Is there a problem if I use dialer watch without dialer-group?

Question

I use isdn as back up intface,and use dialer watch to monitor.
my configuration is :
interface BRI0/0
description ***To 11.228.244.1***
ip address 11.228.244.2 255.255.255.128
encapsulation ppp
no ip route-cache
no ip mroute-cache
dialer map ip 11.228.244.1 name C-3640-01 broadcast 02080000759
dialer map ip 11.228.8.62 name C-3640-01 broadcast 02080000759
dialer watch-disable 10
dialer watch-group 1
isdn switch-type basic-net3
no peer neighbor-route
no cdp enable
ppp authentication chap
dialer load-threshold 128 either
ppp multilink
dialer watch-list 1 ip 11.228.8.62 255.255.255.255
dialer watch-list 1 ip 11.228.8.61 255.255.255.255
dialer watch-list 1 delay disconnect 10
As you can see,no "dialer-group" command in my configuration.
When I shut down the primary interface,my isdn dialer up correctly,and learn the route from bri0/0.When my primary interface up again,my isdn interface disconnect as expected.
All seems good,so is the "dialer-group" needed in the configuration of dialer watch ?

Answer 1

Hello,
that is actually the default behaviour of dialer watch, it does not depend solely on interesting traffic to trigger the backup. As soon as the primary link goes down, dialer watch brings up the secondary link.
Check the explanation on CCO regarding dialer watch:
Dialer Watch Overview
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fdial_c/fnsprt6/dcdbakdw.htm#wp1000889
HTH,
GP