From: Voytek Mielczarek (Voytek.Mielczarek@xxxxxxxxxx)
Date: Mon Aug 13 2001 - 02:07:28 GMT-3
What you're talking here about is the networking situation where the command is
eligible or not (both your answers), what I explained here was the command's m
echanics. You just gotta test it to argue the point :)
-----Original Message-----
From: Jay Hennigan [mailto:jay@west.net]
Sent: Monday, 13 August 2001 3:00 PM
To: Voytek Mielczarek
Cc: ccielab@groupstudy.com
Subject: RE: Ospf NBMA strange experience
On Mon, 13 Aug 2001, Voytek Mielczarek wrote:
> NearCCIEs,
Sorry, I no longer qualify. ;-) *
> 1) The "neighbor x.x.x.x priority y" command appears on your router only
> if the "ip ospf priority" value on your local interface is not equal zero.
> Otherwise does not even appear on router mode configuration.
I don't think this is the case. I think you'll find that it appears
if the network type is set to non-broadcast.
The "neighbor x.x.x.x priority y" command sets the priority of a neighbor
on a nonbroadcast type network. It does not affect the priority of the
local router interface. If you configure the frame network as non-broadcast
then hellos will only be sent to those routers with a "neighbor priority"
greater than zero. These will be unicast because you've configured the
network as non-broadcast.
> 2) The "neighbor x.x.x.x priority y" resets to one, because it reads the
> "ip ospf priority" value from the neighbor's interface. If you change the
> priority value on the interface at the other end, your local router will
> read the value if of course you entered the "neighbor x.x.x.x priority y"
> command.
It's only used on non-broadcast networks, and falls into the "ugly hack"
category. It's primarily an X.25 thing but can also be used on frame
relay scenarios. It requires more manual configuration than configuring
point-to-multipoint and letting multicast hellos sort out the DR/BDR
based on the configured priorities of each router. Can also be used
if you've got non-Cisco routers in your network that don't do broadcast
on frame-relay. Keep in mind that frame-relay is by default a non-
broadcast multiple access topology, and it's the keyword "broadcast"
that allows you to overcome this.
Gory details:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/np1_r/1r
prt1/1rospf.htm#xtocid677225
* But I gained a lot from this group and feel obligated to give something back.
-- Jay Hennigan - CCIE #7880 - Network Administration - jay@west.net NetLojix Communications, Inc. - http://www.netlojix.com/ WestNet: Connecting you to the planet. 805 884-6323 **Please read:http://www.groupstudy.com/list/posting.html
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