Hi,

I am trying to set up belt and braces Internet Access for a client.

They had a Zen ADSL connection which was acessed using a 2600i with ISDN backup (Zen offer ISDN backup with the same IPs as your ADSL connection). The trouble is that the client needed more upstream bandwidth and more reliability (even one or two days a year back down to ISDN is a problem). Their exchange is not SDSL enabled.

Accordingly they now also have a BTNet 10Mbit LES leased line connected to WAN1 of a 3300. The obvious way to go is to set the 2600i to be in PPPoE pass-through mode and then set it as a backup on WAN2. My question is will the ISDN backup work in this senario, or do I need to use No-NAT to get this working?

On a related issue, how should I deal with the fact that inbound services will be targeted at the WAN1 LES IP addresses so that if (when:) the LES fails these IPs will be unavailable and inbound services will need to be redirected to the WAN2 ADSL/ISDN IP addresses. My only idea so far is to create DNS records with very short TTLs, say 5 minutes, and manually change the DNS records if/when the LES falls over. Is there any other way of doing this? Also if I do things like this, how will I know that the LES has failed? Ideally an email could be sent when this happens, the 3300 doesn't seem to have this facility, maybe I can use SNMP or syslog to catch this occurence and send a mail, does anyone have any ideas?

Thanks in advance for any wisdom received.

Chris.

As you're using a leased line separately from the Vigor2600i - i.e. the ADSL interface is not in use, then ISDN "backup" is not appropriate as the ADSL is never up in the first place, or dfo you mean that you still have ADSL and that is your backup?

Sorry, what I mean is that if the leased line goes down and the ADSL goes down I want the ISDN to kick in. So the 3300 is using the 2600i and the 2600i is using the ISDN line. But I'm not sure that's possible when using a 2600i in PPPoE mode.

Is what your saying is that the WAN2 Interface won't be brought up until needed if it is configured as a backup? I assumed it would be held up in readiness.

c.edwards, how's your performance? We find we can only get a 10M Half-Duplex connection from the Vigor3300V, setting to 10M Full-Duplex causes no connection/no traffic to be able to go through.

Having it at half duplex of course ruins the performance, but it is a connection.

Unfortunately we aren't running this setup any more and I can't remember.