OSPF & HSRP

[lacox]

Hi all,

I'm wondering if anybody might be able to point me in the right

Direction...

I have 2 7500 router, one pretty much mirrors the other & has HSRP set up

Between them and I'm tracking on the interface that connects to our provider.

Now, I would like to run OSPF internally between the 2 7500's (not load sharing to our provider). What I am trying to figure out is how to have an HSRP event, trigger an OSPF re-convergence and have all of outbound traffic flow out the secondary path.

Do I need to have additional parameters setup to work HSRP with OSPF?

Thanks in advance!

[aretana]

Larry:

In short, you don't need HSRP to tell OSPF when to switch.

The path outbound in OSPF will be represented by a default route (one originated from each router). If the origination of the default in OSPF is tied to the state of the interface, then when the interface in the primary fails, OSPF will flush that default and reconverge to the other router.

Take a look at this: http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_command_reference_chapter09186a00801a807f.html#1038457

Use a route-map to match the address of the interface you're tracking. :-)

Alvaro.

[lacox]

Alvaro,

Thanks that was helpful, but I was wondering if you had more refernce materail, URL's or Cisco Press book that might me helpful. One other question

So your saying that I could get rid of HSRP from the my attached design?? how would that change things.???

[vcjones]

It's not Cisco Press, but you would probably find my book -- High Availability Networking with Cisco -- helpful. A few of the items you would learn:

HSRP is still needed. It protects your users from router failure.

OSPF is also needed. It protects your users from link failure.

The two protocols protect against different failure modes and operate independently. Both are necessary, neither is sufficient, and even with both there are vulnerabilities which leave you with single points of failure.

For example, you may find that BGP is also needed. This depends upon the technology used for your ISP links (OSPF can't protect you from link failures which the router does not know about, and your ISP is not going to run OSPF with you). Plus there are a wide range of other considerations to keep in mind when implementing redundancy to ensure that the extra hardware helps you rather than hurts you!

Good luck and have fun!

Vincent C Jones

www.networkingunlimited.com