ISDN line not dropped

[cjackson]

I have a Cisco 803 connected via ISDN to one of our remote locations. I also have a huge phone bill which seams to show the connection opening at the start of day and closing at the end. All our other lines just open on demand.

I'm a Cisco virgin and have no idea how to start troubleshooting this, can anyone help?

Thanks in advance for any help or advice.

Cheers

Chris

 

[UNIX72]

Are you running any NT servers? Post your running config!

 

[migueljr3]

What protocol are you running on your LAN?
I have the same problem via Apple packets igniting ISDN
calls.
I currently issue a ISDN backup check and run a extended
ping every night(client request). Overkill if I do say so myself.
For some reason the line stays up and I have to manually
shut(then no shut to keep it active) the specific bri.
I am still researching this...Any one have any suggestions?

 

[Poider]

You need to work out what type of traffic you want to force the line to dial, then create a dialer-list pointing to an access-list that allows that traffic and blocks everything else, and then assign that dialer-list to the dialling interface.

 

[cjackson]

Sorry its taken a while for me to reply I have been away for a while.

As I said I'm a Cisco vergin so forgive any stupid errors or comments...

UNIX72

Yes we are running NT servers, where can I find the running config?

migueljr3

We are running TCP/IP

Poider

The remote site needs to connect to our head office location for two reasons:

To access e-mail running on Exchange server

To access a cleint/server database running on AIX 4.3, which needs to be available on demand.

How do I create/ setup the dialer list and access list you are talking about?

Thanks for everyones replies, and thnaks in advance for any more help.

 

[jacro]

Hi cjackson!

If you are using NT-servers, they are very noisy.
To avoid them opening your network you have to put an access-list in your dialer-interface.
here is an example which removes "NT-noise" from opening the line.

access-list 121 deny udp any eq netbios-dgm any
access-list 121 deny udp any eq netbios-ns any
access-list 121 deny udp any eq netbios-ss any
access-list 121 deny tcp any eq 137 any
access-list 121 deny tcp any eq 138 any
access-list 121 deny tcp any eq 139 any
access-list 121 permit ip any any
dialer-list 1 protocol ip list 121

The access-list deny netbios-dgm,-ns ans -ss from opening the line and permit all the other traffic to pass through.

I hope this helps.