Alcatel-Lucent 7750 SR OS - Manual (Page 98)

Configuration Commands
Page 98 7750 SR OS Router Configuration Guide
allow-directed-broadcasts
Syntax [no] allow-directed-broadcasts
Context config>router>interface ip-int-name
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.
When enabled, a frame destined to the local subnet on this IP interface is sent as a subnet broadcast
out this interface. NOTE: Allowing directed broadcasts is a well-known mechanism used for denial-
of-service attacks.
By default, directed broadcasts are not allowed and are discarded at this egress IP interface.
The no form of the command disables directed broadcasts forwarding out of the IP interface.
Default no allow-directed-broadcasts - directed broadcasts are dropped.
arp-timeout
Syntax arp-timeout seconds
no arp-timeout
Context config>router>interface ip-int-name
Description This command configures the minimum time, in seconds, an ARP entry learned on the IP interface is
stored in the ARP table. ARP entries are automatically refreshed when an ARP request or gratuitous
ARP is seen from an IP host. Otherwise, the ARP entry is aged from the ARP table. If the arp-
timeout value is set to 0 seconds, ARP aging is disabled.
The no form of the command reverts to the default value.
Default 14400 seconds (4 hours)
Parameters seconds — The minimum number of seconds a learned ARP entry is stored in the ARP table,
expressed as a decimal integer. A value of 0 specifies that the timer is inoperative and learned
ARP entries will not be aged.
Values 0 — 65535
bfd
Syntax bfd transmit-interval [receive receive-interval] [multiplier multiplier]
no bfd
Context config>router> interface
Description This command specifies the bi-directional forwarding detection (BFD) parameters for the associated
IP interface. If no parameters are defined the default value are used.