ADTRAN 5000 Series - Manual (Page 880)

Command Reference Guide Loopback Interface Configuration Command Set
61200990L1-35E Copyright © 2005 ADTRAN 880
mtu
Use the mtu command to configure the maximum transmit unit size for the active interface. Use the no
form of this command to return to the default value.
Syntax Description
Configures the window size for transmitted packets. The valid ranges for the
various interfaces are listed below:
ATM interfaces
64 to 1520
Demand interfaces 64 to 1520
Ethernet interfaces 64 to 1500
FDL interfaces 64 to 256
HDLC interfaces 64 to 1520
Loopback interfaces 64 to 1500
Tunnel interfaces 64 to 18,190
Virtual Frame Relay sub-interfaces 64 to 1520
Virtual PPP interfaces 64 to 1500
Default Values
The default values for the various interfaces are listed below:
ATM interfaces
1500
Demand interfaces 1500
Ethernet interfaces 1500
FDL interfaces 256
HDLC interfaces 1500
Loopback interfaces 1500
Tunnel interfaces 1500
Virtual Frame Relay sub-interfaces 1500
Virtual PPP interfaces 1500
Applicable Platforms
This command applies to the NetVanta 300, 1000, 1000R, 2000, 3000, 4000, and 5000 and
Total Access 900 Series units.
Command History
Release 1.1 Command was introduced.
Functional Notes
OSPF will not become adjacent on links where the MTU sizes do not match. If router A and router B are
exchanging hello packets but their MTU sizes do not match, they will never reach adjacency. This is by
design and required by the RFC.
Usage Examples
The following example specifies an MTU of 1200 on the loopback interface:
(config)#interface loopback 1
(config-loop 1)#mtu 1200