CISCO Ospf-rip bidirectional redistribution

OSPF and RIP bidirectional redistribution experiments, the knowledge points include: Use Access-list and Route-map to filter the route, modify the ad value to prevent suboptimal path generation.

The old driver introduced the idea is: the network edge will often appear loops and suboptimal, the dynamic routing protocol itself will have its own anti-ring mechanism, so it is likely that the engineer design or configuration problems. In OSPF, we can kill the loop route directly (Route tag; filter tag). On the other hand, we optimize the network also need to do the corresponding route summary and route filtering.

1. Experimental topology:

Experimental Purpose: R4 3.1.1.1 access 1.1.1.1;4.1.1.1 via R3 through R2 access to R1 2.1.1.1. Filter out RIP's straight-link segments on R4, while preventing possible suboptimal paths.

2. Experimental steps:

Configure RIP and OSPF.

Configure route redistribution and ACL filtering.

3. First put out the experiment configuration:

3.1:rip

R1:

Router RIP

Version 2

Network 0.0.0.0

No auto-summary

R2:

Router RIP

Version 2

Redistribute OSPF metric 5 route-map o-to-r Network 10.0.0.0

No auto-summary

Different routing protocols calculate inconsistent metrics, so redistribution requires a standard metrics value, which is added under the redistribute command.

Default metrics parameter: Rip infinity (infinity) , any other route redistribution into the RIP must add Parameters , OSPF (BGP redistribution into OSPF is 1).

R3:

Router RIP

Version 2

Redistribute OSPF metric 5 route-map o-to-r (O-to-r is our custom route-map for filtering routes)

Network 10.0.0.0

No auto-summary

3.2:ospf

R2:

router OSPF 100

Router-id 2.2.2.2

Log-adjacency-changes

Redistribute RIP subnets Route-map r-to-o (RIP redistribution into RIP will need to declare subnets)

Network 10.10.24.0 0.0.0.255 Area 0

Distance 121 3.3.3.3 0.0.0.0 AD (modify ad values for detail routing to prevent suboptimal)

R3:

router OSPF 100

Router-id 3.3.3.3

Log-adjacency-changes

Redistribute RIP subnets Route-map r-to-o

Network 10.10.34.0 0.0.0.255 Area 0

Distance 121 2.2.2.2 0.0.0.0 AD

R4:

router OSPF 100

Router-id 4.4.4.4

Log-adjacency-changes

Network 3.1.1.0 0.0.0.255 Area 0

Network 4.1.1.0 0.0.0.255 Area 0

Network 10.10.24.0 0.0.0.255 Area 0

Network 10.10.34.0 0.0.0.255 Area 0

3.3:access-list;route-map:

R2 's access-list:

IP access-list Standard AD (release of destination address on RIP R1)

Permit 1.1.1.0

Permit 2.1.1.0

IP access-list Standard Deny (direct-connect segment filtering between routers on RIP)

Permit 10.10.12.0

Permit 10.10.13.0

IP access-list Standard o-to-r (for OSPF R4 3.1.1.1 redistribution to rip)

Permit 3.1.1.0

IP access-list standard R-to-o (same as)

Permit 1.1.1.0

R2 's Route-map:

Redistribute RIP subnets Route-map r-to-o

Redistribute OSPF metric 5 route-map O-to-r

Route-map R-to-o deny 5 (a map with multiple IDs in order from small to large)

Match IP address Deny (similar to Juniper's policy route match/then or If/then in the language)

Route-map R-to-o Permit 10 (entire R-to-o map first rejects RIP direct and allows R1 traffic last default behavior permit all)

Match IP Address R-to-o

Set Metric-type type-1

Route-map R-to-o Permit 20 (this logic and juniper are consistent, the default is deny all, so the last one is to write a permit and all)

Route-map O-to-r Permit 10

Match IP Address o-to-r

Set Metric 3

Route-map O-to-r Permit 20

3.4 Redistribution of routes:

R3 as an example: initially we redistribute the route directly, without making changes to the ad value, to view the routing table on the next R3.

Discover R3 's 1.1.1.1 and 2.1.1.1 routes are learned from R2, ad value 110 Next is 10.10.34.4 (R4). Analysis, R2 on the R1 traffic through RIP, redistribution into OSPF, OSPF default AD is 110 lower than RIP 120, so we need to R3 on the 2.1.1.1 for the route to modify a larger than 120 ad value.

RIP30 seconds update, so we can observe a change process:

4. Experimental phenomena:

R4 routing table:

R4 tracing routes:

R1 routes:

Track routing, not through? Bring the source address ping:

Just at work, often encounter a dead or alive Ping does not pass the situation, because the production network will have a variety of scene environment, it is best to develop the habit of ping with the source address. We have a direct address to deny in the R-to-o, not manually with the source address of the ping default is the routing table in the interface address, so it does not pass.

In the case of double export of business, it can be prepared by each other. The next experiment is to try PRB to achieve the main preparation.

CISCO Ospf-rip bidirectional redistribution