Unicast Update

Now lets take the LAN Network.

The Given requirement is R1 should form neighbor with ONLY R5. So how to do this?? To do this we can go for EIGRP Static neighbor configuration.

On R1 do the static neighbor configuration to R5.

R1#sh run

 ip authentication mode eigrp 100 md5

 ip authentication key-chain eigrp 100 CISCO

router eigrp 100

 network 150.1.0.0

 network 155.1.0.0

 no auto-summary

 neighbor 155.1.156.5 FastEthernet1/0

R5#sh ip eigrp neighbors

IP-EIGRP neighbors for process 100

H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq

                                            (sec)         (ms)       Cnt Num

0   155.1.156.6             Fa0/0             13 00:04:52  120   720  0  31

Single Side we have given the static configuration means R1 will send all the packet to a unicast address (i.e) 155.1.156.5 But R5 can only accept the multicast packet so R5 will ignore it.

NOTE  Static neighbor should be configure in both side.

R5#sh run

router eigrp 100

 network 150.5.0.0

 network 155.1.0.0

 no auto-summary

 neighbor 155.1.156.1 FastEthernet0/0

R5#sh ip eigrp neighbors

IP-EIGRP neighbors for process 100

H   Address                 Interface       Hold Uptime   SRTT   RTO  Q  Seq

                                            (sec)         (ms)       Cnt Num

0   155.1.156.1             Fa0/0             10 00:01:17  126   756  0  156

Neighbor came up but ONLY between R1 & R5.

Now Lets again given requirement is R1 should form neighbor with R5 and R6 but statically. Lets configure this same like above shown.

Very main thing to note is we have the neighborship but between R1 - R5 and R1 - R5. Updates also exchanging. But R5 loopback 0 is not reachable with R6 and vise versa. Why????

R5#ping 150.6.6.6

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 150.6.6.6, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

R6#ping 150.5.5.5

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 150.5.5.5, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

This behavior is because Split horizon. We have to disable the split horizon on R1 interface.

R1#sh run

interface FastEthernet1/0

 ip address 155.1.156.1 255.255.255.0

 no ip split-horizon eigrp 100

 duplex auto

 speed auto

end

R5#ping 150.6.6.6

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 150.6.6.6, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 16/84/164ms