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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 21 Configuring SPAN and RSPAN Configuring RSPAN
•You shou ld crea te an RSPAN VLAN befo re configuring a n R SPAN sourc e or dest inat ion s ession .
•If you enable VT P and VTP pruning, RSPAN traff i c is pruned in the trunks to pr e ven t the unw anted
floodi ng of RSPAN traffic across the net work for VL AN-IDs th at are l ower than 1005.

Creating an RSPAN Session

First crea te an RSPAN VLAN that does not exist for the RSPAN session in an y of th e switc hes that will
participate in RSPAN. With VTP enabled in the network, you can create the RSPAN VLAN in one
switch, and VTP propagates it to the other switches in the VTP domain for VLAN-IDs that are lower
than 1 005 .
Use VTP prunin g to get efficient flow of RSPAN traff ic, o r man ually delete th e RSPAN VLAN from a ll
trunks th at do not need to carr y the RSPAN traffic.
After creating the RSPAN VLAN, begin in privileged EXEC mode, and follow these steps to start an
RSPAN source session and to specify the source (monitored) ports and the destination RSPAN VLAN.
Command Purpose
Step 1 configure terminal Enter globa l configurati on mode.
Step 2 no monitor session {session_number | all |
local | remote}Clear any existing RSPAN configuration for the session.
For session_number, specify 1 or 2.
Specify all to remove all RSPAN sessions, local to remove all local
sessions, or remote to remove all remote SPAN sessions.
Step 3 monitor s ession session_n umber source
interface interface-id [, | -] [both | rx | tx]Speci fy the RSPAN session an d the sourc e port (monit ored port ).
For session_number, specify 1 or 2.
For interface-id, specify the source port to monitor. Valid interfaces
includ e physical int erfaces and por t-channe l logica l interfac es
(port-channel port-channel-number).
(Optional) [, | -] Spec ify a se ries or ra nge of i nt erf aces . En ter a space
after the c om ma ; e nter a s pa ce b ef ore and a ft er th e hyph en.
(Optional) Specify the direction of traffic to monitor. If you do not
specify a traffic d irection, the source interface sends both sent and
received tra ffic. On ly r ec e ived (rx) traffic can be monitored on
additional source ports.
•both—Moni tor b oth re ceived and sent tra ffic.
•rx—M oni tor rece ived traffic.
•tx—Monitor sent traffic.
Step 4 monitor s ession session_number
destination remote vlan vlan-id
reflector-port interface
Specify the RSPAN session, the destination remote VLAN, and the
reflec tor po rt.
For session_number, enter 1 or 2.
For vlan-id, specify the R SPAN VLAN to carry the moni tored traf f ic
to the destination port.
For interface, speci fy the interf ac e th at wil l flo o d the R SPAN traffic
onto the RSPAN VLAN.
Step 5 end Return to privileged EXEC mode.