2950 LACP interesing question

Chris Knight

I am reading the BCMSN cisco press book and it states that 2950 switches are not capable of running pagp AND lacp.

Here is the output from my switch:
Switch2#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(14)EA1a, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2003 by cisco Systems, Inc.
Compiled Tue 02-Sep-03 03:33 by antonino
Image text-base: 0x80010000, data-base: 0x805C0000

ROM: Bootstrap program is CALHOUN boot loader

Switch2 uptime is 1 week, 5 hours, 3 minutes
System returned to ROM by power-on
System image file is "flash:/c2950-i6q4l2-mz.121-14.EA1a.bin"

cisco WS-C2950-24 (RC32300) processor (revision B0) with 20710K bytes of memory.
Processor board ID FAB0551Q06Q
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: 00:08:7C:80:5A:40
Motherboard assembly number: 73-5781-08
Motherboard serial number: FAB05507FUM

Here is my channel-protocol output:
Switch2#
Switch2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch2(config)#int fa 0/2
Switch2(config-if)#spa
Switch2(config-if)#channe
Switch2(config-if)#channel-pr
Switch2(config-if)#channel-protocol ?
lacp Prepare interface for LACP protocol
pagp Prepare interface for PAgP protocol

Switch2(config-if)#channel-protocol
Switch2#

Does anyone know why both are showing up as an option? Is it due to the revision in my IOS version?

mikej412

It may have gotten the PAgP and LACP capability in 12.1(6) -- but the Feature Navigator is always the best place to check to be sure.

I think prior to that it could respond to PAgP requests, but not initiate..... but I'm not sure if that was just the LRE versions.

Chris Knight

Thanks

tech-airman

Chris Knight,

Chris Knight wrote:

I am reading the BCMSN cisco press book and it states that 2950 switches are not capable of running pagp AND lacp.

That is correct. Just like ISL is Cisco Proprietary and 802.1q is vendor neutral, PAgP is Cisco Proprietary and LACP is vendor neutral.

Chris Knight wrote:

Here is the output from my switch:
Switch2#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(14)EA1a, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2003 by cisco Systems, Inc.
Compiled Tue 02-Sep-03 03:33 by antonino
Image text-base: 0x80010000, data-base: 0x805C0000

ROM: Bootstrap program is CALHOUN boot loader

Switch2 uptime is 1 week, 5 hours, 3 minutes
System returned to ROM by power-on
System image file is "flash:/c2950-i6q4l2-mz.121-14.EA1a.bin"

cisco WS-C2950-24 (RC32300) processor (revision B0) with 20710K bytes of memory.
Processor board ID FAB0551Q06Q
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: 00:08:7C:80:5A:40
Motherboard assembly number: 73-5781-08
Motherboard serial number: FAB05507FUM

Here is my channel-protocol output:
Switch2#
Switch2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Switch2(config)#int fa 0/2
Switch2(config-if)#spa
Switch2(config-if)#channe
Switch2(config-if)#channel-pr
Switch2(config-if)#channel-protocol ?
lacp Prepare interface for LACP protocol
pagp Prepare interface for PAgP protocol

Switch2(config-if)#channel-protocol
Switch2#

Does anyone know why both are showing up as an option? Is it due to the revision in my IOS version?

What the book is saying is that over a single link, the above configuration is for lacp OR pagp on the interface fastethernet 0/2 and NOT lacp AND pagp. In other words, it's an either/or NOT both AT THE SAME TIME.

I hope this helps.