Unicast Routing
20-16
20
•
Area Border Router
21
– Indicates if this
router connects directly to networks in two
or more areas. An area border router runs
a separate copy of the Shortest Path First
algorithm, maintaining a separate routing
database for each area.
•
AS Boundary Router
22
Autonomous System Boundary
Router – 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)
•
RFC1583 Compatible
– If one or more routers in a routing domain are using early
Version 2 of OSPF, this router should use RFC 1583 (early OSPFv2) 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)
When RFC 1583 compatibility is enabled, only cost is used when choosing among
multiple AS-external LSAs advertising the same destination. When disabled,
preference is based on type of path, using cost only to break ties (see RFC 2328).
If there any OSPF routers in an area exchanging summary information
(specifically, ABRs) which have not been upgraded to OSPFv2 (RFC 2328),
RFC 1583 should be used on the newly upgraded OSPFv2 routers to ensure
compatibility with routers still running older OSPFv2 code.
•
SPF Hold Time
– The hold time between making two consecutive shortest path
first (SPF) calculations. (Range: 0-65535 seconds; Default: 10 seconds)
Setting the SPF holdtime to 0 means that there is no delay between consecutive
calculations.
•
Area Numbers
21
– The number of configured areas attached to this router.
Default Route Information –
•
Originate Default Route
22
– 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)
When this feature is used to redistribute routes into a routing domain (that is, an
Autonomous System), this router automatically becomes an Autonomous System
Boundary Router (ASBR). This allows the router to exchange routing information
with boundary routers in other autonomous systems to which it may be attached.
If a router is functioning as an ASBR, then every other router in the autonomous
system can learn about external routes from this device.
22. CLI - These are configured with the
default-information originate
command (page 42-21).
backbone
area,
stub,
NSSA
ABR
AS 1
ASBR
AS 2
ASBR
Summary of Contents for 8926EM
Page 6: ...ii ...
Page 34: ...Getting Started ...
Page 44: ...Introduction 1 10 1 ...
Page 62: ...Initial Configuration 2 18 2 ...
Page 64: ...Switch Management ...
Page 76: ...Configuring the Switch 3 12 3 ...
Page 118: ...Basic Management Tasks 4 42 4 ...
Page 164: ...User Authentication 6 28 6 ...
Page 176: ...Access Control Lists 7 12 7 ...
Page 284: ...Quality of Service 14 8 14 ...
Page 294: ...Multicast Filtering 15 10 15 ...
Page 300: ...Domain Name Service 16 6 16 ...
Page 310: ...Dynamic Host Configuration Protocol 17 10 17 ...
Page 320: ...Configuring Router Redundancy 18 10 18 ...
Page 344: ...IP Routing 19 24 19 ...
Page 356: ...Unicast Routing 20 12 20 Web Click Routing Protocol RIP Statistics Figure 20 5 RIP Statistics ...
Page 386: ...Unicast Routing 20 42 20 ...
Page 388: ...Command Line Interface ...
Page 400: ...Overview of the Command Line Interface 21 12 21 ...
Page 466: ...SNMP Commands 24 16 24 ...
Page 520: ...Access Control List Commands 26 18 26 ...
Page 546: ...Rate Limit Commands 30 2 30 ...
Page 612: ...VLAN Commands 34 24 34 ...
Page 626: ...Class of Service Commands 35 14 35 ...
Page 670: ...DHCP Commands 39 16 39 ...
Page 716: ...IP Interface Commands 41 36 41 ...
Page 768: ...IP Routing Commands 42 52 42 ...
Page 770: ...Appendices ...
Page 791: ......