Setting MTU on Catalyst 2950

[jason.chin]

Greetings, Im seeking some assistance with increasing MTU on a Catalyst 2950 switch. I want to be able to pass packets of 1522 max. I have accomplished this in the past using a Catalyst 2912 Switch with commands: conf term, int fa0/port # and mtu 1522 this does not seem to work on the Catalyst 2950. Can you assist me in accomplishing this with the Catalyst 2950? Thanking you in advance.

Jason Chin

[Prashanth Krishnappa]

You need to increase MTU usingsystem mtu global configuration command

http://cio.cisco.com/univercd/cc/td/doc/product/lan/cat2950/1219ea1/cli/cli2.htm#xtocid83

There was a bug filed for similar issue on 3550. The bug ID is CSCdw07890 and is fixed in 12.1(9)EA1

[jason.chin]

HI, thanks for all the help so far. I tried running the system mtu 1522 command as suggested in the documentation at the url you posted but my switch does not recognise "system" as a valid command.

catalyst-1>enable

Password:

catalyst-1#conf term

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

catalyst-1(config)#system mtu 1533

^

% Invalid input detected at '^' marker.

I believe the command was first introduced with Release 12.1(6)EA2 but im running Version 12.0(5.3)WC(1).

Cisco Internetwork Operating System Software

IOS (tm) C2950 Software (C2950-C3H2S-M), Version 12.0(5.3)WC(1)

-Jason

[Prashanth Krishnappa]

That is correct. You need to be running atleast 12.1(6)EA2 but I suggest 12.1(9)EA1c

[jason.chin]

I downloaded and TFTPed c2950-i6q4l2-tar.121-9.EA1.tar into my switch. All i need to do now is a reboot, i will do it later when usage drops. Thanks again for the help.

[jason.chin]

Hi, im still having problems setting the MTU on my Catalyst 2950, I upgraded the IOS to Version 12.1(9)EA1. So the "system" command is now recognised but i cant alter the MTU value. The MTU range is 1500 - 1500.

catalyst-1#conf term

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

catalyst-1(config)#system mtu 1528

^

% Invalid input detected at '^' marker.

catalyst-1(config)#system mtu ?

<1500-1500> MTU size in bytes

catalyst-1(config)#

Any suggestions?

-Jason

[Prashanth Krishnappa]

Jason

Looks like you have the 2950C switch. Only 2950G's support the system mtu command

http://www.cisco.com/warp/customer/cc/pd/si/casi/ca2950/prodlit/c29ie_ds.htm

Here is the output from a 2950G switch

2950G-48-3A#conf terminal

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

2950G-48-3A(config)#system mtu 1528

2950G-48-3A(config)#end

2950G-48-3A#sh sy

1w2d: %SYS-5-CONFIG_I: Configured from console by consoles

2950G-48-3A#sh system mtu

System MTU size is 1528 bytes