Configuring the Default Gateways
Console> (enable)
Configuring the Default Gateways
The supervisor engine sends IP packets that are destined for other IP subnets to the default gateway
(typically, a router interface in the same network or subnet as the switch IP address). The switch does
not use the IP routing table to forward traffic from connected devices; the switch forwards only IP traffic
that is generated by the switch itself (for example, Telnet, TFTP, and ping).
In some cases, you might want to configure static IP routes in addition to default gateways. For
Note
information on configuring static routes, see the
page
You can define up to three default IP gateways. Use the primary keyword to make a gateway the primary
gateway. If you do not specify a primary default gateway, the first gateway that is configured is the
primary gateway. If you designate more than one gateway as primary, the last primary gateway that is
configured is the primary default gateway.
The switch sends all off-network IP traffic to the primary default gateway. If connectivity to the primary
gateway is lost, the switch attempts to use the backup gateways in the order that they were configured.
The switch sends periodic ping messages to determine whether each default gateway is up or down. If
connectivity to the primary gateway is restored, the switch resumes sending traffic to the primary
gateway.
The system automatically associates routes and gateways to the appropriate sc0 or sc1 in-band interface.
Note
To configure one or more default gateways, perform this task in privileged mode:
Task
Step 1
Configure a default IP gateway address for the
switch.
Step 2
(Optional) Configure additional default gateways
for the switch.
Step 3
Verify that the default gateways appear correctly
in the IP routing table.
To remove the default gateway entries, perform one of these tasks in privileged mode:
Task
Clear an individual default gateway entry.
Clear all default gateways and static routes.
This example shows how to configure three default gateways on the switch and verify the default
gateway configuration:
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
3-8
vlan 0 inet 0.0.0.0 netmask 0.0.0.0 broadcast 0.0.0.0
22-8.
Chapter 3
Configuring the Switch IP Address and Default Gateway
"Configuring Static Routes on the Switch" section on
Command
set ip route default gateway [metric] [primary]
set ip route default gateway [metric] [primary]
show ip route
Command
clear ip route default gateway
clear ip route all
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