Dell PowerConnect B-FCXs Configuration Manual page 831

Destination
1.1.0.0
Each IP route table entry contains the destination IP address and subnet mask and the IP address
of the next-hop router interface to the destination. Each entry also indicates the port attached to
the destination or the next-hop to the destination, the route IP metric (cost), and the type. The type
indicates how the IP route table received the route:
•
•
•
•
IP forwarding cache
The IP forwarding cache provides a fast-path mechanism for forwarding IP packets. The cache
contains entries for IP destinations. When a Layer 3 Switch has completed processing and
addressing for a packet and is ready to forward the packet, the device checks the IP forwarding
cache for an entry to the packet destination:
•
•
Each entry in the IP forwarding cache has an age timer. If the entry remains unused for ten
minutes, the software removes the entry. The age timer is not configurable.
Here is an example of an entry in the IP forwarding cache.
1
Each IP forwarding cache entry contains the IP address of the destination, and the IP address and
MAC address of the next-hop router interface to the destination. If the destination is actually an
interface configured on the Layer 3 Switch itself, as shown here, then next-hop information
indicates this. The port through which the destination is reached is also listed, as well as the VLAN
and Layer 4 QoS priority associated with the destination if applicable.
To display the IP forwarding cache, refer to
PowerConnect B-Series FCX Configuration Guide
53-1002266-01
NetMask
255.255.0.0
To display the IP route table, refer to
Switch only).
To configure a static IP route, refer to
only).
To clear a route from the IP route table, refer to
Switch only).
To increase the size of the IP route table for learned and static routes, refer to the section
"Displaying and modifying system parameter default settings"
-
For learned routes, modify the <ip-route> parameter.
-
For static routes, modify the <ip-static-route> parameter.
If the cache contains an entry with the destination IP address, the device uses the information
in the entry to forward the packet out the ports listed in the entry. The destination IP address is
the address of the packet final destination. The port numbers are the ports through which the
destination can be reached.
If the cache does not contain an entry and the traffic does not qualify for an entry in the
session table instead, the software can create an entry in the forwarding cache.
IP Address Next Hop
192.168.1.11 DIRECT
Gateway Port
99.1.1.2 1/1
"Displaying the IP route table"
"Configuring static routes"
"Clearing IP routes"
MAC
0000.0000.0000
"Displaying the forwarding cache"
Overview
Cost Type
2 R
on page 878 (Layer 3
on page 819 (Layer 3 Switch
on page 880 (Layer 3
on page 321:
Type Port Vlan Pri
PU n/a 0
on page 877.
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