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Trouble routing between isp's ADSL/SDSL

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MarkHollings

IS-IT--Management
Jul 17, 2003
33
GB
Our existing ADSL internet connection is with an ISP called System Online, originally in partnership with BT I think, at our Head Office.

We have quite happily connected VPN routers at two remote sites using System Online as an ISP too. Additionally we have two other remote sites on BT Openworld connected via VPN to our Head Office too.

As our orgainisation grows we have supplemented the ADSL connection win a new SDSL connection with an different isp again, Spitfire.

We migrated the two remote sites on BT Openworld over to the new SDSL connection to relieve the traffic burden on the ADSL connection.

This where the problems start - until the end of last week the two remote sites on BT OpenWorld were able vpn over the SDSL connection. Now they won't. There seems to be no route between the BT Openworld and the Spitfire networks. We are unable to ping between the router on the SDSL and the routers on the BT Openworld connection.

Furthermore from my Virgin Media connection at home I have, again ,until recently been able to connect to all of the remote sites using there internet ip address. But the connectivity to the remote BT Openworld and System Online hosted sites has now gone too as well as the System Online ADSL connection at Head Office. However I can still VPN over the SDSL connection.

I have tried pinging the respective routers from each of the remote sites. All the BT and System Online (SOL) routers can happily ping one another but are unable to ping the router on the SDSL connection or my home Virgin Media connection, and as mentioned earlier there is no responses when pinging from the VM or Spitfire connections to the BT/SOL connections.

All of the routers have been configured to accept ping etc so there cannot be any firewall issues and if I go offsite and try a remote ping/tracert from the Colt network site all of the remote points respond irrespective of isp.

It would seem that there is a problem in the routing between the isp's, possibly at the BT end as thats where the packets seem to get lost when tracing the route.

As a longshot I tried putting a static route in the routers routing table to route the data via a common point that is accessible from either ISP but with no sucess. Tried, foolishly, reconfiguring the DNS servers to OpenDNS on a router at one of the BT remote sites, which of course took it offline, Dohhhh! The DNS needs to be set specifically for the router to connect to the ISP.

Does anyone have any suggestions as to which way to turn. Is it possible to use offsite DNS to overcome the routing problem and still allow the routers to logon to the ISP?

BT don't seem to have a place to log problems with internet routing issues, and since this isn't a straighforward internet connection problem I fear the helpdesk just won't understand what the problem is here, after all the internet connection is up and most sites are reachable, it's just the one site we need to reach isn't contactable! I have logged the problem with Spitfire and will do the same with SOL tomorrow, but who the hell should you try to talk to at BT?

Whats very frustrating is that this time last week all the remote routers were able to ping one another and able to VPN over either the ADSL or SDSL connections, now they can't and the route over the internet between those on one ISP and those on another isp has gone. Who do I talk to to get it put back? Or is there a way this can be overcome?

Any ideas would be gratefully received, it has taken hours this week and a lot of tearing my hair out to understand what the hell has been happening.

Regards

Mark
 
OK---so what is BT Openworld? A different ISP? I thought you say that spitfire takes care of it now---is the sdsl now spitfire, and USED to be BT Openworld? I am guessing this is wrong, since you're looking for a route between the two...please clarify this. Draw me a picture...

Burt
 
Mark,

Your best bet would to call your ISP. They may be drones, but they have supervisors, and other technicians you can talk to. This looks to me to be a routing issue on the ISP's side, and there's not likely a way you can fix it until your ISP knows what's going on.

One other thought. Are you trying to connect to a domain name, or to an IP address? If you've switched ISP's and you use fully qualified domains to access your remote sites, you'll need to update any necessary domain records to reflect the IP address changes.
hope this helps
-ap
 
Hi
Burt

At our head office we have two internet connections. One, and ADSL max which carries all of the orgainisational browsing traffic and 6 VPN connections. The remote sites use either BT or System online as ISP.

The other connection at our Head Office is the 2MB SDSL connection provided by Spitfire. We have 20 remote VPNs running on this circuit all of whom connect using NTL business broadband.

Ideally I would like to move the VPN connections on the ADSL connection over to the SDSL circuit. THe problem is that there is no internet route between the remote sites on the ADSL circuit and the SDSL endpoint in the office here. Pinging produces no response as the packets get lost.

Adam, I have reported it to the ISP's but they just ask me to trace route from both ends to establish where the route gets lost and then suggest that I should contact the owner of that router and ask them to resolve the problem !!!?!!!.

I am using IP's not names, but I am rapidly coming to the conclusion that the easiest way out of this is to dump both the ISPs and use just one single ISP for all of the services.

Regards

Mark
 
Mark,

The dump and change might be the best way to do it. I used to work for an ISP and it was our policy to help the customer as much as possible, even if the routing issue wasn't in our network. You could always pose as your ISP. The up stream providers have no real way of verifying your identity...
I find it incredulous that your ISP doesn't want to help you. I guess they don't like money... Best of luck to you!

-Adam
 
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