OSPF

Hi i have configured ospf, between R1 and R2. connected those router with serial links. i want that,
 
1-R1 Should send routes to R2 via S0/0
2-R2 should send routes to R1 via S0/0
3-When S0/0 link goes down traffic should route from S0/1

below is my running cofig of both routes.

###########################################################################

R1# Current configuration : 1286 bytes

!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
!
resource policy
!
memory-size iomem 5
ip subnet-zero
!
!
ip cef
no ip domain lookup
no ip dhcp use vrf connected

!
no crypto isakmp ccm
!

interface Loopback1
 ip address 1.1.1.1 255.255.255.0
!
interface Loopback2
 ip address 2.2.2.2 255.255.255.0
!
interface Serial0/0
 ip address 11.11.11.11 255.255.255.0
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial0/1
 ip address 12.12.12.12 255.255.255.0
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial0/2
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial0/3
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
router ospf 5
 log-adjacency-changes
 network 1.1.1.0 0.0.0.255 area 0
 network 2.2.2.0 0.0.0.255 area 0
 network 11.11.11.0 0.0.0.255 area 0
 network 12.12.12.0 0.0.0.255 area 0
!
no ip http server
no ip http secure-server
ip classless

R1#show ip route ospf
     5.0.0.0/32 is subnetted, 1 subnets
O       5.5.5.5 [110/65] via 12.12.12.13, 00:11:54, Serial0/1
                [110/65] via 11.11.11.12, 00:11:54, Serial0/0
     6.0.0.0/32 is subnetted, 1 subnets
O       6.6.6.6 [110/65] via 12.12.12.13, 00:11:54, Serial0/1
                [110/65] via 11.11.11.12, 00:11:54, Serial0/0

###########################################################################

R2# Current configuration : 1290 bytes

!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
!
resource policy
!
memory-size iomem 5
ip subnet-zero
!
!
ip cef
no ip domain lookup
no ip dhcp use vrf connected
!

no crypto isakmp ccm
!
interface Loopback1
 ip address 5.5.5.5 255.255.255.255
!
interface Loopback2
 ip address 6.6.6.6 255.255.255.255
!
interface Serial0/0
 ip address 11.11.11.12 255.255.255.0
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial0/1
 ip address 12.12.12.13 255.255.255.0
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial0/2
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
interface Serial0/3
 no ip address
 shutdown
 serial restart-delay 0
 no dce-terminal-timing-enable
!
router ospf 5
 log-adjacency-changes
 network 5.5.5.0 0.0.0.255 area 0
 network 6.6.6.0 0.0.0.255 area 0
 network 11.11.11.0 0.0.0.255 area 0
 network 12.12.12.0 0.0.0.255 area 0
!
no ip http server
no ip http secure-server
ip classless


R2#show ip route ospf
     1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/65] via 12.12.12.12, 00:12:59, Serial0/1
                [110/65] via 11.11.11.11, 00:12:59, Serial0/0
     2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 12.12.12.12, 00:12:59, Serial0/1
                [110/65] via 11.11.11.11, 00:12:59, Serial0/0

#######################################################################


1-R1 Should send routes to R2 via S0/0
2-R2 should send routes to R1 via S0/0
3-When S0/0 link goes down of R1,R2  traffic should route from S0/1

thx


P-to-P.jpeg
pawanopensourceAsked:
Who is Participating?
 
SouljaCommented:
How about just adding both serials on each router part of a multilink bundle?
0
 
mwblszCommented:
as you can see, you have two ospf routes for each subnet in your routing table, to favor one of them, the only way is to wrist the "cost", ospf route cost is based on bandwidth, cost= 10000 0000/bandwith in bps, not sure how much BW you have on both serial link, I assume they are all T1s, then the cost will be 64, to favor one of them, you can lower the cost of one of them to be say 60, go to the interface configuration on both router, and use "ip ospf cost 60" to make it more favorable.

sincerely
0
 
rfc1180Commented:
router ospf 5
maximum-paths 1
0
 
rfc1180Commented:
interesting, I wanted to add more, not just the commands; you can use the cost command to influence traffic, however, the cost command is used for a different purpose: The cost (also called metric) of an interface in OSPF is an indication of the overhead required to send packets across a certain interface. The cost of an interface is inversely proportional to the bandwidth of that interface. A higher bandwidth indicates a lower cost.

Soulja has mentioned a great solution for the serial interfaces, if you can, and have control of both routers, it would be a better solution to bundle the 2 links together; however, both links would be used to send traffic, and would be no different than the solution that exists at the moment. Note, that if you change the maximum paths to one, there is convergence times to allow traffic to be re-routed; as OSPF is a link state protocol, reconvergence should be upto 1 second while traffic reroutes.

Billy
0
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