Re: wi problem with message > 7400 bytes

Daniel Eischen wrote:

> Greetings,
> 
> I'm having a problem receiving UDP messages over a wi interface:
> 
> wi1: <Dell TrueMobile 1150 Series PC Card> at port 0x180-0x1bf irq 11 function 0 config 1 on pccard0
> wi1: 802.11 address: 00:02:2d:4a:d8:7d
> wi1: using Lucent Technologies, WaveLAN/IEEE
> wi1: Lucent Firmware: Station (6.10.1)
> wi1: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
> 
> (wi0 is also a 'Dell TrueMobile 1150 Series PC Card' in
>  a mini-PCI card, but hangs the system when you try and
>  configure it -- so it obviously isn't configured in this
>  set up.)
> 
> I have a small program that does a trivial UDP test:
> 
>   http://people.freebsd.org/~deischen/udptest.c
> 
> My results show that:
> 
>   o Receiving large (> 7400 bytes) messages does not work.
> 
>   o Sending large messages works.
> 
>   o Sending & receiving large messages over a wired
>     interface (dc, fxp, etc) works.
> 
> Am I suppose to be able to receive UDP messages larger
> than 7400 bytes over the air?

Could you post a tcpdump for each case? I wonder if this is related to a 
fragmentation issue I've seen in the past.

Thanks,
Lars
-- 
Lars Eggert <larse_at_isi.edu>           USC Information Sciences Institute