Cisco Support Community
Community Member

2950 span sessions

I would like to know if a 2950 switch supports a span session from a single source interface to two destination interfaces. Switch is running image version 12.1(22)EA1. Thanks Mark


Re: 2950 span sessions

No you can only have 1 destination port on a 2950 .

Community Member

Re: 2950 span sessions

Thanks. So if I understand you correctly no 2950 switch supports a SPAN session from a single source port to more than one destination port?

Re: 2950 span sessions

Yes, looks like you can.

The output below is from a 2924 switch running IOS version 12.0(5.1)XP.

SW2-2924XL#config t

Enter configuration commands, one per line. End with CNTL/Z.

SW2-2924XL(config)#int f0/1

SW2-2924XL(config-if)#port ?

block Forwarding of unknown uni/multi cast addresses

group Place this interface in a port group

monitor Monitor another interface

network Configure an interface to be a network port

security Configure an interface to be a secure port

storm-control Configure broadcast storm control parameters

SW2-2924XL(config-if)#port monitor f0/3

SW2-2924XL(config-if)#int f0/2

SW2-2924XL(config-if)#port monitor f0/3



05:57:14: %SYS-5-CONFIG_I: Configured from console by console

SW2-2924XL#show port monitor

Monitor Port Port Being Monitored

--------------------- ---------------------

FastEthernet0/1 FastEthernet0/3

FastEthernet0/2 FastEthernet0/3

Hope that helps.


Cisco Employee

Re: 2950 span sessions

Hi Sundar,

You are using a 2900XL switch, not a 2950 switch.

Per the 2950 documentation, you can only have one destination port:



*Please rate helpful posts.


Re: 2950 span sessions

Per cisco docs on span for the 2950.

SPAN Configuration Guidelines

Follow these guidelines when configuring SPAN:

* SPAN sessions can coexist with RSPAN sessions within the limits described in the "SPAN and RSPAN Session Limits" section.

* The destination port cannot be a source port; a source port cannot be a destination port.

* You can have only one destination port.

* An EtherChannel port can be a SPAN source port; it cannot be a SPAN destination port.

* For SPAN source ports, you can monitor sent and received traffic for a single port or for a series or range of ports.

* When you configure a switch port as a SPAN destination port, it is no longer a normal switch port; only monitored traffic passes through the SPAN destination port.

* You can configure a disabled port to be a source or destination port, but the SPAN function does not start until the destination port and at least one source port is enabled.

* A SPAN destination port never participates in any VLAN spanning tree. SPAN does include BPDUs in the monitored traffic, so any spanning-tree BPDUs received on the SPAN destination port for a SPAN session were copied from the SPAN source ports.

* When SPAN is enabled, configuration changes have these results:


o If you change the VLAN configuration of a destination port, the change is not effective until SPAN is disabled.

o If you disable all source ports or the destination port, the SPAN function stops until both a source and the destination port are enabled.

CreatePlease to create content