When multiple protocols run on the box it is good to have the same
router-id.
User configurable command for router-id is another option. If the user wants
he can
set it the same as loopback address manually for stability reasons.
Whatever method is used to derive the router-id (highest configured ip
address OR
derive some magic 4 byte number ;-)) collision resolution by way of
over-riding command
can be very helpful.

Thanks,
Satish

-----Original Message-----
From: Kumaresan Pramod-APK100 [mailto:pramodMOTOROLA.COM]
Sent: Wednesday, January 16, 2002 5:13 PM
To: OSPFDISCUSS.MICROSOFT.COM
Subject: Re: router id

On our routers, by default, we derive the OSPF Router ID from the Ethernet
MAC Address. It has worked very well for us and saves us from the trouble of
configuring a loopback address ( and some IP Addressing scheme to make sure
we configure unique addresses ).

All we need for the Router ID is some unique number and there needn't be any
rule to specify how you should derive it. It doesn't need to be a reachable
IP address.

Pramod

-----Original Message-----
From: Moy, John [mailto:John.MoySYCAMORENET.COM]
Sent: Wednesday, January 16, 2002 8:11 AM
To: OSPFDISCUSS.MICROSOFT.COM
Subject: Re: router id

Manav-

A loopback address is a good, and common, choice for OSPF
Router ID. You certainly don't want to change OSPF Router IDs
just because an interface goes down -- RFC 2328 recommends using
an interface address, but does not insist that the interface be
operational.

John

> -----Original Message-----
> From: Manav Bhatia [mailto:mnvbhatiaYAHOO.COM]
> Sent: Wednesday, January 16, 2002 10:55 AM
> To: OSPFDISCUSS.MICROSOFT.COM
> Subject: router id
>
>
> Hi,
> A router ID can be either statically configured or is selected by the
> router itself. RFC 2328 recommends that the router select the highest
> address among the list of addresses assigned to its interface
> provided its
> operational. Once an interface address is selected and if the
> interface
> address changes or the interface goes down, a new router ID
> is selected
> from the list of operational interfaces. When the router ID
> changes, the
> OSPF daemon is expected to restart by flushing its self
> originated LSAs and
> originating new LSAs with this new router ID.
>
> Can we then assign loopback addresses to prevent volatility
> or additional
> processing required when an interface who address is selected
> as the router
> ID goes up and down. This concept is present in BGP wherein the BGP
> speakers are peered up on the loopback addresses. Is it
> possible in OSPF?
>
> Regards,
> Manav Bhatia
> ----
> "When you are courting a nice girl an hour seems like a
> second. When you
> sit on a red-hot cinder a second seems like an hour. That's
> relativity."
>
> -Albert Einstein, on relativity
>
>
>
> _________________________________________________________
> Do You Yahoo!?
> Get your free yahoo.com address at http://mail.yahoo.com
>

• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]