Configuration Guide User guide

1050 FastIron Configuration Guide
53-1002494-02
IPv4 point-to-point GRE tunnels
Configuration tasks for GRE tunnels
Brocade recommends that you perform the configuration tasks in the order listed in Table 179.
The following features are also supported on GRE tunnel interfaces:
• Naming the tunnel interface (CLI command port-name) – for configuration details, refer to
“Assigning a port name” on page 40.
• Changing the Maximum Transmission Unit (MTU) (CLI command ip mtu) – for configuration
details, refer to “Changing the MTU on an individual port” on page 975.
TABLE 179 Configuration tasks for GRE tunnels
Configuration tasks Default behavior For more information
Required tasks
1 Create a tunnel interface Not assigned “Creating a tunnel interface” on
page 1051
2 Configure the source address or source
interface for the tunnel interface
Not assigned “Configuring the source address or
source interface for a tunnel
interface” on page 1051
3 Configure the destination address of the
tunnel interface
Not assigned “Configuring the destination address
for a tunnel interface” on page 1052
4 Enable GRE encapsulation on the tunnel
interface
NOTE: Step 4 must be performed before step
6.
Disabled “Enabling GRE encapsulation on a
tunnel interface” on page 1052
5 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 “Tunnel loopback ports for GRE
tunnels” on page 1046
6 Configure an IP address for the tunnel
interface
Not assigned “Configuring an IP address for a
tunnel interface” on page 1054
7 If a route to the tunnel destination
(configured in Step 3) does not already
exist, create a static route and specify that
the route is through the tunnel interface.
Not assigned “Configuring a static route to a tunnel
destination” on page 1054
Optional tasks
1 Change the maximum transmission unit
(MTU) value for the tunnel interface
1476 bytes or
10194 bytes (jumbo
mode)
“Changing the MTU value for a tunnel
interface” on page 1055
2 Change the number of GRE tunnels
supported on the device
Support for 32 GRE
tunnels
“Changing the maximum number of
tunnels supported” on page 1055
3 Enable and configure GRE link keepalive
on the tunnel interface
Disabled “Configuring GRE link keepalive” on
page 1056
4 Change the Path MTU Discovery (PMTUD)
configuration on the GRE tunnel interface
Enabled “Configuring Path MTU Discovery
(PMTUD)” on page 1056
5 Enable support for IPv4 multicast routing Disabled “Enabling IPv4 multicast routing over
a GRE tunnel” on page 1057