Setting The Mtu For Demand Interfaces - HP 7102dl - ProCurve Secure Router Configuration Manual

Configuring Backup WAN Connections
Configuring Demand Routing for Backup Connections
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Setting the MTU for Demand Interfaces

When establishing a link, PPP peers must agree on how much data can be
contained in the information field of PPP frames. The value that communi-
cates this frame size is called the maximum receive unit (MRU). To increase
or decrease the value of the MRU, a PPP peer sets the MRU configuration
option in the Link Control Protocol (LCP). (LCP is one of the protocols in the
PPP suite. LCP is used to establish and control the PPP connection.)
To control the MRU that is negotiated between the two PPP peers, you
configure the maximum transmission unit (MTU), which defines the largest
size for a frame that the router can send over the connection. By default,
demand interfaces (which use PPP) have an MTU of 1500 bytes. If a frame
exceeds the MTU, it must be fragmented.
To successfully negotiate a PPP session, the two peers should be using the
same MTU.
To configure the MTU for all PPP connections used with demand routing,
enter:
ProCurve(config)# data-call mtu <number>
Replace <number> with a value between 64 and 1520.
To disable this setting for interfaces used with demand routing, enter:
ProCurve(config)# no data-call mtu