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How would I enable ospf?

How would I enable ospf?
Avatar of Les Moore
Les Moore
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Can you be more specific and provide some details?
Like, enable ospf on what? A Cisco router? A Windows server? A different brand router?
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a cisco router, the corporate has a 1721 router, and i have 8 clients sites that have a 2610 router.  i want to let them talk through ospf, how do I do that?  right now for example my e0 is 192.168.85.1 and s0/0 is 63.146.240.210 which is my corporate router.  and one of my client sites are like e010.1.110.1 and s0/0 is 63.146.240.226.  how do i enable ospf on them?
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Les Moore
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so with my other client sites that are as following:

clientC
s0/0 63.146.240.230

clientD
63.146.240.231

clientE
63.146.240.232

clientF
63.146.240.233


My corporate router will look like:

router ospf 100
network 63.146.240.210 0.0.0.0 area 0
network 63.146.240.230 0.0.0.0 area 0
network 63.146.240.231 0.0.0.0 area 0
network 63.146.240.232 0.0.0.0 area 0
network 63.146.240.233 0.0.0.0 area 0
redistribute connected

My clientC router
router ospf 100
network 63.146.240.230 0.0.0.0 area 0
redistribute connected

My clientD router
network 63.146.240.231 0.0.0.0 area 0
redistribute connected

My clientE router
network 63.146.240.232 0.0.0.0 area 0
redistribute connected

My clientF router
network 63.146.240.233 0.0.0.0 area 0
redistribute connected

Would it look like that?  but I saw with cisco that it's suppose to be like,      63.0.0.0 0.255.255.255 area 0, since this is a class A network.  Do I do it your way which is 63.146.240.226 0.0.0.0 area 0?
And for each s0/0 on each router, do I need to make a command:


ip ospf authentication-key password
Your corporate router only has to have its own serial ip.
You do not need the authentication. Worry about that, if you want to implement it, after you get everything talking.

The network statement only identifies the local links that will participate in the ospf process, and listen for neighbors and updates.
If you have multiple interfaces all in the same subnet, then use the appropriate subnet, not necessarily the classful. Since yours are all single IP's, then there is no value in using the classful "63.0.0.0 0.255.255.255". You may at some point grow and have new interfaces that you need to subnet and perhaps you don't want a particular interface to participate in ospf, or to participate in a different area. My way just gives you ultimate flexibility and control from the very start.
Would I need to make any changes to my routing table?  And do you recommend to use authentication or I don't really need it?

My ISP is with Qwest, which I have to go through them to get to my other sites, do they need to be notify and make any changes to their routers to enable ospf on my serial lines?
If your serial connections are through an ISP, then most likely you will not be able to use your own dynamic routing protocol, ospf or other.

>Would I need to make any changes to my routing table?
Yes. The whole purpose of OSPF is to have dynamic routing tables..

What, exactly, are you trying to accmplish?
Ohhh, so if the serial connections is through an ISP (like Qwest), then I can't have my own dynamic routing protocol, which means I can't use ospf.  Correct?


What kind of changes would I need to make on my routing table?


I need to create a dial backup, just in case if my serial fails, my dial backup kicks in using a usrobotics 56k modem to dial into my corporate router.  As to my understanding, without ospf then my dial backup plan won't work without it because it needs to be smart enough to learn new routes.  Correct?
Serial connections to an ISP will not allow you to run your own dynamic routing, correct. ISP's only use BGP to customer premesis. BGP will not help you in your case.

IF you were running a dynamic protocol, you would not have static routes, so you would remove them.

For a dial backup solution, a simple static route would usually be sufficient, perhaps with a higher cost specified.
Good backgrounder:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1828/products_configuration_guide_chapter09186a0080087225.html

Detailed information on using floating static routes for dial backup. This example uses ISDN, but the principles are the same for analog dial:
http://www.cisco.com/en/US/tech/tk801/tk133/technologies_configuration_example09186a0080093f7e.shtml



If the S0/0 addresses of the remote sites really are as indicated, the ISP is providing a virtual network where all of these branch offices think they're on a single shared subnet.  If this virtual network will pass multicast traffic, then OSPF could work between them.  It might be an interesting experiment.

If that's not the case, though, you would be trying to provide, to the ISP, routing for your various local private networks; even if they are willing to accept OSPF from you (unlikely!), they should filter out such routes.