Simple and Often Over Looked RIP

From: Godswill Oletu (oletu@inbox.lv)
Date: Sun May 21 2006 - 11:23:44 ART

Hi,

Hope I am not getting too paranoid.

I find RIP, to be simple but very very deadly. It is not rich in features and flavors like the other IGPs and can be sometime Stubborn to troubleshoot or resolve problems in RIP than in EIGRP, OSPF or BGP.

Most of the commercial labs, that I am been using, employ the class B address space all over the pod, let take a simple topology like this, that is using the 172.16.0.0/16 address space?

R1(172.16.10.1)----------------------------(172.16.10.2)-R5-(172.16.20.2)----------------------(172.16.20.1)R2
                                                                        |
                                                              (172.16.30.2)
                                                                       |
                                                                       |
                                                                       |
                                                               (172.16.30.4)
                                                                       |
                                                                     R4

I do not know if the line diagram above will make it accross in good shape. However, R5 have 3 Fasthethernet interfaces (Fa0/0; Fa0/1 & Fa0/2) )with IP addresses 172.16.10.2; 172.16.20.2 and 172.16.30.2; all /24.

Task:
Enable RIPv2 on R5 and advertise Fastethernet0/0 into the RIP domain.

Question:
Since RIP will default to the classfull network when adding interfaces into the RIP domain, even with RIPv2 and 'no auto-summary' enabled, should one filter out Fa0/1 and Fa0/2 addresses from the advertisement into RIP domain?

I am in the habit of filtering them and advertising just what the task say should be advertised into RIP, but some of the commercial labs I have seen, do not filter out the other advertisements. Wouldn't the proctor be cranky to hop on R4 and see not only Fa0/0 address advertised by RIP but also Fa0/1 address, which he/her did not ask for?

If the keyword 'ONLY' is somewhere in the task, it will lead one to filter the advertisement and be more restrictive; but with the absence of that keyword, what is the best practice?

Is it?

!
router rip
version 2
no auto-summary
network 172.16.0.0
!

And move on OR

router rip
version 2
no auto-summary
network 172.16.0.0
distribute-list 1 out
!
access-list 1 deny 172.16.20.0 0.0.0.255
access-list 1 deny 172.16.30.0 0.0.0.255
access-list 1 permit any
!

This archive was generated by hypermail 2.1.4 : Thu Jun 01 2006 - 06:33:22 ART