Are OSPF routing protocol exchanges authenticated?

Yes, OSPF can authenticate all packets exchanged between neighbors. Authentication may be through simple passwords or through MD5 cryptographic checksums. To configure simple password authentication for an area, use the command ip ospf authentication-key to assign a password of up to eight octets to each interface attached to the area. Then, issue the area x [...]

Is it possible to use distribute-list command to filter routes in OSPF?

Configuring distribute-list commands that utilize route maps will not achieve desired Link State Advertisement (LSA) filtering. Open Shortest Path First Protocol (OSPF) routes cannot be filtered from entering the OSPF database using distribute-list. The distribute-list in command only filters routes from entering the routing table, and it does not prevent LSA packets from being propagated. [...]

How to enable authentication in OSPF?

There are two ways of authentication in OSPF. 1) Clear text authentication 2) MD5 authentication 1) Clear text authentication Area based authentication Cisco_Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Cisco_Router(config)#interface f0/0 Cisco_Router(config-if)#ip ospf authentication-key [email protected] Cisco_Router(config-if)#exit Cisco_Router(config)#router ospf 100 Cisco_Router(config-router)#area 2 authentication Cisco_Router(config-router)#exit Interface based authentication Cisco_Router(config)#int fa0/0 Cisco_Router(config-if)#ip ospf authentication [...]

What are network types available in OSPF?

Broadcast Default on broadcast medias (Ethernet / Token Ring) Sends hellos as multicast Performs DR/BDR Election Non-Broadcast Default on multipoint NBMA medias (Frame Relay / ATM) Sends hellos as unicast (“neighbor” command) Performs DR/BDR Election Point-to-Point Default on point-to-point medias (HDLC / PPP) Sends hellos as multicast No DR/BDR Election Only two neighbors on the [...]

If you have the two routers in the same area, can you use the distribute-list out command to filter resources between them

No to filter the routes use the command distribute-list in command not the distribute-list out. To filter networks received in updates, use the distribute-list in command in address family or router configuration mode. To change or cancel the filter, use the no form of this command. distribute-list [access-list-number | name] | [route-map map-tag] in [interface-type [...]

What are different types of stub areas in OSPF

OSPF relies on several types of Link State Advertisements (LSAs) to communicate link state information between neighbors. A brief review of the most applicable LSA types: Type 1 – Represents a router Type 2 – Represents the pseudonode (designated router) for a multiaccess link Type 3 – A network link summary (internal route) Type 4 – Represents an ASBR Type 5 – [...]

Can you explain different OSPF packet types

Hello-Used to discover and maintain neighbours. Database Description-Used to form adjacencies. The router summarises all its linkstate advertisements and passes this information, via database description packets to the router it is forming an adjacency with Link State Request After the database description packets have been exchanged with a neighbour, the router may detect link state advertisements it requires to update [...]