3Com 3500 manual Ip ospf policy modify, Modifies an existing Ospf routing policy

598CHAPTER 19: OPEN SHORTEST PATH FIRST (OSPF)

ip ospf policy modify

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9400

3900

9300

Modifies an existing OSPF routing policy.

Valid Minimum Abbreviation

ip o po m

Important Considerations

■The system assigns an index number to each policy and takes into account all route policies, Routing Information Protocol (RIP) and OSPF, that are set on the system.

■There are certain conditions associated with import and export policies. See the Implementation Guide for your system for more information.

■Your system has one unified IP routing table. Routing policies allow you to control the flow of information among the network, the protocols, and the routing tables on your system.

■There are two classes of routing policies:

■Import policies — Control which OSPF non-self-originated external routes are stored in the routing table. OSPF import policies control only what the local router uses. They do not affect the propagation of non-self-originated external routes to other routers.

■Export policies — Used on OSPF boundary routers to control which self-originated external routing updates are placed in the link-state database for propagation over the network. In this way, export policies govern what other routers learn with regard to the local boundary router’s self-originated information.

■You can set up an IP RIP or OSPF import or export policy to accept or advertise the default route, as long as the default route exists in the routing table. When you define a policy, you are always prompted for the route subnet mask after the route address, even though you specify the wildcard route address of 0.0.0.0.

Specify a route subnet mask as follows:

■If you want the wildcard subnet mask for all routes, use the default subnet mask (0.0.0.0).

■If you want the default route (not all routes), enter 255.255.255.255.

■For more information about IP routing policies, see the Implementation Guide for your system.