CCIE Pursuit Blog

September 17, 2008

EIGRP Offset-Lists and Show IP Protocols

Filed under: Cisco,Cisco Certification,EIGRP,IOS — cciepursuit @ 8:12 am
Tags: , , , , ,

It’s funny how you may have done a task many times and not noticed an IOS feature.  I applied an offset-list to some EIGRP routes and stumbled across some output I had never noticed before (to be fair I usually use offset-lists with RIP and not EIGRP):

No EIGRP offset-list(s) applied:

Rack17SW1#sh ip proto
*** IP Routing is NSF aware ***

Routing Protocol is “eigrp 10”
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
  Redistributing: eigrp 10
  EIGRP NSF-aware route hold timer is 240s
  Automatic network summarization is not in effect
  Maximum path: 4
  Routing for Networks:
    0.0.0.0
  Routing Information Sources:
    Gateway         Distance      Last Update
    156.17.27.2           90      00:24:46
    156.17.67.6           90      00:24:46
  Distance: internal 90 external 170

With the offset-lists applied (different paths based on whether the 3rd octet is even or odd):

router eigrp 10
 timers active-time 5
 offset-list ODD in 666666666 Vlan18
 offset-list EVEN in 666666666 Vlan58

 network 0.0.0.0
 no auto-summary
!
ip access-list standard EVEN
 permit 0.0.0.0 255.255.254.255
ip access-list standard ODD
 permit 0.0.1.0 255.255.254.255

Notice the difference?  🙂

Rack17SW2#sh ip proto
*** IP Routing is NSF aware ***

Routing Protocol is “eigrp 10”
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Incoming routes in Vlan18 will have 666666666 added to metric if on list ODD
  Incoming routes in Vlan58 will have 666666666 added to metric if on list EVEN

  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  EIGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  EIGRP maximum hopcount 100
  EIGRP maximum metric variance 1
  Redistributing: eigrp 10
  EIGRP NSF-aware route hold timer is 240s
  Automatic network summarization is not in effect
  Maximum path: 4
  Routing for Networks:
    0.0.0.0
  Routing Information Sources:
    Gateway         Distance      Last Update
    156.17.18.1           90      00:17:55
    156.17.58.5           90      00:17:55
  Distance: internal 90 external 170

Advertisements

2 Comments »

  1. This is the first time I comment here and I should say you share genuine, and quality information for other bloggers! Great job.
    p.s. You have a very good template for your blog. Where have you got it from?

    Comment by hydraulic jacks — March 14, 2009 @ 7:36 am | Reply

  2. Sorry i dont see the difference but i have no expirience with the offset feature. (ccnp only no word about it in the bcsi exam)
    please explane it for me! Thx

    Comment by Becomccie — October 2, 2009 @ 4:47 pm | 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

Create a free website or blog at WordPress.com.

%d bloggers like this: