ISDN Configuration

[ngopinath]

Hello,

I have 1 64kps & 1 2mbps links ro our regional office.

I want to configure ISDN in such a way that if only both 64kps & 2mbps are down then only ISDN should fire.

Any help in this...

Thanx

[thisisshanky]

I would suggest floating statics as a good way to kick the ISDN link. So you will configure default routes (assume) pointing to the 2mbps link (primary) and then the 64 kbps link (secondary) and then the ISDN link (teritiary)

ip route 0.0.0.0 0.0.0.0 serial 0

ip route 0.0.0.0 0.0.0.0 serial 1 20

ip route 0.0.0.0 0.0.0.0 dialer 0 30

When the 2 mbps link go down (serial 0) packets will still route through serial 1 (64 k link) and when that link goes down, it will go through dialer 0 (ISDN) interface. When either one of the links (serial 0 or serial 1) comes up, traffic will re route through either of the active links..(serial 0 or serial 1)...

This can become an administrative nightmare if you have to define multiple static networks (rather than default routes)...

[ngopinath]

hi,

Thanx a lot for ur quick response..

Can u just explain how the configuration should be done..

I have one s0/0 & one s1/0 & onr bri 0/0 ...

When will ISDN fire if i put ip routes with priority as above..

Regds,

[Kevin Dorrell]

Shanky,

There is a trick to avoid the administrative nightmare when using multiple statics. That is, aim the multiple statics all at a loopback interface in the remote router. Then you only need the three floating statics for that loopback.

Kevin Dorrell

Luxembourg