Alcatel-Lucent 7750 SR-OS, Configuration Manual

Page: 152 / 674

Router Interface Commands
Page 152 7750 SR OS Router Configuration Guide
parameter indicates the complete mask that will be used in a logical ‘AND’ function to derive the
local subnet of the IP address. Note that a mask of 255.255.255.255 is reserved for system IP
addresses.
Values 128.0.0.0 — 255.255.255.255
netmask — The subnet mask in dotted decimal notation.
Values 0.0.0.0 — 255.255.255.255 (network bits all 1 and host bits all 0)
broadcast { all-ones | host-ones } — The optional broadcast parameter overrides the default
broadcast address used by the IP interface when sourcing IP broadcasts on the IP interface. If no
broadcast format is specified for the IP address, the default value is
host-ones, which indictates a
subnet broadcast address. Use this parameter to change the broadcast address to all-ones or
revert back to a broadcast address of host-ones .
The all-ones keyword following the broadcast parameter specifies that the broadcast address
used by the IP interface for this IP address will be 255.255.255.255, also known as the local
broadcast.
The host-ones keyword following the broadcast parameter specifies that the broadcast address
used by the IP interface for this IP address will be the subnet broadcast address. This is an IP
address that corresponds to the local subnet described by the
ip-addr and the mask-length or
mask with all the host bits set to binary 1. This is the default broadcast address used by an IP
interface.
The broadcast parameter within the address command does not have a negate feature, which is
usually used to revert a parameter to the default value. To change the broadcast type to host-
ones after being changed to all-ones , the address command must be executed with the
broadcast parameter defined.
The broadcast format on an IP interface can be specified when the IP address is assigned or
changed.
This parameter does not affect the type of broadcasts that can be received by the IP interface. A
host sending either the local broadcast (
all-ones ) or the valid subnet broadcast address ( host-
ones ) will be received by the IP interface.
Default host-ones
Values all-ones , host-ones
allow-directed-broadcasts
Syntax [ no ] allow-directed-broadcasts
Context config>router>interface
Description This command enables the forwarding of directed broadcasts out of the IP interface.
A directed broadcast is a packet received on a local router interface destined for the subnet broadcast
address of another IP interface. The
allow-directed-broadcasts command on an IP interface enables
or disables the transmission of packets destined to the subnet broadcast address of the egress IP
interface.