RE: WAAS Central Manager deployment - separate subnets

Dale,

My experience is limited with the WAAS product, but it seems this would be possible with the Autoregistration feature, the WAE's automatically register with the CM.

http://www.cisco.com/en/US/docs/app_ntwk_services/waas/waas/v413/configuration/guide/planning.html#wp1041608

The WAE's can also operate headless in the event that one of the CM's is down. As for the failover process, so you can centrally manage them again :), I don't know how quick that failover would happen or how you would synchronize between your information between them. All the rules / policies are stored on the CM and then pushed down to the WAE's. I would imagine that there must be some master / slave relationship between the CM, but I have found no information on that, other than white papers that say it can be done.

http://www.cisco.com/en/US/prod/collateral/contnetw/ps5680/ps6870/prod_white_paper0900aecd8051c133.html

" Cisco WAAS Central Manager
The Cisco WAAS Central Manager provides secure and scalable central management and monitoring of all Cisco WAEs within a Cisco WAAS topology. The Cisco WAAS Central Manager can be deployed in an active-standby high-availability fashion, where one Cisco WAE acts as the primary Central Manager and another Cisco WAE acts as a standby node. Configuration changes that are made on the primary Central Manager, as well as monitoring data received from Cisco WAEs within the topology, are automatically distributed to the standby Central Manager. If the primary Central Manager fails, the standby Central Manager is promoted to primary and assumes responsibility on behalf of the failed node. If no Central Manager is available, the WAEs within the WAAS topology continue to operate without disruption."

As far as that actual design goes and how it is managed in a failover scenario, I don't entirely know if they are implying some type of DNS based failover or what.

Have you pinged your trusted SE yet?

-ryan

-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Dale Shaw
Sent: Tuesday, June 02, 2009 2:31 AM
To: Cisco certification
Subject: OT: WAAS Central Manager deployment - separate subnets

Hi all,

Sorry for the OT, but the collective brain power available is too hard
to resist!

Has anyone who has deployed WAAS, deployed a primary and standby
Central Manager WAEs across separate subnets?

The document entitled "Enterprise Data Center Wide Area Application
Services (WAAS) Design Guide" states:

"Cisco recommends installing two CMs for WAAS deployment: a primary
and a standby. It is preferable to deploy the two CMs in different
subnets and different geographical locations if possible."

This raises some questions in my mind. I know that the process of
bringing the standby CM up as the primary requires manual
intervention, but assuming the primary dies and the standby comes up,
how do the WAE deployed throughout the network in
"application-accelerator" mode know how to communicate with the
standby (now primary) CM? Its IP address is not the same as the dead
primary.

The only feasible scenario I can think of is that once the standby CM
comes up as the primary, it actively communicates with the deployed
WAEs and informs them of the change in CM IP address. The problem is,
I can't find any Cisco documentation that verifies this. There doesn't
seem to be a way to configure the deployed WAEs with the IP address of
the standby CM -- just a single "central-manager address x.x.x.x"
command, which under normal conditions points at the primary CM IP
address.

The alternative is that, in the event of a primary CM failure, each
WAE needs to be manually reconfigured to point at the standby (now
primary) CM IP address. If that's the case -- yuck!

Can anyone clear this up?

cheers,
Dale

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Received on Tue Jun 02 2009 - 10:00:25 ART