Subject: Highly Available OSPF Router.

From: [email-masked]
Date: Mon, 16 Feb 2004 01:03:13 -0600

Has anyone implemented an OSPF HA where two or more OSPF routers
appear as one OSPF router to the OSPF neighbors. One of the routers 
(the Master) talks to the external world (OSPF neighbors) and the 
others (the Backups) keep all the dynamic OSPF state (neighbors,
database etc) in sync with the Master. When the Master dies, one of
the backup router takes over immediately without the neighbors
realizing any change in the network ?

If anyone has implemented any such thing, I would like to hear about
how they do it. I would also like to know if the WG would be interested
in standardizing such a mechanism ? At least I think that it will be
a useful thing !!

Regards
Mukesh

---

From: Farshad Tavallaei <[email-masked]>
Date: Sun, 15 Feb 2004 23:14:05 -0800

Mukesh,

What are the benefits of this idea over the current implementation of
OSPF?

Sean

-----Original Message-----
From: Mailing List [mailto:[email-masked]] On Behalf Of
[email-masked]
Sent: Sunday, February 15, 2004 11:03 PM
To: [email-masked]
Subject: Highly Available OSPF Router.

Regards
Mukesh

---

From: Dave Katz <[email-masked]>
Date: Sun, 15 Feb 2004 23:19:20 -0800

I suspect a number of folks are working on things like this.

However, the way you describe it says that it in fact is not subject to
standardization, since it does what it does without the neighbors
realizing (nothing outside the "black box.")  Therefore it is only an
implementation trick, not something to be standardized.

--Dave

---

From: Joris Dobbelsteen <[email-masked]>
Date: Mon, 16 Feb 2004 08:33:20 +0100

Mukesh,

I believe such an implementation would not require an WG standard. There are
numberous techniques available for creating high-availability/load-balancing
clusters, both hardware and software. It is up to an implementators of an
OSPF router (and other routing protocols as well) to ensure the state of the
router is shared between the clusters, conforming to the standard of a
single router.
The use of a intra-cluster communication protocol would be useless, as
different implementations use different structures and might have states
defined differently. This would not allow them to share state efficiently,
if at all possible.

Next I believe this idea is of little use with OSPF. A much simpler and
elegant solution is available: two OSPF routers. Let OSPF take care of
selecting the router which is available, rather than HA/LB
hardware/software. This works just as well, because OSPF is designed for
this task.

- Joris

>From: Mailing List [mailto:[email-masked]] On
>Behalf Of [email-masked]
>Sent: Monday, 16 February 2004 8:03
>Has anyone implemented an OSPF HA where two or more OSPF
>routers appear as one OSPF router to the OSPF neighbors. One
>of the routers (the Master) talks to the external world (OSPF
>neighbors) and the others (the Backups) keep all the dynamic
>OSPF state (neighbors, database etc) in sync with the Master.
>When the Master dies, one of the backup router takes over
>immediately without the neighbors realizing any change in the network ?
>
>If anyone has implemented any such thing, I would like to hear
>about how they do it. I would also like to know if the WG
>would be interested in standardizing such a mechanism ? At
>least I think that it will be a useful thing !!
>
>Regards
>Mukesh
>

---

From: Purvi <[email-masked]>
Date: Thu, 19 Feb 2004 20:48:18 -0800

Mukesh,

I had implemented similar OSPF failover mechanism some years back.
If you have any specific question, let me know.

IMHO, even though this task is not that complex,
solution of this nature is not efficient & not needed in most scenarios.
OSPF protocol in network design itself could be used in
creative ways to provide redundancy... and more..

In my view, standardization or informational  rfc
for the requirements as specified in the email are not desirable.
Its one of the solution, design and implementation issues, specific to the
vendor,
which eventually differentiates one vendor from another.

Regards,
-Purvi

----- Original Message -----
From: <[email-masked]>
To: <[email-masked]>
Sent: Sunday, February 15, 2004 11:03 PM
Subject: Highly Available OSPF Router.

Regards
Mukesh