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Offset list CCIE Question


In this scenario R1 connect R2 with different bandwidth line. If we can't change EIGRP 'k' values, bandwidth and delay on the existing interfaces and only involve EIGRP, offset list is the way to solve this cause.

 Now R1 know only one route to 3.3.3.0/24 network.
R1#sh ip route eigrp
     3.0.0.0/24 is subnetted, 1 subnets
D       3.3.3.0 [90/3142400] via 10.10.12.2, 00:48:21, Serial0/0
     10.0.0.0/24 is subnetted, 3 subnets
D       10.10.23.0 [90/3014400] via 10.10.12.2, 00:53:18, Serial0/0
We see R1 have only one path to 3.3/14 network.Now I will set offset list on R2. First I need to check R1 metric value for 3.3.3.0/24 network.

 R1#sh ip eigrp top
IP-EIGRP Topology Table for AS(123)/ID(1.1.1.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - reply Status, s - sia Status

P 1.1.1.0/24, 1 successors, FD is 128256
        via Connected, Loopback0
P 3.3.3.0/24, 1 successors, FD is 3142400
        via 10.10.12.2 (3142400/156160), Serial0/0
        via 10.10.21.2 (5642496/156160), Serial0/1
P 10.10.12.0/24, 1 successors, FD is 3011840
        via Connected, Serial0/0
        via 10.10.21.2 (6023936/2169856), Serial0/1
P 10.10.21.0/24, 1 successors, FD is 5511936
        via Connected, Serial0/1
        via 10.10.12.2 (3523840/2169856), Serial0/0
P 10.10.23.0/24, 1 successors, FD is 3014400
        via 10.10.12.2 (3014400/28160), Serial0/0
        via 10.10.21.2 (5514496/28160), Serial0/1


Offset list is influence metric values so I need to setup s0/0 metric value to 5642496 for load balancing.
First step access list need.
R2(config)#access-list 1 permit 3.3.3.0 0.0.0.255

 Second offset list set at EIGRP.

 router eigrp 123
 offset-list 1 out 2500096 Serial0/0


Now we can verify on R1 routing table.

R1#sh ip route eigrp
     3.0.0.0/24 is subnetted, 1 subnets
D       3.3.3.0 [90/5642496] via 10.10.21.2, 00:00:07, Serial0/1
                [90/5642496] via 10.10.12.2, 00:00:07, Serial0/0
     10.0.0.0/24 is subnetted, 3 subnets
D       10.10.23.0 [90/3014400] via 10.10.12.2, 00:00:07, Serial0/0

Some time we need to clear EIGRP process with #clear ip eigrp neighbor

R1#traceroute 3.3.3.3
  1 10.10.21.2 56 msec
    10.10.12.2 64 msec
    10.10.21.2 64 msec
  2 10.10.23.3 96 msec 96 msec 64 msec

 If we set the offset list on R1 config like below.
#offset-list 1 in 2500096 Serial0/0   

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