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8-8
Cisco Nexus 7000 Series NX-OS Interfaces Configuration Guide, Release 5.x
OL-23435-03
Chapter 8 Configuring IP Tunnels
Configuring IP Tunnels
DETAILED STEPS
This example shows how to configure the tunnel interface to GRE and set the GRE tunnel keepalives:
switch# configure terminal
switch(config)# interface tunnel 1
switch(config-if)# tunnel mode gre ip
switch(config-if)# copy running-config startup-config
Enabling Path MTU Discovery
Use the tunnel path-mtu discovery command to enable path MTU discovery on a tunnel.
Assigning VRF Membership to a Tunnel Interface
You can add a tunnel interface to a VRF.
Command Purpose
Step 1
configure terminal
Example:
switch# configure terminal
switch(config)#
Enters configuration mode.
Step 2
interface tunnel number
Example:
switch(config)# interface tunnel 1
switch(config-if)#
Enters a tunnel interface configuration mode.
Step 3
tunnel mode gre ip
Example:
switch(config-if)# tunnel mode gre ip
Sets this tunnel mode to GRE
Step 4
show interfaces tunnel number
Example:
switch(config-if)# show interfaces
tunnel 1
(Optional) Displays the tunnel interface statistics.
Step 5
copy running-config startup-config
Example:
switch(config-if)# copy running-config
startup-config
(Optional) Saves this configuration change.
Command Purpose
tunnel path-mtu-discovery [age-timer min]
[min-mtu bytes]
Example:
switch(config-if)# tunnel
path-mtu-discovery 25 1500
Enables Path MTU Discovery (PMTUD) on a
tunnel interface. The parameters are as follows:
• mins—Number of minutes. The range is from
10 to 30. The default is 10.
• mtu-bytes—Minimum MTU recognized. The
range is from 92 to 65535. The default is 92.