Hi Craig

I think the MTU/ICMP issue identified in the IDG article and by a couple of
other respondents is the source of the problem. My setup (XP, IE6) was
fully patched with default settings including a standard MTU of 1500.

It had got to the stage where I couldn't use the NBNZ internet banking site
for any transaction recently through Jetsart ADSL, but it would work fine
through a standard modem connection on the same computer.

So tonight I tried reducing my MTU size and guess what, the site started
working for transactions through Jetstart!

I haven't worked out the optimum MTU size yet, I was pretty brutal and cut
it in half to 750 initially, but I guess the GRE packet size of 1476 will
prove to be the functional limit.

If this really is the problem it seems that the banks can't really blame
people tweaking their TCP settings for the problem, rather it is their
policy of blocking ICMP messages.

I'm going to contact the NB and suggest they take a look at how many people
responded to my question as an indication that quite a few people are
experiencing this problem, far more than the banks seem to imply in their
responses in the article.

Thanks to everybody who replied. It looks like I've got a fix, but I think
the banks still have the problem..

Cheers

Andrew

----- Original Message -----
Subject: Re: Online Banking and ADSL problems?

> See::
>
> http://www.idg.net.nz/webhome.nsf/UNID/4AA2988B4A1835C5CC256BFF0014A6A8!
> opendocument
>
> (a more technical expanation from Cisco of the problem
> http://www.cisco.com/warp/public/105/56.html)
>
> Basiclly.. a few banks (and other people ) are completely blocking _all_
> ICMP messages and "making it so a few people can't see their web pages
> properly". Its been a problem for ages for example with the ASB (you can't
> see all their pages properly if you are going thru a GRE tunnel which
> fragments packets)
>
> User Caused problem nope.. Bank Caused problem yes (as their IT people
seem
> not to know about how to setup their FW's properly)
>
> (all my own opinion)
>
> Thanks
> Craig

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