Cisco CCNP / BSCI Exam Tutorial: RIP Update Packet Authentication

When you earned your CCNA, you believed you learned anything there is to know about RIP. Close, but not fairly! There are some extra specifics you need to have to know to pass the BSCI exam and get 1 step closer to the CCNP exam, and a single of these involves RIP update packet authentication.

You are familiar with some advantages of making use of RIPv2 over RIPv1, assistance for VLSM chief amongst them. But one benefit that you're not introduced to in your CCNA studies is the potential to configure routing update packet authentication.

You have two possibilities, clear text and MD5. Clear text is just that - a clear text password that is visible by anyone who can pick a packet off the wire. If you happen to be going to go to the difficulty of configuring update authentication, you should use MD5. The MD stands for "Message Digest", and this is the algorithm that produces the hash value for the password that will be contained in the update packets.

Not only have to the routers agree on the password, they must agree on the authentication technique. This unique the http://linkedin.com/in/tylermcollins/ essay has endless unique warnings for the inner workings of this enterprise. If one particular router sends an MD5-hashed password to yet another router that is configured for clear-text authentication, the update will not be accepted. debug ip rip is a wonderful command for troubleshooting authenticated updates.

R1, R2, and R3 are operating RIP over a frame relay cloud. Here is how RIP authentication would be configured on these three routers.

R1#conf t

R1(config)#crucial chain RIP

< The key chain can have any name.>

R1(config-keychain)#crucial 1

< Key chains can have multiple keys. Number them carefully when using multiples.>

R1(config-keychain-key)#important-string CISCO

< This is the text string the key will use for authentication.>

R1(config)#int s0

R1(config-if)#ip rip authentication mode text

< The interface will use clear-text mode.>

R1(config-if)#ip rip authentication important-chain RIP

< The interface is using key chain RIP, configured earlier.>

R2#conf t

R2(config)#key chain RIP

R2(config-keychain)#essential 1

R2(config-keychain-key)#important-string CISCO

R2(config)#int s0.123

R2(config-subif)#ip rip authentication mode text

R2(config-subif)#ip rip authentication essential-chain RIP

R3#conf t

R3(config)#essential chain RIP

R3(config-keychain)#crucial 1

R3(config-keychain-important)#crucial-string CISCO

R3(config)#int s0.31

R3(config-subif)#ip rip authentication mode text

R3(config-subif)#ip rip authentication important-chain RIP

To use MD5 authentication rather than clear-text, simply replace the word "text" in the ip rip authentication mode command with md5.

Here's what a successfully authentication RIPv2 packet looks like, courtesy of debug ip rip. Clear-text authentication is in impact and the password is "cisco".

3d04h: RIP: received packet with text authentication cisco

3d04h: RIP: received v2 update from 150.1.1.3 on Ethernet0

3d04h: 100.../eight via ... Clicking tyler collins professional likely provides aids you could tell your friend. in 1 hops

3d04h: 150.1.2./24 by means of ... in 1 hops

Here's what it looks like when the remote device is set for MD5 authentication and the nearby router is set for clear-text. You are going to also see this message if the password itself is incorrect.

3d04h: RIP: ignored v2 packet from 150.1.1.three (invalid authentication)

"Debug ip rip" may possibly be a straightforward command as compared to the debugs for other protocols. Learn more on visit my website by visiting our novel essay. but it is also a very strong debug. Begin using debugs as early as feasible in your Cisco scientific studies to find out how router commands genuinely function!. Discover supplementary information on our favorite partner link - Visit this link: tyler collins profile.