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LevelOne GTL-2691 User Manual

Page 636

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C

HAPTER

18

| General IP Routing

Displaying the Routing Table

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network, the routing table is updated, and those changes are

immediately reflected in the FIB.
The FIB is distinct from the routing table (or, Routing Information

Base – RIB), which holds all routing information received from routing

peers. The FIB contains unique paths only. It does not contain any

secondary paths. A FIB entry consists of the minimum amount of

information necessary to make a forwarding decision on a particular

packet. The typical components within a FIB entry are a network prefix,

a router (i.e., VLAN) interface, and next hop information.

The Routing Table (and

show ip route

command) only displays routes

which are currently accessible for forwarding. The router must be able

to directly reach the next hop, so the VLAN interface associated with
any dynamic or static route entry must be up. Note that routes

currently not accessible for forwarding, may still be displayed by using

the

show ip route database

command.

P

ARAMETERS

These parameters are displayed:

VLAN – VLAN identifier (i.e., configure as a valid IP subnet).

Destination IP Address – IP address of the destination network,

subnetwork, or host. Note that the address 0.0.0.0 indicates the

default gateway for this router.

Net Mask / Prefix Length – Network mask for the associated IP

subnet. This mask identifies the host address bits used for routing to

specific subnets.

Next Hop – The IP address of the next hop (or gateway) in this route.

Metric – Cost for this interface.

Protocol – The protocol which generated this route information.

(Options: Local, Static, RIP, OSPF, Others)

W

EB

I

NTERFACE

To display the routing table:

1.

Click IP, Routing, Routing Table.

2.

Select Show Information from the Action List.