system mtu reload required?

[markgbrs]

Hi all,

I would need to change the MTU to 1504 on a C3650-48TS to support Q-in-Q, but it's not clear to me whether a reload is required in this case.

In this document, there is no mention of a reload;

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/software/release/3se/int_hw_components/configuration_guide/b_int_3se_3650_cg/b_int_3se_3650_cg_chapter_0110.html

In this one however, there is:

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3650/software/release/37e/consolidated_guide/b_37e_consolidated_3650_cg/configuring_system_mtu.pdf

Unfortunately, I don't have a spare unit available or I would simply test it, so if anyone can confirm this, would be appreciated.

KR,

Mark

[Georg Pauwen]

Hello,

whatever shows up with 'show system mtu' is what is currently operational. For interfaces, MTU changes don't need a reload, for the system, I think it is.

After you change the size, what is the output of 'show system mtu' ?

[markgbrs]

Hi,

on a C3750 running 'normal' IOS, a reload is required which is seen by the command you suggested:

Switch#show system mtu

System MTU size is 1500 bytes
On next reload, System MTU will be 1504 bytes

Unfortunately I am not permitted to test this on the IOS XE as it is in production, so the question is whether this is still the case with IOS XE?

Reading the documentation about implementing Q-in-Q, it would seem the system mtu needs to be changed and the MTU cannot be changed on a per-interface level, but do correct me if I'm wrong.

KR,

Mark