3Com SuperStack 4 Configuration Manual page 132

144 C 6: IP R
HAPTER OUTING
P O
ROTOCOL PERATION
Configuring OSPF Packet Authentication
OSPF supports simple authentication or MD5 authentication between neighboring
routers.
Perform the following configuration in Interface View:
Table 150 Configuring OSPF Packet Authentication
Operation
Specify a password for OSPF simple
text authentication
Cancel simple authentication on the
interface
Specify the key-id and key for OSPF
MD5 authentication
Disable the interface to use MD5
authentication
By default, the interface is not configured with either simple authentication or
MD5 authentication.
Configuring OSPF to Import Routes of Other Protocols
The dynamic routing protocols on the router can share 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
specify the route cost type, cost value and tag to overwrite the default route
receipt parameters (refer to
routes" on page 145).
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 routes describes how to select the route to the destinations beyond the
AS.
The external type-1 routes refer 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 routes type-2 refer to the imported EGP routes. Since these routes
typically have higher cost, 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 ASBR. So
in route cost calculation, the cost from the ASBR to the destination is considered
and the cost between the router and the ASBR is ignored. If the cost from the
Command
ospf authentication-mode simple
undo ospf authentication-mode simple
ospf authentication-mode md5
undo ospf authentication-mode md5
import-route
"Configuring Parameters for OSPF to Import External
password
key_id key
commands, you can