problems viewing specific websites

Ive got a home network with a RH Linux box as a gateway/firewall with
several Windows PCs on the inside. Some sites (for example
http://www.boston.com) do not load on the internal PC, but it loads
fine on the Linux gateway.

I dont think it is an issue with the connection or DNS as I am able to
partially render the pages on these sites. A better description of
the problem would be that the page partially loads, but images and
other page elements are extremely slow to load, if at all.

I have surfed the same sites on the same windows PC but over a
different gateway (its a laptop, so I can bring it in to work and surf
fine). Therefore, I am pretty sure that it is a problem with the
gateway machine's configuration.

Thanks,Brian

Brian <(E-Mail Removed)> wrote:

> Ive got a home network with a RH Linux box as a gateway/firewall with
> several Windows PCs on the inside. Some sites (for example
> http://www.boston.com) do not load on the internal PC, but it loads
> fine on the Linux gateway.
>
> I dont think it is an issue with the connection or DNS as I am able to
> partially render the pages on these sites. A better description of
> the problem would be that the page partially loads, but images and
> other page elements are extremely slow to load, if at all.

This sounds like the typical MTU mismatch problem. MTU size on
internal interface set to 1500 bytes and on external interface
eg. 1492 bytes. This wouldn't be a problem if path MTU discovery
would work with all sites, however some admins disable/block the
ICMP protocol and this breaks the Path MTU Discovery.

The easiest is to check on the gateway the MTU size of the
external interface (eg 1492 bytes on ppp over ethernet) and
then configure the internal interfaces of all LAN clients
with the same MTU size.

Another solution is to disable Path MTU Discovery and have the
routers along the path fragment the packets.


Ciao, Horst
--
»When pings go wrong (It hurts me too)« E.Clapton/E.James/P.Tscharn