Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 118)

Configuration tasks for GRE tunnels TABLE 17
Configuration tasks Default behavior
Required tasks
Create a tunnel interface. Not assigned
Configure the source address or source interface for the tunnel interface. Not assigned
Configure the destination address of the tunnel interface. Not assigned
Enable GRE encapsulation on the tunnel interface.
NOTE
Step 4 must be performed before step 6.
Disabled
If packets need to be terminated in hardware, configure a tunnel loopback port for
the tunnel interface.
NOTE
Step 5 is not applicable to FCX devices.
Not assigned
Configure an IP address for the tunnel interface. Not assigned
If a route to the tunnel destination does not already exist, create a static route and
specify that the route is through the tunnel interface. Not assigned
Optional tasks
Change the maximum transmission unit (MTU) value for the tunnel interface. 1476 bytes or
9192 bytes (jumbo mode)
Change the number of GRE tunnels supported on the device. Support for 32 GRE tunnels
Enable and configure GRE link keepalive on the tunnel interface. Disabled
Change the Path MTU Discovery (PMTUD) configuration on the GRE tunnel
interface. Enabled
Enable support for IPv4 multicast routing. Disabled
The following features are also supported on GRE tunnel interfaces:
• Naming the tunnel interface (CLI command port-name ).
• Changing the Maximum Transmission Unit (MTU) (CLI command ip mtu ).
• Increasing the cost of routes learned on the port (CLI command ip metric ).
After configuring GRE tunnels, you can view the GRE configuration and observe the routes that use
GRE tunnels.
IP Configuration
118 FastIron Ethernet Switch Layer 3 Routing Configuration Guide
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