Routing Table - Allied Telesis AT-8100L/8 User Manual

Chapter 104: Internet Protocol Version 4 Packet Routing

Routing Table

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The switch has a routing table of local and remote networks The local
networks are the routing interfaces on the VLANs on the switch. The
remote networks are static routes or routes learned through RIP. Each
remote route is uniquely identified in the table with the following
information:

The network address of the remote destination

The administrative distance

The metric

The IP address of the next hop
 The ID of the VLAN of the next hop
When the switch receives an IPv4 packet, it scans the routing table to find
the most specific route to the destination and then forwards the packet to
the next hop of the route. If the switch does not find a direct route to the
remote destination, and no default route exists, the switch discards the
packet and sends an ICMP message to that effect back to the source.
The switch advertises its routing table every thirty seconds from those
VLANs that have RIP. The time interval is adjustable with "TIMERS
BASIC" on page 1897. The switch also advertises its routing table and
resets the timer to zero whenever there is a change to the table, thereby
ensuring that the neighboring routers are immediately informed of updates
to the table.
Dynamic RIP routes are removed from the table when they are not kept up
to date (refreshed) by the neighboring routers. The metric of a route that is
not refreshed is increased to 16 to indicate an unreachable network.
Routes that are not updated after 180 seconds are deleted from the table.
The maximum storage capacity of the routing table in the switch is:
 Interface routes: 4094
 Interface and static routes: 4000
 Interface, static, and RIP routes: 4000