Cisco OSPF and Windows 2000 OSPF won't form adjacency..

[spejic]

Hello,

I've tried everything, but my PC's NIC and Cisco 1600's Ethernet 0, both in Area 0, won't form adjacency.

Cisco 1600 sees PC as a neighbor, while PC doesn't detect Cisco 1600 at all. (not in the neighbor table, nor does it receive any packets from Cisco).

Both elect themselves as DR, with no BDR.

I've tried debug ip ospf adj and debug ip packet,

looks like PC is sending hellos while Cisco is not ????

When I ping Cisco's 224.0.0.5 and 224.0.0.6 the ethernet 0 will not reply. If I configure a loopback interface, it will reply. So will PC.

The timers are the same. So is the area id and subnet mask.

Has anyone experienced the same before ? Any ideas re: further troubleshooting steps ?

(I am just learning about OSPF, so excuse my possible ignorance)

Best regards,

SP

[chuck.price]

To form an adjacency neighbors have to have the following parameters match in the hello packets:

network mask, hello interval, router dead timer and the e-bit.

Also they have to "see" their own address listed in a hello packet received from their neighbor, they exchange LSAs and the databases are synched.

What does your OSPF configuration look like?

[mark-obrien]

Another parameter that must match - Area ID.

Mark

[spejic]

Configuration for Cisco:

router ospf 10

network 192.168.1.0 0.0.0.255 area 0

interface e0

ip address 192.168.1.100 (router ID the same)

Timers left at default

Configuration for W2K:

network 192.168.1.0 area 0

ip address 192.168.1.50 (router ID the same).

Timers left at default (seem to match Cisco's ?)

Again, Cisco sees W2K as neighbor (but does not include it in dr/bdr election), while W2K does not see Cisco as a neighbor.

[chuck.price · Accepted solution]

According to Microsoft, their implementation of OSPF has authentication enabled by default, Cisco doesn't. You might be having an authentication problem between Cisco and Microsoft. Check out this MS link for some more troubleshooting ideas.

http://support.microsoft.com/default.aspx?scid=kb;en-us;159659

[spejic]

Mr. chuck.price@tcada.state.tx.us,

thank you so very much !

(I was looking for documents from MS for troubleshooting OSPF, couldn't find anything; this link of yours refers to NT4.0 server, and I was searching for W2K).

Well, this instantly resolved my issue; I have configured authentication on Cisco -

they are forming adjacency just fine now !!!

Thanks !

[chuck.price]

Glad I could help. If you want to learn more on OSPF, I would highly recommend "Routing TCP/IP Vol I" and the "Cisco OSPF Command and Configuration Handbook" both from Cisco Press.