This configuration is an example of EIGRP Over NBMA configuration. EIGRP Over NBMA is a form of EIGRP configuration.
1) Configure EIGRP with AS 25.
2) Each router should make summarization to decrease the routing table.
3) Make the configuration for that EIGRP uses %30 more bandwith due to default config. ( On the serial interface of the HO router ).
4) Enable authentication on all EIGRP routers using the authentication keys below.
KEY-1=passphrase : cisco1
Accepted from : Midnight on Jan 1 2010 until mid. On Feb 1 2010
Sent from :
KEY-2=passphrase : cisco2
Accepted from : Jan 28 2010 until eternity
Sent from :
EIGRP OVER NBMA CONFIGURATION
R1#show ip route 192.168.10.0/24 is variably subnetted 3 subnets ,2 masks D 192.168.10.0/24 is a summary,Null 0 C 192.168.10.4/30 is directly connected 172.16.0.0/16 is variably subnetted .. D 172.16.0.0/16 is a summary, Null 0 C 172.16.1.0/24 is directly connected B 172.16.2.0/24 via .. C 172.16.3.0/30 is directly connected
“Null 0” routes are created if only there is one subnet learnt by EIGRP and auto-summary is activated.
HO Router: (A)
HO(config)#router eigrp 25 HO(config-router)#network 10.1.0.0 0.0.255.255 HO(config-router)#network 172.16.0.0 HO(config-router)#no auto –summary
If auto-summary is not closed, all the routers ( HO, EAST and WEST announce that 10.0.0.0 to cloud and no neighborship can be established.
East Router: (B)
East(config)#router eigrp 25 East(config)#network 10.2.0.0 0.0.255.255 East(config)#network 172.16.0.0 East(config)#no auto
West Router: (C)
West(config)#router eigrp 25 West(config)#network 10.3.0.0 0.0.255.255 West(config)#network 172.16.0.0 West(config)#no auto
After A – B and C configurations steps lets do a show ip route on EAST router…
East#show ip route D 10.1.3.0 D 10.1.2.0 D 10.1.1.0 C 10.2.3.0 C 10.2.2.0 C 10.2.1.0
As you see, 10.3.3.0 , 10.3.2.0 and 10.3.1.0 is not in the routing table. But you can see these networks in the HO router’s routing table. After the configuration step “D” you can see 0.3.3.0 , 10.3.2.0 and 10.3.1.0 in the East router’s routing table too.
HO Router: (D)
HO(config)#interface s 0/0.1 HO(config-if)#no ip split–horizon eigrp 25 // split horizon was closed for eigrp 25 //
FOR HO:
10.1.1.0 10.1.2.0 // 10.1.0.0/28 // 10.1.3.0
HO & East & West Routers: (E)
HO(config)#interface s0/0.1 HO(config-if)#ip summary-address eigrp 25 10.1.0.0 255.255.252.0 // config for summarization which is wanted at question 2 // East(config)# int s 0/0.1 (F) East(config-if)#ip summary-address eigrp 25 10.2.0.0 255.255.252.0 West(config)# int s 0/0.1 (G) Wast(config-if)#ip summary-address eigrp 25 10.3.0.0 255.255.252.0
* Defaultly EIGRP uses %50 of the interface bandwidth and it is divided to neighbour count.
HO(config)#interface s0/0.1 HO(config-if)#ip bandwidth-percent eigrp 25 80
HO Router:
HO(config)#key chain EIGRP_KEYS HO(config-keychain)#key 1 HO(config-keychain-key)#key-string cisco1 HO(config-keychain-key)#accept –lifetime 00:00:00 1 Jan 2010 00:00:00 1 Feb 2010 HO(config-keychain-key)#send –lifetime … HO(config-keychain)#key 2 HO(config-keychain-key)#key-string cisco2 HO(config-keychain-key)#accept –lifetime 00:00:00 28 Jan 2010 infinite HO(config-keychain-key)#send –lifetime …
HO(config)#interface s0/0.1 HO(config-if)#ip authentication made eigrp 25 md5 HO(config-if)# ip authentication eigrp 25 EIGRP_KEYS
This is how the question 4 is answered.”Key String” refers to the password given, if the key-strings don’t match no neighborship can be established. ” Accept-Lifetime and “Send-Lifetime” refer to how long the created passwords will be sent and received “. Pay attention that EIGRP supports only MD5 authentication.
