Checked BT test point with modem still getting ip change every 60's
Ellogg
That is...weird. Unless you are somehow configured to drop and reconnect every 60 seconds, you should retain the same IP address throughout the session.
The wrong netmask is not an issue - that netmask applies to the 'network' that comprises your (modem?) and the far end termination kit: since thats all that is on it it doesn't matter if the netmask is almost anything. However that SHOULD be being dished out by the DHCP along with the IP address, so that fact that it's not consistent suggests that somethng s badly screwed by way of the DHCP being recieved from your ISP.
In fact, putting two and two together and making five, everything you report is consistent with the far end kit having been set up by someone technically equivalent to a gibbon. If they have set up microscopically short DHCP lease times - like 60 seconds - for test purposes..
you will indeed be getting changes to the IP address..if further the whole routing tables are being rebuilt every 60 seconds to compensate, and your IP address changes in the middle of a conversation with a remote machine, packets that should have gone to you will wander off elsewhere.
Can you confirm that you have set the modems or routers up with no specific IP address associated with them - i.e. that they are configured to 'automatic' or 'get address from ISP' etc. ?
If so, then the problem is with the ISP, and you should bully the support people gently to get their far end kit configuration reviewed.
This is the sort of thing that happens when a piece of kit falls over at 3 a.m and the onsite guy gets a spare one and sort of sets it up enough to sort of get it mostly working, without doing a proper job.
OR its possible that you are misunderstanding something and setting every router/modem up badly yourself.
There should be a setup page concerned with setting up names addresses and passwords and other stuff..a dump of the infomation there (change name and password in posting) would help.