Cisco Systems 3750E 用户手册
42-51
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02
Chapter 42 Configuring IP Multicast Routing
Configuring Advanced DVMRP Interoperability Features
To re-enable auto summarization, use the ip dvmrp auto-summary interface configuration command.
Adding a Metric Offset to the DVMRP Route
By default, the switch increments by one the metric (hop count) of a DVMRP route advertised in
incoming DVMRP reports. You can change the metric if you want to favor or not favor a certain route.
incoming DVMRP reports. You can change the metric if you want to favor or not favor a certain route.
For example, a route is learned by multilayer switch A, and the same route is learned by multilayer
switch B with a higher metric. If you want to use the path through switch B because it is a faster path,
you can apply a metric offset to the route learned by switch A to make it larger than the metric learned
by switch B, and you can choose the path through switch B.
switch B with a higher metric. If you want to use the path through switch B because it is a faster path,
you can apply a metric offset to the route learned by switch A to make it larger than the metric learned
by switch B, and you can choose the path through switch B.
Beginning in privileged EXEC mode, follow these steps to change the default metric. This procedure is
optional.
optional.
To return to the default setting, use the no ip dvmrp metric-offset interface configuration command.
Step 5
show running-config
Verify your entries.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface interface-id
Specify the interface to be configured, and enter interface configuration
mode.
mode.
Step 3
ip dvmrp metric-offset [in | out]
increment
increment
Change the metric added to DVMRP routes advertised in incoming
reports.
reports.
The keywords have these meanings:
•
(Optional) in—Specifies that the increment value is added to
incoming DVMRP reports and is reported in mrinfo replies.
incoming DVMRP reports and is reported in mrinfo replies.
•
(Optional) out—Specifies that the increment value is added to
outgoing DVMRP reports for routes from the DVMRP routing
table.
outgoing DVMRP reports for routes from the DVMRP routing
table.
If neither in nor out is specified, in is the default.
For increment, specify the value that is added to the metric of a DVMRP
router advertised in a report message. The range is 1 to 31.
router advertised in a report message. The range is 1 to 31.
If the ip dvmrp metric-offset command is not configured on an
interface, the default increment value for incoming routes is 1, and the
default for outgoing routes is 0.
interface, the default increment value for incoming routes is 1, and the
default for outgoing routes is 0.
Step 4
end
Return to privileged EXEC mode.
Step 5
show running-config
Verify your entries.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.