CCIE Pursuit Blog

March 27, 2008

Question Of The Day: 27 March, 2008

Topic: Route Redistribution

The network admin on r1 is tasked with redistributing the EIGRP routes into RIP so that they appear in the routing table of the directly connected router r3 (running RIP only).  Here are the EIGRP routes currently in r1’s routing table:

r1#sh ip route eigrp
     2.0.0.0/32 is subnetted, 1 subnets
D       2.2.2.2 [90/2297856] via 10.1.12.2, 00:07:44, Serial1/0.12
     22.0.0.0/32 is subnetted, 1 subnets
D EX    22.2.2.2 [170/2560512256] via 10.1.12.2, 00:07:44, Serial1/0.12

Here is the configuration on r1:

router rip
 version 2
 redistribute eigrp 100 metric 2 route-map EIGRP->RIP
 passive-interface default
 no passive-interface Serial1/0.13
 network 10.0.0.0
 network 13.0.0.0
 default-metric 4
 no auto-summary
!
route-map EIGRP->RIP permit 10
 set metric 6

On r3, what will be the metric of the redistributed EIGRP routes?  What will be the metric of the locally generated RIP routes (i.e. 13.13.13.13/32)?

I’ll post the answer tomorrow.


Yesterday’s Question

 Question Of The Day: 26 March, 2008 

Topic: Route Redistribution 

r1 is running EIGRP and RIP:

r1#sh ip proto sum
Index Process Name
0     connected
1     static
2     eigrp 100
3     rip

r1 has the following EIGRP routes:

r1#sh ip route eigrp
     2.0.0.0/32 is subnetted, 1 subnets
D       2.2.2.2 [90/2297856] via 10.1.12.2, 00:01:06, Serial1/0.12
     22.0.0.0/32 is subnetted, 1 subnets
D EX    22.2.2.2 [170/2560512256] via 10.1.12.2, 00:00:23, Serial1/0.12

r1’s network admin wants to redistribute the EIGRP routes and pass them on to r3 in the RIP domain (directly connected to r1).  Here is his configuration:

r1(config)#route-map EIGRP->RIP perm 10
r1(config-route-map)#match route-type external
r1(config-route-map)#set tag 1170
r1(config-route-map)#route-map EIGRP->RIP perm 20
r1(config-route-map)#set tag 190
r1(config-route-map)#router rip
r1(config-router)#redistribute eigrp 100 route-map EIGRP->RIP

Which EIGRP routes will appear in r3’s (RIP) routing table?

Answer: NONE

RIP routes on r3 do not include the routes redistributed from EIGRP on r1: 

r3#sh ip route rip
     10.0.0.0/24 is subnetted, 2 subnets
R       10.1.12.0 [120/1] via 10.1.13.1, 00:00:22, Serial1/0
     13.0.0.0/32 is subnetted, 1 subnets
R       13.13.13.13 [120/1] via 10.1.13.1, 00:00:22, Serial1/0

When redistributing routes into RIP you must specify a default metric:

r1(config)#router rip
r1(config-router)#redistribute eigrp 100 metric 3route-map EIGRP->RIP

Now we should see the EIGRP routes in r3’s routing table with a metric of 3:

r3#sh ip route rip
     2.0.0.0/32 is subnetted, 1 subnets
R       2.2.2.2 [120/3] via 10.1.13.1, 00:00:19, Serial1/0
     22.0.0.0/32 is subnetted, 1 subnets
R       22.2.2.2 [120/3] via 10.1.13.1, 00:00:19, Serial1/0
     10.0.0.0/24 is subnetted, 2 subnets
R       10.1.12.0 [120/1] via 10.1.13.1, 00:00:19, Serial1/0
     12.0.0.0/32 is subnetted, 1 subnets
R       12.12.12.12 [120/3] via 10.1.13.1, 00:00:19, Serial1/0
     13.0.0.0/32 is subnetted, 1 subnets
R       13.13.13.13 [120/1] via 10.1.13.1, 00:00:19, Serial1/0

It’s pretty easy to forget the metric as the IOS will not throw an error.  You are basically redistributing the EIGRP routes with a metric of zero.  🙂

Advertisements

3 Comments »

  1. […] Click here for the answer. […]

    Pingback by Question Of The Day: 26 March, 2008 « CCIE Pursuit — March 27, 2008 @ 6:06 am | Reply

  2. Heh. I just completed Narbik Kocharians Advanced Lab Workbooks last week, so it’s been several weeks since I did a combined technologies lab. Last night I was working on IEWB Vol.3 #1, a simple lab. But darned if I couldn’t figure out why my redistribution into RIP wasn’t working. My brain finally popped the question to itself, “Hey, stupid! Did you set a metric?” Duuuhhhh. All was well immediately thereafter.

    One of the things I’ve learned in all these hours of lab practice is that most of my mistakes are with something painfully simple. An interface is not up. A missing FR map statement. Wrong DLCI assignment. ACL or route-map name misspelled. Interface set to passive that should not be, or vice-versa. Bad mask on a network statement. Etc. While I used to spend a lot of time on problems like that, thinking I didn’t understand the technology and the issue must be complicated, now I immediately check for the obvious.

    Comment by Ethan Banks — March 28, 2008 @ 5:05 am | Reply

  3. […]  Question Of The Day: 27 March, 2008  […]

    Pingback by Question Of The Day: 28 March, 2008 « CCIE Pursuit — March 28, 2008 @ 7:05 am | Reply


RSS feed for comments on this post. TrackBack URI

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Blog at WordPress.com.

%d bloggers like this: