Alcatel-Lucent 7210 SAS M Service Manual page 613

allow-directed-broadcasts
Syntax [no] allow-directed-broadcasts
Context config>service>vprn>if
This command controls the forwarding of directed broadcasts out of the IP interface.
Description
A directed broadcast is a packet received on a local router interface destined for the subnet broadcast
address on 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 will be sent as a subnet
broadcast out this interface. Care should be exercised when allowing directed broadcasts as it is a
well-known mechanism used for denial-of-service attacks.
When disabled, directed broadcast packets discarded at this egress IP interface will be counted in the
normal discard counters for the egress SAP.
By default, directed broadcasts are not allowed and will be discarded at this egress IP interface.
The no form of this command disables the forwarding of directed broadcasts out of the IP interface.
no allow-directed-broadcasts — Directed broadcasts are dropped.
Default
local-proxy-arp
Syntax [no] local-proxy-arp
Context config>service>vprn>if
This command enables local proxy ARP. When local proxy ARP is enabled on an IP interface, the
Description
system responds to all ARP requests for IP addresses belonging to the subnet with its own MAC
address, and thus will become the forwarding point for all traffic between hosts in that subnet. When
local-proxy-arp is enabled, ICMP redirects on the ports associated with the service are automatically
blocked.
Default
no local-proxy-arp
loopback
Syntax [no] loopback
Context config>service>vprn>if
This command specifies that the associated interface is a loopback interface that has no associated
Description
physical interface. As a result, the associated interface cannot be bound to a SAP.
When using mtrace/mstat in a Layer 3 VPN context then the configuration for the VPRN should have
a loopback address configured which has the same address as the core instance's system address
(BGP next-hop).
7210 SAS M Services Guide
Virtual Private Routed Network Services
Page 613