Re: MTU of the Internet?

["Kevin A. Smith" <kevin () ascend com>]

At 12:18 PM 2/5/98 -0600, Phil Howard wrote:
> Marc Slemko writes...
>
> > First, I _really_ doubt the web server set the DF bit.  It is almost
> > certainly the OS, probably trying to do path MTU discovery.
> >
> > If there is a smaller MTU in the middle, and someone is filtering ICMP
> > can't fragment errors then yes, you will have trouble with PTMU discovery.
> > The fix is to not blindly filter ICMP.  Increasing the client MTU won't
> > fix this.
>
> Agreed that one should not blindly filter ICMP.  However not all filter
> tests don't support discriminating individual ICMP types.  Ascend is one
> example.

Why not? You have the options to use IP filters which are fairly limited,
or generic filters where you can specify more details of the filter.


Kevin