Step 1 |
enable
Example:
|
Enables privileged EXEC mode.
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Step 2 |
configure
terminal
Example:
Router# configure terminal
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Enters global configuration mode.
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Step 3 |
interface
type number
Example:
Router(config)# interface tunnel 0
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Specifies the interface type and number, and enters interface configuration mode.
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Step 4 |
bandwidth
kb/s
Example:
Router(config-if)# bandwidth 1000
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Sets the current bandwidth value for an interface and communicates it to higher-level protocols.
Specifies the tunnel bandwidth to be used to transmit packets.
Use the
kb/s argument to set the bandwidth, in kilobits per second (kb/s).
Note
| This is only a routing parameter; it does not affect the physical interface. The default bandwidth setting on a tunnel interface is 9.6 kb/s. You should set the bandwidth on a tunnel to an appropriate value.
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Step 5 |
keepalive
[period [retries]]
Example:
Router(config-if)# keepalive 3 7
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(Optional) Specifies the number of times the device will continue to send keepalive packets without response before bringing the tunnel interface protocol down.
GRE keepalive packets may be configured either on only one side of the tunnel or on both.
If GRE keepalive is configured on both sides of the tunnel, the
period and
retries arguments can be different at each side of the link.
Note
| This command is supported only on GRE point-to-point tunnels.
|
Note
| The GRE tunnel keepalive feature should not be configured on a VRF tunnel. This combination of features is not supported.
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Step 6 |
tunnel
source
{ip-address |
interface-type
interface-number}
Example:
Router(config-if)# tunnel source GigabitEthernet 0/0/0
|
Configures the tunnel source.
Note
| The tunnel source IP address and destination IP addresses must be defined on two separate devices.
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Step 7 |
tunnel
destination
{hostname |
ip-address}
Example:
Router(config-if)# tunnel destination 10.0.2.1
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Configures the tunnel destination.
Note
| The tunnel source and destination IP addresses must be defined on two separate devices.
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Step 8 |
tunnel
key
key-number
Example:
Router(config-if)# tunnel key 1000
|
(Optional) Enables an ID key for a tunnel interface.
Use the
key-number argument to identify a tunnel key that is carried in each packet.
Tunnel ID keys can be used as a form of weak security to prevent improper configuration or injection of packets from a foreign source.
Note
| This command is supported only on GRE tunnel interfaces. We do not recommend relying on this key for security purposes.
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Step 9 |
tunnel
mode
gre {
ip |
multipoint}
Example:
Device(config-if)# tunnel mode gre ip
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Specifies the encapsulation protocol to be used in the tunnel.
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Step 10 |
ip
mtu
bytes
Example:
Device(config-if)# ip mtu 1400
|
(Optional) Sets the MTU size of IP packets sent on an interface.
If an IP packet exceeds the MTU set for the interface, the Cisco software will fragment it unless the DF bit is set.
All devices on a physical medium must have the same protocol MTU in order to operate.
For IPv6 packets, use the
ipv6
mtu command.
Note
| If the
tunnel
path-mtu-discovery command is enabled do not configure this command.
|
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Step 11 |
ip
tcp
mss
mss-value
Example:
Device(config-if)# ip tcp mss 250
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(Optional) Specifies the maximum segment size (MSS) for TCP connections that originate or terminate on a router.
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Step 12 |
tunnel
path-mtu-discovery
[age-timer {aging-mins |
infinite}]
Example:
Device(config-if)# tunnel path-mtu-discovery
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(Optional) Enables PMTUD on a GRE or IP-in-IP tunnel interface.
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Step 13 |
end
Example:
|
Exits interface configuration mode and returns to privileged EXEC mode.
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