OSPF authentication

[chinpohpang851]

I'm not quite sure the diffferences of these 2 commands.

# ip ospf authentication  (on interface)

# area 1 authentication   ( on area)

[Reza Sharifi]

The first one turns on authenticatin for one an interface only and the second one for a whole area.

HTH

[chinpohpang851]

but i tried the second area command it saids..  

Message digest authentication enabled

No key configured, using default key id 0

I'll still need to use #ip ospf authentication-key to create the key?

Just another question, Area 0 is regarded as Backbone area?

[Reza Sharifi]

Yes, have a look at this example:

http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/13697-25.html

Correct, area 0 is also called the backbone area.

HTH

[paul driver]

Hello

Yes area 0 is regarded as the Backbone.

Ospf authentication  2 ways 
Global  = plain text or MD5 (router mode )
Interface = plain text or MD5

Router mode - By default enabled on all ospf interfaces but no key string is defined on the interfaces unless you wish to apply one then a key string  needs to be applied at a per interface basis

router ospf 1
area X authentication  ( message-digest- MD5)

int x/x
ip ospf authentication-key xxx ( Plain authentication)
ip ospf message-digest-key 1 md5 xxx (MD5 authentication )

if you wish NOT to run ospf authentication on a interface

int x/x
ip ospf authentication null


Interface Mode - enabled directly under the interface for which authentication is required

int x/x
ip ospf authentication (message-digest)
ip ospf authentication-key xxx ( Plain authentication)
ip ospf message-digest-key 1 md5 xxx (MD5 authentication )

sh ip ospf interface x/x | in authen

res

Paul

[Ganesh Hariharan]

Hello,

As stated by others ,  The area authentication command in the configuration enables authentication for all the interfaces of the router in a particular area. If you want to configure plain text authentication for an interface then use  ip ospf authentication.

And Yes area 0 is backbone are in OSPF domain / network.

Hope it Helps..

-GI

Rate if it Helps