primary link between network 192.168.1.0/24 and 10.1.1.0/24 are thru R3, learn each others via EIGRP . R2 is a backup link in case the primary link is not available
*this is not a complete routing solution, this lab only looking from R1 point of view to reach 10.1.1.0/24
R1
interface Loopback1
ip address 192.168.1.1 255.255.255.0
!
interface Serial0/0
ip address 172.16.2.1 255.255.255.252
clock rate 56000
!
interface Serial0/1
ip address 172.16.1.1 255.255.255.252
clock rate 56000
!
router eigrp 1
network 10.0.0.0
network 172.16.1.0 0.0.0.3
network 192.168.1.0
no auto-summary
!
ip route 10.1.1.0 255.255.255.0 172.16.2.2 190
!
R2
interface FastEthernet0/0
ip address 10.1.1.2 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0
ip address 172.16.2.2 255.255.255.252
clock rate 56000
!
ip route 192.168.0.0 255.255.0.0 172.16.2.1
R3
interface FastEthernet0/0
ip address 10.1.1.1 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0
ip address 172.16.1.2 255.255.255.252
clock rate 56000
!
router eigrp 1
network 10.1.1.0 0.0.0.255
network 172.16.1.0 0.0.0.3
no auto-summary
-----------------------------------------------------
we've configure two route for R1 to reach 10.1.1.0
router eigrp 1
network 10.0.0.0
..
and
ip route 10.1.1.0 255.255.255.0 172.16.2.2 190
only one route with the lowest AD installed into the routing table
in this case, route from EIGRP (AD=90), static route(AD=190 as we defined)
R1#sh ip route
..
10.0.0.0/24 is subnetted, 1 subnets
D 10.1.1.0 [90/2195456] via 172.16.1.2, 00:05:22, Serial0/1
C 192.168.1.0/24 is directly connected, Loopback1
this what we call floating static route, by default AD for static route is 1, because we want this route to backup primary link w/ EIGRP in case it's not available.. we made it's AD higher than EIGRP AD
shutdown primary link to see the effect..
R1(config)#int ser 0/1
R1(config-if)#shut
R1#sh ip route
..
10.0.0.0/24 is subnetted, 1 subnets
S 10.1.1.0 [190/0] via 172.16.2.2
new route come into place.. via static with AD 190, thru 172.16.2.2 which is R2
next we'll discuss about Administrative Distance Vs Longest Prefix Match
