HP 7000 dl Router manual Config-interface# Interface Configuration Mode

SROS Command Line Interface Reference Guide HDLC Command Set

mtu <size>

Use the mtu command to configure the maximum transmit unit (MTU) size for the active interface. Use the no form of this command to return to the default value.

Syntax Description

<size>	Configures the window size for transmitted packets. The valid ranges for the
	various interfaces are listed below:
	Ethernet	64 to 1500
	Virtual Frame Relay sub-interfaces	64 to 1520
	Virtual PPP interfaces	64 to 1500
	Loopback interfaces	64 to 1500
	HDLC	64 to 1520
Default Values
<size>	The default values for the various interfaces are listed below:
	Ethernet	1500
	Virtual Frame Relay sub-interfaces	1500
	Virtual PPP interfaces	1500
	Loopback interfaces	1500
	HDLC	1500
Command Modes
(config-interface)#	Interface Configuration Mode

Valid interfaces include: Ethernet (eth 0/1), virtual PPP interfaces (ppp 1), virtual HDLC interfaces (hdlc 1), virtual Frame Relay sub-interfaces (fr 1.20), tunnel interfaces (tunnel 1), and VLAN interface (vlan 1).

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 HDLC interface:

(config)#interface hdlc 1 (config-hdlc 1)#mtu 1200

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