ISDN DDR Routing

[abovebrd]

How do I stop an IP broadcast from bringing up an ISDN DDR link ?

I am attempting to add ISDN DDR links to a frame-relay network for redundancy. However one of the IDSN links wants to dial due to what Ip believe to be IP broadcast traffic.
But thats just a guess at this point.

How do I prevent this from happening ?


sanjose#sh dialer interface bri1/1

BRI1/1 - dialer type = ISDN

Dial String Successes Failures Last DNIS Last status
14441234567 37 45 00:07:02 successful
0 incoming call(s) have been screened.
0 incoming call(s) rejected for callback.

BRI1/1:1 - dialer type = ISDN
Idle timer (300 secs), Fast idle timer (20 secs)
Wait for carrier (30 secs), Re-enable (15 secs)
Dialer state is multilink member
Dial reason: ip (s=10.0.50.1, d=10.0.50.255)
Connected to 14441234567(texas2)

BRI1/1:2 - dialer type = ISDN
Idle timer (300 secs), Fast idle timer (20 secs)
Wait for carrier (30 secs), Re-enable (15 secs)
Dialer state is idle
-Danny
dan@snoboarder.net

 

[wybnormal]

The easiest way is to use an access-list to block everything except what you really need to go across the ISDN link.

!
dialer-list 1 protocol ip list 100
!

this snippet of code will use an access list numbered 100 to filter the traffic.
!
access-list 100 deny icmp any any access-list 100 permit ip any any
!

This list filters out ICMP traffic and allows all other ip traffic. This is easily changed to block whatever you need.

See this link:
Configuring ISDN Backup for Frame Relay

http://www.cisco.com/warp/public/125/fr_isdn_backup.html

MikeS
Find me at

http://www.packetattack.com

"Take advantage of the enemy's unreadiness, make your way by unexpected routes, and attack unguarded spots."
Sun Tzu

 

[OCiTiLLO]

Hi Abovebrd,

:ial reason: ip (s=10.0.50.1, d=10.0.50.255)::


your right, it is broadcast traffic originating from host 10.0.50.1 being sent to broadcast address 10.0.50.255

you may want to 'sniff' the subnet to see what kind of traffic is triggering the call and use an acl like wybnormal suggested.

 

[abovebrd]

Thanks Guys,

-Danny
dan@snoboarder.net