VLAN trunking and fragmentation

[Ingo Flaschberger]

Dear Giuilio,

> Sean Chittenden wrote:
>>> interface ethernet 1/g1
>>> switchport mode trunk
>>> switchport trunk allowed vlan add 10
>>> exit
>> 
>> I think this is an issue with default VLAN membership. 
>
> I don't think it's where the problem lies, otherwise even a simple ping
> wouldn't work. The problem here explicitly arises when packets are
> fragmented...

fragmentation?
I think, you use ethernet links, all have 1500byte max packet size,
you have 1500byte packet size also comfigured at the vlan interface, so..
why do you think anything should start fragmenting?
(and tagged vlan frames are bigger than 1500byte at the "raw" ethernet 
link).

check for maximum mtu that can travel over the link.
(ping -s 1472  for 1500byte packet)

>>  switchport trunk encapsulation dot1q
>> 
> There's no such option, I believe it's implicit in the trunk mode...

and put the server back to back and remove the switch, just to be shure 
the switch is not the problem.

Kind regards,
 	Ingo Flaschberger