How can I stop "discard oversize frame" errors?

[Bryan Albright]

On 09/01/05 at 02:12PM, Chuck Swiger wrote:
> Greg Barniskis wrote:
> [ ... ]
> >Isn't this message being generated when the router sends a packet that 
> >exceeds fxp0's MTU, so... the solution is to tune the router's MTU, 
> >rather than fxp0? I am admittedly just guessing, but intuitively that 
> >seems right.
> 
> You want to tune the MTU of whatever is generating the oversize packets, 
> agreed.  The messages in syslog do not reveal the source of the oversize 
> packets, but "tcpdump -n greater 1520" should.
> 
> -- 
> -Chuck

I appreciate all the help, thanks!

Okay, I've tried running the above (tcpdump -ni fxp0 greater 1520) but I get
no output.

If I drop it down to 1510 (tcpdump -ni fxp0 greater 1510), I get
responses from everything sized 1452
(13:47:08.929873 IP 63.231.195.31.110 > <MY.PRIV.IP.CUT>.2984: . 17520:18980(1460) ack 1 win 58400)
and up.  (63.231.195.31 is the pop server my wife uses to check her
mail--  and note the length is at 1460, which I don't believe is enough
to generate the discard oversize frame errors)

However, I've even with the tcpdump running -- at any of the above
size levels, I get the "discard oversize frame" errors with a "len"
ranging from 1517 up to 2030.

*sigh*  Frustrating.

Thanks again!

Bryan

-- 
Never Play Leap Frog With A Unicorn.