Last Updated on July 31, 2021 by Admin
You have a router that is running both OSPF and RIP. You have configured this router to perform mutual redistribution between the two protocols. The following conditions exist:
The S0/0 interface, which is configured for RIP, is routing for the 172.16.5.0/24 network.
The S0/1 interface, which is configured for OSPF, is routing for the 172.16.6.32/28 network.Users in the RIP domain are unable to connect to devices in the OSPF domain.What must be done to allow the OSPF routes to be redistributed into the RIP domain? (Choose two. Each correct answer is part of the solution.)
- Create a static route that points to 172.16.6.0/24 with a next hop of null0.
- Execute the passive-interface command on S0/0.
- Create a loopback address on the router
- Redistribute static routes into RIP.
The OSPF domain has a different mask than the RIP domain, and they are on the same major network. The OSPF domain’s mask is also longer than the RIP domain’s mask. Therefore, the RIP domain will not advertise routes learned from OSPF and redistributed into RIP. To solve this problem, you can create a static route to the major (classful) network 172.16.6.0/24, which includes all of the subnets in the OSPF domain, set the destination as null0, and then redistribute static routes into RIP. The following commands would enable this process:
router1(config)# ip route 172.16.5.0 255.255.255.0 null0 router1(config)# router rip router1(config-router)# redistribute static router1(config-router)# default metric 1
You should include the metric as well to ensure redistribution. This will allow the 172.16.5.0/24 network to be advertised to the RIP domain and, when the frames arrive at the null0 interface, will ensure the routing table of the router will have routes to the specific subnets of the OSPF domain.
You should not execute the passive-interface command. This would prevent the interface from advertising either RIP or OSPF routes, and would only allow RIP updates inbound. This would not solve the problem and will create additional problems when the router is unable to advertise RIP routes to the other routers in the RIP domain.
You should not create a loopback address on the router. Loopback addresses are logical addresses that can be created and used as the source of routing updates. Under normal circumstances, if routing updates are sourced from a physical interface and the interface goes down, the route will be removed from the routing tables. Since a loopback interface cannot go down, it provides the advantage of keeping a route in the tables even if the physical interface that services the route goes down. Loopback interfaces are of no help in solving the redistribution problem.
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