3Com Switch 4800G 24-Port - Configuring OSPF Network Optimization

300 CHAPTER 28: OSPF CONFIGURATION
Configuring OSPF Route
Redistribution
Follow these steps to configure OSPF route redistribution:
n
■ Using the import-route command cannot redistribute a default external
route. To do so, you need to use the default-route-advertise command.
■ The default-route-advertise summary cost command is applicable only to
VPN, and the default route is redistributed in a Type-3 LSA. The PE router will
advertise the default route to the CE router. The switch does not support this
command currently because the switch does not support VPN.
■ By filtering redistributed routes, OSPF adds only routes, which are not filtered
out, into Type-5 LSAs or Type-7 LSAs for advertisement.
■ You can configure default parameters such as the cost, upper limit, tag and
type for redistributed routes. Tags are used to identify information related to
protocols. For example, when redistributing BGP routes, OSPF uses AS IDs as
route tags.
Configuring OSPF
Network Optimization
You can optimize your OSPF network in the following ways:
Configure a priority for
OSPF
preference [ ase ]
[ route-policy
route-policy-name ] value
Optional
The priority of OSPF internal routes
defaults to 10.
The priority of OSPF external
routes defaults to 150.
To do… Use the command… Remarks
To do… Use the command… Remarks
Enter system view system-view -
Enter OSPF view ospf [ process-id | router-id
router-id ] *
-
Configure OSPF to
redistribute routes from
another protocol
import-route protocol
[ process-id | allow-ibgp ]
[ cost cost | type type | tag
tag | route-policy
route-policy-name ]*
Required
Not configured by default
Configure OSPF to filter
redistributed routes before
advertisement
filter-policy { acl-number |
ip-prefix ip-prefix-name }
export [ protocol
[ process-id ]]
Optional
Not configured by default
Redistribute a default route default-route-advertise
[ always | cost cost | type
type | route-policy
route-policy-name ]*
default-route-advertise
summary cost cost
Optional
Not redistributed by default
Configure the default
parameters for redistributed
routes (cost, route number,
tag and type)
default { cost cost | limit
limit | tag tag | type type } *
Optional
By default, the default cost is
1, default upper limit of
routes redistributed per time
is 1000, default tag is 1 and
default type of redistributed
routes is Type-2.