question about using "ip ospf demand circuit"

[teru-lei]

Hi All,

When using "ip ospf deman circuit", must I also not use "broadcast" parameter in the "dialer map " command in bri interface? I hear that the " broadcast" parameter will make the circuit up even if there is no topology change. Anybody has idea? Thank You!

Best Regards

Teru Lei

[bbranch · Accepted solution]

On broadcast media OSPF demand circuits will not successfully suppress the Hello's, it will only work successfully on point-to-point networks and point-to-multipoint non-broadcast networks

You need to use the IP OSPF NETWORK NON-BROADCAST command to change the interface to a non broadcast media on ISDN or configure it as a point-point interface

The following URL has some good tips on the use of OSPF demand circuits and reasons why the link may stay up - incluing the use of broadcast on ISDN configs:

http://www.cisco.com/en/US/customer/tech/tk826/tk365/technologies_tech_note09186a008009481b.shtml

[rwiesmann]

Hi Teru Lei

There is an issue about broadcast and demand circuit but it think it's not the

broadcast in the dialer map.

As i rememeber it's the ospf interface typ which should not be broadcast.

If you type "sh ip ospf interface" it will show you the ospf network type.

1600#sh ip ospf interface

Serial0 is up, line protocol is up

Internet Address 10.0.0.2/30, Area 0

Process ID 1, Router ID 20.20.20.20, Network Type POINT_TO_POINT,

Cost:64

Transmit Delay is 1 sec, State POINT_TO_POINT,

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

Hello due in 00:00:09

Index 1/1, flood queue length 0

Next 0x0(0)/0x0(0)

Last flood scan length is 0, maximum is 0

Last flood scan time is 0 msec, maximum is 0 msec

Neighbor Count is 0, Adjacent neighbor count is 0

Suppress hello for 0 neighbor(s)

You can change the type with "ip ospt network " on the interface level.

Hope that helps you.

Roger