[c-nsp] mtu issues on 3750

[Harald Michl]

Hi,

Tassos Chatzithomaoglou wrote:

> There is no support for such (mtu per interface) configuration....

I can't confirm this. We explicitly use 12.2(25)SE software for our 
3750s, where this feature exists. We use it on boxes we have to do 
Layer3, but also have to transport dot1q-tunnels.
Since 12.2(25)SEA the interface command is gone... Even the 
interface-command "ip mty xy" isn't accepted by the parser.


regards & HTH,
Harald

Router#show version
Cisco IOS Software, C3750 Software (C3750-I5K91-M), Version 12.2(25)SE, 
RELEASE SOFTWARE (fc)
Copyright (c) 1986-2004 by Cisco Systems, Inc.
Compiled Wed 10-Nov-04 23:30 by yenanh


Router#sho system mtu

System MTU size is 1546 bytes
System Jumbo MTU size is 1546 bytes


interface GigabitEthernet1/0/6
  no switchport
  ip address 192.168.1.1 255.255.255.0
  ip mtu 1500


Router#sho int g1/0/6
GigabitEthernet1/0/6 is down, line protocol is down (notconnect)
   Hardware is Gigabit Ethernet, address is 000d.edbb.acc1 (bia 
000d.edbb.acc1)
   Internet address is 192.168.1.1/24
   MTU 1546 bytes, BW 10000 Kbit, DLY 1000 usec,
      reliability 255/255, txload 1/255, rxload 1/255
[snip]

Router#sho ip int g1/0/6
GigabitEthernet1/0/6 is down, line protocol is down
   Internet address is 192.168.1.1/24
   Broadcast address is 255.255.255.255
   Address determined by setup command
   MTU is 1500 bytes
   Helper address is not set
[snip]


The same works on vlan interfaces as well:

interface Vlan99
  ip address 192.168.2.1 255.255.255.0
  ip mtu 1500



-- 
   Harald Michl                   <michl at cc.univie.ac.at>
   Vienna University Computer Center - ACOnet - VIX
   Universitaetsstrasse 7, A-1010 Vienna, Austria, Europe
   Tel: ++43 1 4277 - 14078 (Fax: - 9140)     HM3550-RIPE