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isdn backup for internet leased line


iam having internet leased line of bsnl

i want configure internet isdn line of another isp as backup for leased line

my router model is 1721

is it possible to do it


Re: isdn backup for internet leased line


do clarify about the local lan ip pool whether its on a public space or in private space ?

If its the normal private block and NAT which is normally used for internet access then define a static default route with some metric via the dialer interface or bri interface whichever you use to trigger the isdn line.

Also do a overload over the bri or dialer interface whichever is applicable here similar to what you might have done with your leased line..

if its not the general setup better you throw some lite on the kinda servers you have in ur internal lan and the kinda addressing as well nat been deployed at present.


Re: isdn backup for internet leased line

yeah it is possible, all what you need to do is...

router#conf t

router(config)#interface serial 0

router(config-if)#backup interface bri0

make sure that you have BRI card installed in the router & you have configured the "Bri0" interface for connecting to internet via ISDN.

when the above said configuration is done, the "backup interface Bri0" command will wake up as soon as the serial 0 interface is going down & also when the serial 0 interface is up, Bri0 interface will will in standby.

hope this helps,

rate this post.

Re: isdn backup for internet leased line

hi arun...

you can use any of the following confiugration as per your requirement...

Backup Interface:

Dialer Watch:

all in one:

if you want more help then let us know...

rate this post if it helps



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