Switch 7700 Configuration Guide

90 CHAPTER 5: ROUTING PROTOCOL OPERATION
Perform the following configuration in VLAN interface view.
By default, the interface is not configured with either simple authentication or
MD5 authentication.
Configure OSPF to Import the Routes of Other Protocols
The dynamic routing protocols on the router can share the routing information. As
far as OSPF is concerned, the routes discovered by other routing protocols are
always processed as the external routes of AS. In the import-route commands,
you can specify the route cost type, cost value and tag to overwrite the default
route receipt parameters (see
“Configure Parameters for OSPF to Import External
Routes”).
The OSPF uses the following four types of routes (in priority):
■ Intra-area route
■ Inter-area route
■ External route type 1
■ External route type 2
Intra-area and inter-area routes describe the internal AS topology whereas the
external route describes how to select the route to the destinations beyond the
AS.
The external type-1 routes refers to imported IGP routes (such as static route and
RIP). Since these routes are more reliable, the calculated cost of the external routes
is the same as the cost of routes within the AS. Also, this route cost and the route
cost of the OSPF itself are comparable. That is, the cost to reach the external route
type 1 equals the cost to reach the corresponding ASBR from the local router plus
the cost to reach the destination address of the route from the ASBR
The external type-2 routes refers to imported EGP routes. Since these routes have
lower credibility, OSPF assumes that the cost from the ASBR to reach the
destinations beyond the AS is higher than the cost from within the AS to the
ASBR. So in route cost calculation, the cost to reach the external type 2 route
equals the cost to the destination address of the route from the ASBR. If the two
values are equal, then the cost of the router to the corresponding ASBR is
considered.
Tab le 40 Configure OSPF Packet Authentication
Operation Command
Configure the interface to use
simple authentication
ospf authentication-mode simple password
Disable the interface to use simple
authentication
undo ospf authentication-mode simple
Configure the interface to use MD5
authentication
ospf authentication-mode md5 key_id key
Disable the interface to use MD5
authentication
undo ospf authentication-mode md5