ip mtu
Syntax
ip mtu <VALUE>
Description
This command sets the MTU (maximum transmission unit) for an IP interface. This defines the largest IP packet that can be sent or received by the interface. The MTU has to account for 28 bytes of IP layer overhead, plus a GRE header (when defining a GRE tunnel). It must be larger than the MTU of the interface that the tunnel is using. Packets larger than the MTU are dropped.
The
no
form of this command sets the MTU to the default value of 1500 bytes.
Command context
config-gre-if
config-ip-if
Parameters
<VALUE>
Specifies the MTU in bytes. Range: 1280 to 9,192 bytes.
Authority
Administrators
Examples
Sets the MTU on GRE interface
33
to
1300 bytes.
switch(config)# interface tunnel 33 mode gre ipv4 switch(config-gre-if)# mtu 1300
Sets the MTU on GRE interface
33
to the default value.
switch(config)# interface tunnel 33 mode gre ipv4 switch(config-gre-if)# ip mtu
Sets the MTU on IPv6 in IPv4 tunnel
27
to
1000 bytes.
switch(config)# interface tunnel 27 mode ip 6in4 switch(config-ip-if)# mtu 1000
Sets the MTU onIPv6 in IPv4 tunnel
27
to the default value.
switch(config)# interface tunnel 27 mode ip 6in4 switch(config-ip-if)# ip mtu