Motorola WiNG 5.4.2 System Reference Manual page 718

13 - 92 WiNG 5.4.2 Access Point System Reference Guide
ABR/ASBR
SPF
Stub Router
3. Select the Refresh
Lists Autonomous System Boundary Router (ASBR) data relevant to OSPF routing, including
the ASBR, ABR and ABR type. An Area Border Router (ABR) is a router that connects one or
more areas to the main backbone network. It is considered a member of all areas it is
connected to. An ABR keeps multiple copies of the link-state database in memory, one for each
area to which that router is connected An ASBR is a router connected to more than one
Routing protocol and exchanges routing information with routers in other protocols. ASBRs
typically also run an exterior routing protocol (for example, BGP), or use static routes, or both.
An ASBR is used to distribute routes received from other, external ASs throughout its own
autonomous system. Routers in other areas use ABR as next hop to access external addresses.
Then the ABR forwards packets to the ASBR announcing the external addresses.
Refer to the SPF field to assess the status of the shortest path forwarding (SFF) execution, last
SPF execution, SPF delay, SPF due in, SPF hold multiplier, SPF hold time, SPF maximum hold
time and SPF timer due flag.
The summary screen displays information relating to stub router advertisements and
shutdown and startup times. An OSPF stub router advertisement allows a new router into a
network without immediately routing traffic through the new router and allows a graceful shut
down or reload a router without dropping packets that are destined for other networks. This
feature introduces three configuration options that allow you to configure a router that is
running the OSPF protocol to advertise a maximum or infinite metric to all neighbors.
button to update the statistics counters to their latest values.