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ospf authentication missmatch problem

ChRiStEw1234
Level 1
Level 1

hi all,im doing an ospf lab,ive got it all up an running  and am now trying to add authentication,the lab says use plain text authentication which i believe is type 0.

But when i set up the authentication-key it takes the command but then i get an authentication failed because of a type mismatch even though i never specified a type (type mismatch recieved 0 we use 1),so i go into all interfaces and add the command specifying type 1,all interfaces,all routers but then i get authentication missmatch type 1 we use 0, am i doing somthing wrong ???

thanks chris

1 Accepted Solution

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Yes, the "1" in your command references the key-id (you can have more that one key per interface). You also have to specify your authentication-type ("ip ospf authentication"). The Authentication Type can be specified for the interface and also for the area in the "router ospf" section.

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View solution in original post

10 Replies 10

These are the authentication types as of RFC 2328 (OSPF Version 2):

                  AuType       Description
                  ___________________________________________
                  0            Null authentication
                  1            Simple password
                  2            Cryptographic authentication
                  All others   Reserved for assignment by the
                               IANA (iana@ISI.EDU)


                      Table 20: OSPF authentication types.

You are using "0" what is "no authentication". Plain authentication would be "1".

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hi karston, thanks for your quick reply,i understand the types now but even though on all interfaces i have used the command ip ospf authentication key 1 password  it still says authentication mismatch recieved type 1 we use 0,have i missed a command somewhere???

thanks chris

Yes, the "1" in your command references the key-id (you can have more that one key per interface). You also have to specify your authentication-type ("ip ospf authentication"). The Authentication Type can be specified for the interface and also for the area in the "router ospf" section.

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hi karsten, thanks for that it now works i added the message digest  at the end of ip ospf authentication

thanks

Then it could be that it works, but not the way you think it works ...

If you change to message-digest authentication, you also have to change the command "ip ospf authentication-key ..." to "ip ospf message-digest-key ...". If you miss that your ospf will have a compatible configuration on both ends but won't authenticate.

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hi thanks again will have another mess

chris

hi karsten thanks removed the message digest bit and now works,

thanks chris

can i just ask,with the message digest added i was still able to see the routes added to the routing table and all had adjacency is this right??

Yes, if you have the same config on both sides (authentication set to message-digest but no message-digest-key) then the digest added on one side with "no key" is compatible to the expected authentication wirh "no key" on the other side.

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thanks much appreciated

chris

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