 110 
Untagged VLAN   :
Tagged   VLANs  : 100 to 110 

device# show vlan brief ethernet 2/1/2
Port 2/1/2 is a member of 10 VLANs
VLANs 3000 to 3009 
Untagged VLAN   :
Tagged   VLANs  : 3000 to 3009

device# configure terminal <-Configure intermediate R3 VLANs
device(config)# rspan-transit-vlan 191
device(config-rspan-transit-vlan-191)# tagged ethernet 1/2/1 ethernet 1/1/19
device(config-rspan-transit-191)# exit
device(config)# rspan-transit-vlan 197
device(config-rspan-transit-vlan-197)# tagged ethernet 2/2/1 ethernet 1/1/19
device(config-rspan-transit-vlan-197)# end
Parent topic: Configuring VLAN-based filtering for SPAN or RSPAN