ECS4660-28F_Management Guide-R03

C HAPTER 20 | Unicast Routing
Configuring the Open Shortest Path First Protocol (Version 2)
– 795 –
Figure 489: AS Boundary Router
◆ Advertise Default Route
14
– The router can advertise a default
external route into the autonomous system (AS). (Options: Not Always,
Always; Default: Not Always)
■
Always – The router will advertise itself as a default external route
for the local AS, even if a default external route does not actually
exist. (To define a default route, see "Configuring Static Routes" on
page 753.)
■
NotAlways – It can only advertise a default external route into the
AS if it has been configured to import external routes through RIP
or static routes, and such a route is known. (See "Redistributing
External Routes" on page 807.)
◆ External Metric Type
14
– The external link type used to advertise the
default route. Type 1 route advertisements add the internal cost to the
external route metric. Type 2 routes do not add the internal cost
metric. When comparing Type 2 routes, the internal cost is only used as
a tie-breaker if several Type 2 routes have the same cost.
(Default: Type 2)
◆ Default External Metric
14
– Metric assigned to the default route.
(Range: 0-16777215; Default: 20)
The metric for the default external route is used to calculate the path
cost for traffic passed from other routers within the AS out through the
ASBR.
Redistribution of routing information from other protocols is controlled
by the Redistribute function (see page 807).
WEB INTERFACE
To configure general settings for OSPF:
1. Click Routing Protocol, OSPF, System.
2. Select Configure from the Action list.
3. Select a Process ID, and then specify the Router ID and other global
attributes as required. For example, by setting the Auto Cost to 10000,
the cost of using an interface is set to 10 for Gigabit ports, and 1 for 10
Gigabit ports.
4. Click Apply
AS 1
ASBR
AS 2
ASBR