We used to see this when we had some MTU issue's
The problem was mainly servers and networks that were blocking ICMP,
they blocked more than just ICMP echo so the correct MTU size could not
be discovered (microsoft.com was a classic example). This issue would
also affect email uploads if the mail contained a attachment or a lot of
replys.
The main problem was we had 100mb links to the main L2TP suppliers and
the customers connected via PPPoA which reduced the available MTU size.
Once we upgraded all L2TP links with gig links the problem mostly went
away, mind you we still set the MTU to be lower (1460) on the virtual
template to get around most MTU problems. The issue gets worse when
customers start using VPN's.
It took many hours of fun to debug this and to provide a working
solution.
Wayne
On Sun, 2007-08-12 at 16:17 +0100, Rob Malpass wrote:
> ----- Original Message -----
> From: "Tim" <xendistar@???>
> To: "Hampshire LUG Discussion List" <hampshire@???>
> Sent: Saturday, August 11, 2007 10:21 PM
> Subject: Re: [Hampshire] [OT] Network issue - how to describe
>
>
> On Sat August 11 2007 22:09, Rob Malpass wrote:
> > Hi all
> >
> > I'm experiencing a problem with my ISP - and I need to know the technical
> > description of the fault in the hope that I get someone knowledgeable at
> > customer service (a pipe dream most likely but nonetheless).
> >
> > Symptom: Head for any website and I get a "Internet explorer cannot
> > display the page". Key in the same address again or hit f5 and hey
> > presto
> > - up comes the page.
> >
> > I'm in the position of being able to route traffic through another router
> > connected to Virgin and no such problems. Having done the usual things
> > of
> > rebooting routers, deleting temporary files etc, the problem only persists
> > with Orange.
> >
> > Is this DNS? If not, what's the most likely cause? I don't know why it
> > takes two attempts to get anywhere - and it doesn't happen with all
> > website
> > - just some.
> >
> > Cheers
> > Rob
>
> Try entering the IP address for a particular site in the address bar, does
> it
> load straight away or does it require a F5??
>
> Have you tried changing the dns IP's on the router that is causing the
> problem??
>
> Just a couple of quick thoughts?
>
> Tim
>
> >>>
>
> Bizarrely, about 5 minutes after posting, I received a message from
> OrangeProblems.co.uk and having followed a few links, I was told to change
> an "MTU" setting in the router which has fixed things nicely.
>
> Interesting that it had been working fine on the other MTU setting for
> around 5 years.
>
> Cheers
> Rob
>
>
>
--
Regards
Wayne Lee
Technical Manager
Link Connect Services ltd
Moor Park House
Moor Park Lane
Farnham
Surrey
Tel :: 0870 7433100
FAX :: 0870 7433101
http://www.link-connect.com
MSN :: wayne.lee@???
