Microsoft ES4612 用户手册
IP Routing
3-225
3
• AS Boundary Router
20
– Allows
this router to exchange routing
information with boundary routers
in other autonomous systems to
which it may be attached. If a
router is enabled as an ASBR,
then every other router in the
autonomous system can learn
about external routes from this device. (Default: Disabled)
information with boundary routers
in other autonomous systems to
which it may be attached. If a
router is enabled as an ASBR,
then every other router in the
autonomous system can learn
about external routes from this device. (Default: Disabled)
• Rfc1583 Compatible – If one or more routers in a routing domain are using OSPF
Version 1, this router should use RFC 1583 (OSPFv1) compatibility mode to ensure
that all routers are using the same RFC for calculating summary route costs.
Enable this field to force the router to calculate summary route costs using RFC
1583. (Default: Disabled)
that all routers are using the same RFC for calculating summary route costs.
Enable this field to force the router to calculate summary route costs using RFC
1583. (Default: Disabled)
• SPF Hold Time (seconds) – The hold time between making two consecutive
shortest path first (SPF) calculations. (Range: 0-65535; Default: 10)
• Area Numbers
– The number of OSPF areas configured on this router.
Default Route Information –
• Originate Default Route
– Generates a default external route into an
autonomous system. Note that the AS Boundary Router field must be enabled,
and the Advertise Default Route field properly configured. (Default: Disabled)
and the Advertise Default Route field properly configured. (Default: Disabled)
• Advertise Default Route
the autonomous system (AS). (Options: NotAlways, Always; Default: NotAlways)
• Always – The router will advertise itself as a default external route for the AS,
• Always – The router will advertise itself as a default external route for the AS,
even if a default external route does not actually exist.
• NotAlways – It can only advertise a default external route into the AS if it has
been configured to import external routes via RIP or static configuration, and
such a route is known. (See “Redistributing External Routes” on page 3-242.)
such a route is known. (See “Redistributing External Routes” on page 3-242.)
• External Metric Type
– 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)
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
– The Metric assigned to the default route.
(Range: 1-65535; Default: 10)
20. CLI - These are configured with the default-information originate command (page 4-262).
AS 1
ASBR
AS 2
ASBR