Many thanks chaps......that has haelped a lot...
another question though is :-
if i have 30 async ports on an access server,
assign the same loopback interface to all 30 ports
set all ports to unmumbered
and have only IP address ........can this work????/and if so how does it
tell the different ports????
i`m guessing it just uses the port number ....IF it works
many thanks
steve
>From: "Atif Awan" <[EMAIL PROTECTED]>
>Reply-To: "Atif Awan" <[EMAIL PROTECTED]>
>To: "Stephen Skinner" <[EMAIL PROTECTED]>, <[EMAIL PROTECTED]>
>Subject: RE: BCRAN Loopback int
>Date: Tue, 12 Sep 2000 17:13:27 +0500
>
>
>You define a loopback interface using the global configuration mode
>command:
>
>int loopback 0
>
>It immediately creates a virtual interface which is by default in the up/up
>state. This interface does not depend on other things ( like keepalives,
>clocking, physical cable connectivity ) to remain in the up/up state and
>remains up as long as the router is up and running.
>
>Take OSPF for example. In order for OSPF to function properly it requires a
>Router ID which is the highest IP address of an active interface on the
>router. In case you have loopback interfaces configured then the highest ip
>address amongst those of the loopback interfaces will be chosen as the
>router ID. The advantage you get is that if the Router ID is the ip address
>of a physical interface and the interface goes down then the OSPF operation
>is interrupted. However, if the Router ID is that of a loopback interface
>then the OSPF operation will never get interrupted as long as the router
>itself does not go down and a router going down is very uncommon as
>compared
>to an interface going down.
>
>BGP is another routing protocol that makes use of this advantage of the
>loopback interface.
>
>I hope this clears up things a bit.
>
>Regards
>Atif
>
>-----Original Message-----
>From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of
>Stephen Skinner
>Sent: Tuesday, September 12, 2000 4:35 PM
>To: [EMAIL PROTECTED]
>Subject: BCRAN Loopback int
>
>
>Chuck,Altif,Priscilla.....save me.....
>
>it says in my book BCRAN
>
>"a loopback interface is a virtual interface that never goes down
>,therefore
>it is an ideal line to use as the reference when using the ip unnumbered
>command"
>
>i don`t understand ... a loopback interface dosen`t go
>anywhere????...how,why would i reference this ....Can i have a real world
>example as i don`t seem to understand WHY i would do this....
>
>sorry i`m being a bit thick
>
>thanks to ALL in advance
>_________________________________________________________________________
>Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
>
>Share information about yourself, create your own public profile at
>http://profiles.msn.com.
>
>**NOTE: New CCNA/CCDA List has been formed. For more information go to
>http://www.groupstudy.com/list/Associates.html
>_________________________________
>UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
>FAQ, list archives, and subscription info: http://www.groupstudy.com
>Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
>
>**NOTE: New CCNA/CCDA List has been formed. For more information go to
>http://www.groupstudy.com/list/Associates.html
>_________________________________
>UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
>FAQ, list archives, and subscription info: http://www.groupstudy.com
>Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
Share information about yourself, create your own public profile at
http://profiles.msn.com.
**NOTE: New CCNA/CCDA List has been formed. For more information go to
http://www.groupstudy.com/list/Associates.html
_________________________________
UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html
FAQ, list archives, and subscription info: http://www.groupstudy.com
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
