On Sat, Mar 01, 2008 at 11:14:19AM +0000, Wayne Stallwood wrote:
On Fri, 2008-02-29 at 10:53 +0000, Chris G wrote:
Also why why why when BT are shipping their routers to their
customers
they insist on leaving them set at a non optimal MTU for the BT adsl network (which causes issues with several vpn solutions and various other things) is beyond me.
So should I change it? If so, what to?
1458 would be the recommended value for your connection. What you should also do is make sure that from your end at least there is no reason for pMTU not to work (generally your end that would mean making sure ICMP can get out of your network and potentially allowing it in as well) this I think is probably the default behaviour for your router
Generally speaking Path MTU should mean that a MTU setting that is too high on the PC's or your router is irrelevant, however there are a number of systems on the internet that are broken in respect to pMTU which is why occasionally you may get a problem with the default setting of 1500.
OK, thanks for the helpful information.
I have to say that in all my time using the internet (dating back to early Demon "tenner a month" days) I've never (knowingly) suffered from any problems caused by MTU size.