From: Bill Carter (bcarter@xxxxxxxxxxxxxx)
Date: Thu Dec 02 1999 - 19:49:34 GMT-3
No, but I understand what you are thinking...
With ospf demand-circuits periodic hellos are suppressed and the
periodic refreshes of LSAs are not flooded. OSPF packets only bring
up the circuit when (1) LSAs are exchanged for the first time and (2)
when a change occurs in the information the LSAs contain.
Obviously you don't want the ISDN coming up every time a router
hicups. The dialer list would prevent topology changes from bringing
the ISDN up. Your dialer list would prevent topology changes from
initiaing ISDN connection.
You use OSPF on-demand circuits because the remote router (for
whatever reason) needs an accurate picture of the network. Blocking
LSAs caused by topology changes would not give an accurate picture of
the network.
From a design standpoint, what you are trying to do is prevent every
little topology change from bring the connection up. You want to
isolate the ISDN/OSPF demand circuit from as many LSA's as possible.
To due this, create a Totally Stubby Area and place the OSPF demand
circuit in this area. The TSA only sees intra-area and default
routes. Thus very few LSA's
But...with what you are preparing for you are thinking to hard! Just
make the ISDN interface call the other router, add the interface to
the OSPF network statement, and slap on the ip ospf demand-circuit.
Don't put it in a TSA unless you are told to.
Relax andd don't think to hard...you'll do fine.
Ben Rife wrote:
Do you have to create a restrictive dialer list in addition to
using "ip ospf demand-circuit" on an ISDN line to keep OSPF from
bringing the line up? Refer to the following: int bri 0 ip ospf
demand-circuit dialer-group 1 dialer-list 1 proto ip list
101 access-list 101 deny ip host any host 224.0.0.5
access-list 101 permit ip any any Thanks, Ben
--
~~~~~~~~~~~~~~~~~~~~~~~~
Bill Carter
Senior Network Analyst
Sentinel Technologies
CCIE No.5022
~~~~~~~~~~~~~~~~~~~~~~~~
This archive was generated by hypermail 2.1.4 : Thu Jun 13 2002 - 08:21:58 GMT-3