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New Member

RSPAN with Cat2950 Switches

Good day,

I'm trying to create a RSPAN session with 2 Catalyst 2950 switches but it doesn't work (no packets shown by the network analyzer).

I don't know what I'm doing wrong. Does anybody see any mistake in my configuration?

- all ports in VLAN 1, except of Fa0/48 (Trunk to neighbor device)

Switch 1:

vlan 99

name Monitor-VLAN


interface FastEthernet0/24

description switch-2 Fa 0/48

switchport mode trunk

switchport nonegotiate

monitor session 1 source interface Fa0/1 rx

! Notebook for testing connected to Fa0/1

monitor session 1 destination remote vlan 99 reflector-port Fa0/23

Switch 2:

vlan 99

name Monitor-VLAN


interface FastEthernet0/24

description switch-1 Fa 0/48

switchport mode trunk

switchport nonegotiate

monitor session 1 destination interface Fa0/1

! NW-Analyzer connected to Fa0/1

monitor session 1 source remote vlan 99




Re: RSPAN with Cat2950 Switches


Could you please let me know how many trunk links are used between the switches..

You said Fa0/48 is the trunk link but your config suggests you are using fa 0/24 for trunk link as well.

Also..Do you have any other switch linke 3550,3560 that you can use as an intermediate switch for RSPAN.

What do you see in your Show vlan. Paste the output under vlan 99.


-amit singh

New Member

Re: RSPAN with Cat2950 Switches

Thank you for the quick response.

You're right - the trunks are not on Fa0/48 (both switches have only 24 ports) but on Fa0/24.

It's just a test with only those 2 switches, connected to each other (only) via Fa0/24.

Here is the output of the show vlan command:

Switch#s vlan id 99

VLAN Name Status Ports

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

99 Monitor-VLAN active Fa0/24

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2

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

99 enet 100099 1500 - - - - - 0 0




Primary Secondary Type Ports

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



Re: RSPAN with Cat2950 Switches

Well, Rolf the configuration is ablsoutely fine and seems to be a hardware limitaion only.

Please make sure that you dont have any other SPAN or RSAPN session configured on either of the switch. I see that you are montiroing the traffic only in one direction which doesnot apply to the RSPAN limitaion either.

Please let me know the IOS version you are using. Paste an output of show version.


-amit singh

New Member

Re: RSPAN with Cat2950 Switches


sorry - I didn’t see your response yesterday.

Here’s the output of show version:

Switch#s vers

Cisco Internetwork Operating System Software

IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA4a, RELEASE SOFTWARE


Copyright (c) 1986-2005 by cisco Systems, Inc.

Compiled Fri 16-Sep-05 10:46 by yenanh

Image text-base: 0x80010000, data-base: 0x80562000

ROM: Bootstrap program is C2950 boot loader

Switch uptime is 45 minutes

System returned to ROM by power-on

System image file is "flash:/c2950-i6q4l2-mz.121-22.EA4a.bin"

cisco WS-C2950-24 (RC32300) processor (revision R0) with 21039K bytes of memory.

Processor board ID xxxxx

Last reset from system-reset

Running Standard Image

24 FastEthernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address: xxxx

Motherboard assembly number: xxxx

Power supply part number: xxxx

Motherboard serial number: xxxx

Power supply serial number: xxxx

Model revision number: R0

Motherboard revision number: A0

Model number: WS-C2950-24

System serial number: xxxx

Configuration register is 0xF

I studied the ‘Configuring SPAN and RSPAN’ (Chapter 21 of Catalyst 2950 Desktop Switch Configuration Guide) again and found as a Configuration Guideline:

..., you must have EI installed on your switch.

I wonder what ‘EI’ means?



New Member

Re: RSPAN with Cat2950 Switches

Hello Rolf,

have you found a solution ?

I have got exactly the same problem.

I insert a new question, why have you inserted the fa0/23 for reflector port ?

best regards.

New Member

Re: RSPAN with Cat2950 Switches

Unfortunately I didn't find a solution with my test equipment but I tried the same configuration with a Cat4006 and a Cat3550 in our productive Network and it works fine.

I think it's a platform issue. And unfortunately I still don't know what 'EI' means. Maybe enhanced image? Doesn't sound plausible but I've no better idea.

Re: RSPAN with Cat2950 Switches


You are rite in pointing out EI as Enhanced Image would suggest to check this link for more info on that.


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