[Click] Stupid question/problem on SendTo

[Nicholas Weaver]

Self followup:  The broadcom chipset in the Dell system in question (a  
BCM5721) just doesn't support Jumbo frames....

So that is stuck with a 1500B MTU, and can't be configured higher.

Off to go buy a genuine Intel GigE card instead...


On Aug 21, 2009, at 9:03 AM, Nicholas Weaver wrote:

> I've got a stupid configuration thats adding VLAN tags to a packet  
> from a dummy interface and then sends it out:
>
> (userlevel, linux)
>
> A stripped down representation of the path in question:
>
> FromHost(dummy, 10.3.128.2/16) -> TagVLAN(164) -> Queue ->  
> ToDevice(eth1);
>
> Of course, now I have a problem with MTU packets on FromHost:
>
> 1496 byte (total size) ICMP packets work no problem...
>
> 1500 byte (MTU) ICMP packets don't get sent, with a:
> ToDevice(eth1) send: Message too long
>
> error.
>
> How do I convince ToDevice to send a full frame ethernet packet with  
> a VLAN tag?
>
> Thanks.
>