web site does not load on client PC but is fine on gateway

Hello -

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. Any ideas as to why this would happen and
how to remedy it?

Thanks a lot.
Brian

Brian wrote:
> Hello -
>
> 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. Any ideas as to why this would happen and
> how to remedy it?
>
> Thanks a lot.
> Brian

Dear Brian,
since you didn't provide us with enough facts we'll try it this
way for the beginning: Does your problem affect all sites or only
certain sites?
You might need to change the MTU value of your network settings...
I've heard from some people having the same problem and solved it
that way. Try to search google for how to change MTU.
If this problem happens with all sites you better check
the connection to the linux box first!
Do you get a response with a ping linux_box from the win pc's?
Check route to the internet by issuing a ping from the win_pc's to
lets say boston.com: ping 66.150.192.21 (yeah, it's boston.com)
If you get a response then there is an error with your dns.
Alternatively you might check it with nslookup boston.com.
If you haven't installed dns you can't resolve names.
Another possible cause is that you haven't setup the routes correctly.
Cheers
Monzai :-)


If you have a lot of web-frontends to manage your network and configure
your services sooner or later you will need a tool like Monzai!
Since it is so hard to describe Monzai, please have a look at
http://www.monzai.com/

Thanks Monzai -

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.

Ill look into chaning the MTU value. Thanks a lot for your help on
this.

Brian


"monzai.com" <(E-Mail Removed)> wrote in message news:<(E-Mail Removed)>...
> Brian wrote:
> > Hello -
> >
> > 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. Any ideas as to why this would happen and
> > how to remedy it?
> >
> > Thanks a lot.
> > Brian
>
> Dear Brian,
> since you didn't provide us with enough facts we'll try it this
> way for the beginning: Does your problem affect all sites or only
> certain sites?
> You might need to change the MTU value of your network settings...
> I've heard from some people having the same problem and solved it
> that way. Try to search google for how to change MTU.
> If this problem happens with all sites you better check
> the connection to the linux box first!
> Do you get a response with a ping linux_box from the win pc's?
> Check route to the internet by issuing a ping from the win_pc's to
> lets say boston.com: ping 66.150.192.21 (yeah, it's boston.com)
> If you get a response then there is an error with your dns.
> Alternatively you might check it with nslookup boston.com.
> If you haven't installed dns you can't resolve names.
> Another possible cause is that you haven't setup the routes correctly.
> Cheers
> Monzai :-)
>
>
> If you have a lot of web-frontends to manage your network and configure
> your services sooner or later you will need a tool like Monzai!
> Since it is so hard to describe Monzai, please have a look at
> http://www.monzai.com/

Dear Brian,

Have you setup either the following

1. a bind service at gateway, and all Window PCs has DNS setup to this
gateway, or
2. all Window PCs has DNS setup to DNS server of your ISP

K.K.Lai

"Brian" <(E-Mail Removed)> ???
news:(E-Mail Removed) m ???...
> Hello -
>
> 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. Any ideas as to why this would happen and
> how to remedy it?
>
> Thanks a lot.
> 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.

That's because you've blocked ICMP messages, which are part of Path MTU
Discovery. You should either allow "fragmentation-needed" type ICMPs,
or reduce MTU on internal PC (if it has Windows - check MS KB article#158474).
Set MTU to 1400.

--
andrei