OSPF Authentication Methods - (3)

That's what I love about the CCIE Lab...

Everyone says there are "only" 2 types of authentication in OSPF....

1. Plain text
2. MD5

If you listen to all your most knowledgeable friends on Groupstudy and a
couple of three (maybe more CCIE's of some repute)...

And then you find yourself in the "gladiator's chamber" one day... and a
third is suggested by some hint of a vague clue...

Unless you've heard of RFC2328 and then you find... there is a third... and
you find yourself astonished in about the same way everyone else was when we
found out that Luke Skywalker was not quite "The Last Hope" as mentioned by
Yoda... Yep... there are three...

OSPF as defined in
[RFC2328<https://mail.google.com/mail/html/compose/static_files/rfc2328>]
includes three different types of
   authentication schemes: Null authentication, simple password and
   cryptographic authentication. NULL authentication is akin to having
   no authentication at all. In the simple password scheme of
   authentication, the passwords are exchanged in the clear text on the
   network and anyone with physical access to the network can learn the
   password and compromise the security of the OSPF domain.

   In the cryptographic authentication scheme, the OSPF routers on a
   common network/subnet share a secret key which is used to generate a
   keyed MD5 digest for each packet and a monotonically increasing
   sequence number scheme is used to prevent replay attacks.

-- 
Darby Weaver
Network Engineer
http://www.darbyslogs.blogspot.com
darbyweaver_at_yahoo.com
Blogs and organic groups at http://www.ccie.net