This tech-recipe provides instructions for SPAN and RSPAN configuration. SPAN mirrors a port within the same switch, while RSPAN mirrors a port in a remote switch.
In CatOS, use the following syntax to establish a SPAN session:
set span (source port|source vlan) (destination port) (rx|tx|both)
Note the following example which will mirror all traffic from 3/1 to 3/2:
set span 3/1 3/2 both
Older workgroup switches follow this syntax to mirror traffic from 1/2 to 1/5.:interface fastethernet 1/5
port monitor 1/2 both
Newer IOS on workgroup switches use the monitor session command:interface fastethernet 1/5
monitor session 1 source interface 1/2 both
ormonitor session 1 source vlan 100 both
For RSPAN, first configure an RSPAN VLAN:set vlan 200 rspan
This VLAN will be distributed over VTP, I would presume.
Then, configure the RSPAN source on the remote switch:set rspan source 3/1 both
orset rspan source 100 both
Finally, a destination must be defined:set rspan destination 4/5
