I am confused about the way a backup interface can be tested. I have come across a testing mechanism whereby the backup interface is removed as a means of testing whether or not it works.
The configuration is as follows:
router01(config-subif)#no backup int bri2
#sh isdn stat
ISDN BRI2 interface
Layer 1 Status:
Layer 2 Status:
TEI = 64, State = MULTIPLE_FRAME_ESTABLISHED
Layer 3 Status:
1 Active Layer 3 Call(s)
Activated dsl 2 CCBs = 1
#sh isdn active
Out XXXXXXXXXXXX Active(72) router02 118
I realise this may appear obvious to some, but I would appreciate it if it could be explained.
I think if you have configured the route, that will make the ISDN interface to dial, even though the backup interface is removed.