How can I stop "discard oversize frame" errors?

[Chuck Swiger]

Bryan Albright wrote:
> On 09/01/05 at 11:08AM, Chuck Swiger wrote:
>>>fxp0: discard oversize frame (ether type 800 flags 3 len 1573 > max 1514)
>>>fxp0: discard oversize frame (ether type 800 flags 3 len 1533 > max 1514)
>>>fxp0: discard oversize frame (ether type 5555 flags 3 len 1520 > max 1514)
>>>fxp0: discard oversize frame (ether type 800 flags 3 len 1564 > max 1514)
>>>
>>>I have 2 NICs in my machine, both intel etherexpress pro:
>>
>>Try setting an mtu of 1450 or so.  You can add that to the ifconfig lines 
>>in /etc/rc.conf, or run "ifconfig fxp0 mtu 1400" directly.
>
> I've tried to do that, but the fxp cards do not seem to allow
> modifying the mtu settings.  It does have the capability of modifying
> the vlanmtu, but I don't know if this will affect/help this issue.

Of course, it may be some other machine on your network which is generating 
those oversize packets, or someone may be using some form of encapsulation 
(PPTP?) which is pushing the frame size above the limit.

tcpdump would help...

-- 
-Chuck

PS: Oh, BTW, the fxp cards absolutely let you change the mtu?  What does 
ifconfig say...?