[VLAN] Gigabit and MTU > 1500

[rossnick-lists at cybercat.ca (Nicolas Ross)]

> In practice I don't think this will give you a lot performance-wise. The
> most of the world is at 1500 bytes so the MTU in use at most of the time
> would probably be 1500.
>
> This could work in a scenario where you are doing large transaction
> where window scaling max out to 9000 bytes.
>

In fact, it's performance inside the vlan I'm seeking, not performance to 
the outside. To the outside, I'll be at 1500.

>> But we have some other vlan that needs to stay at 1500. If I specify in 
>> the
>> ifconfig command the MTU, will this work as I expected ?
>
> yes
>
>> Also, is there a way to specify de MTU in the ifcfg-vlanxxx file in
>> sysconfig/network-scripts ?
>
> at least in Fedora, yes :)

I tried adding MTU=nnn in ifcfg-vlan5 for exemple, and it didn't do what I 
want. I add to add

if [ -n "${MTU}" ]; then
   ip link set ${DEVICE} mtu ${MTU}
fi

to /etc/sysconfig/network-scripts/ifup-vlan, before the ifconfig and it 
worked.

Thanks,