Configuring Higher-Level Protocols Over S-Vlans; Configuring The Mtu Size For Bridged Ethernet - Juniper JUNOSE 11.1.X - LINK LAYER CONFIGURATION 4-7-2010 Configuration Manual

JUNOSe 11.1.x Link Layer Configuration Guide

Configuring Higher-Level Protocols over S-VLANs

The procedures for configuring IP, PPPoE, and MPLS protocols over S-VLANs on
bridged Ethernet interfaces are identical to the procedures for configuring these
protocols over VLANs on bridged Ethernet interfaces.
This section provides an example for configuring PPPoE interfaces over S-VLAN
subinterfaces configured on bridged Ethernet. For descriptions of the commands
used in this procedure, see "Configuring Higher-Level Protocols over VLANs" on
page 454.
To configure PPPoE over S-VLAN over a bridged Ethernet interface:
1.
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Configuring the MTU Size for Bridged Ethernet

You can use the bridge1483 mtu command to configure a nondefault maximum
transmission unit (MTU) size, in bytes, for a bridged Ethernet interface. The default
MTU size for a bridged Ethernet interface is 1518 bytes.
Because you configure a bridged Ethernet interface over an ATM 1483 subinterface,
the MTU size set with the bridge1483 mtu command is limited by the MTU set for
the underlying ATM 1483 subinterface. As a result, the bridge1483 mtu command
requires you to configure an MTU size for the bridged Ethernet interface that does
not exceed the maximum allowable MTU size for the underlying ATM 1483
subinterface, 9180 bytes.
The configured MTU size for an interface is referred to as its administrative MTU, and
the MTU size at which the interface actually operates is referred to as its operational
460
Configuring the MTU Size for Bridged Ethernet
Follow the steps in "Configuring S-VLAN Subinterfaces over Bridged Ethernet"
on page 458 to configure the S-VLAN subinterface.
Create a PPPoE major interface on the S-VLAN subinterface.
host1(config-subif)#pppoe
Exit the subinterface context.
host1(config-subif)#exit
Create a PPPoE subinterface by adding a subinterface number to the interface
identification command.
host1(config)#pppoe subinterface atm 3/1.1.1.1
Specify PPP as the encapsulation method on the interface.
host1(config-subif)#encapsulation ppp
Assign an IP address and mask to the interface.
host1(config-subif)#ip address 10.1.2.3 255.255.255.255