Subject: A VRRP Scenario

From: Amnon Even-zohar <[email-masked]>
Date: Sun, 19 Nov 2000 16:45:22 +0200

Hi !
Suppose a virtual router is configured with more then one backUp.Since none of the VRRP routers is the IP Address owner ,none of them has a priority of 255 but any other value.Lets say  they own a consecutive priority.(like 100,101,102).
Now the master is down.The router with priority 100 is declared as the master.After a while the original master is up again.

My question :  With what priority will the original master send its advertisment ?.Why ?
	          Does it remember it used to be the original master ?.If so. how ?	

10x for your time,
Regards,

Amnon Even Zohar
Atidim Technological Park, Bldg.4
Tel-Aviv 61131, Israel
Tel:    972-3-645-8595
Fax:  972-3-648-7368
E-mail: [email-masked]

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From: Bob Hinden <[email-masked]>
Date: Sun, 19 Nov 2000 09:26:01 -0800

Amnon,

In your example if the "original master" had a higher priority than 100, it 
would be come master again.  It does not remember it used to be the 
original master.

Bob

At 04:45 PM 11/19/2000 +0200, Amnon Even-zohar wrote:
>Hi !
>Suppose a virtual router is configured with more then one backUp.Since 
>none of the VRRP routers is the IP Address owner ,none of them has a 
>priority of 255 but any other value.Lets say  they own a consecutive 
>priority.(like 100,101,102).
>Now the master is down.The router with priority 100 is declared as the 
>master.After a while the original master is up again.
>

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From: "Aruneesh Salhotra" <[email-masked]>
Date: Mon, 20 Nov 2000 10:03:09 +0530

Hi Amnon
The scenario you have described in your query is a basic example of VRRP in
action.
When the master is up, it keeps sending VRRP advertisments declaring its
priority. Every VRRP router, listens to the advertisments, and whenever one
detects that it hasnt received a VRRP advertisments in a configurabe time
period, it starts sending adevertisments. No VRRP router remembers the
status of the router at any point of time. The only FSM it maintains is the
last VRRP operation, slave or master.
Now when the router with priority 102 becomes the master router, it is in
control of VRRP IP. When the original VRRP Master router (priority 255)
comes up again, it sends a VRRP advertisment, and takes on the VRRP master
router.
If you have any more questions in this respect, please do let me know.
Aruneesh
Nortel Networks