Alcatel-Lucent 7750 SR OS Service Manual page 731

In SRRP, a single SRRP instance is tied to a group IP interface. The group IP interface is contained
directly within a subscriber IP interface context and thus directly associated with the subscriber
subnets on the subscriber IP interface. The SRRP instance is also indirectly associated with any
subscriber subnets tied to the subscriber interface through wholesale/retail VPRN configurations.
With the directly-associated and the indirectly-associated subscriber interface subnets, a single SRRP
instance can manage hundreds of SRRP gateway IP addresses. This automatic subnet association to
the SRRP instance is different from VRRP where the redundant IP address is defined within the
VRRP context.
Defining an SRRP gateway IP address on a subscriber subnet is not optional when the subnet is
associated with a group IP interface with SRRP enabled. Enabling SRRP (no shutdown) will fail if
one or more subscriber subnets do not have an SRRP gateway IP address defined. Creating a new
subscriber subnet without an SRRP gateway IP address defined will fail when the subscriber subnet is
associated with a group IP interface with an active SRRP instance. Once SRRP is enabled on a group
interface, the SRRP instance will manage the ARP response and routing behavior for all subscriber
hosts reachable through the group IP interface.
The no form of the command removes the address from a subscriber subnet. The address command
for the specific subscriber subnet must be executed without the gw-address parameter. To succeed,
all SRRP instances associated with the subscriber subnet must removed or shutdown.
Parameters
ip-address/mask | ip-address netmask — Specifies the address space associated with the subscriber
gw-ip-address ip-address — Specifies a separate IP address within the subnet for SRRP routing
allow-directed-broadcasts
Syntax [no] allow-directed-broadcasts
Context config>service>ies>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 on another IP interface. The allow-directed-broadcasts command on an IP interface enables
7750 SR OS Services Guide
subnet
purposes. This parameter must be followed by a valid IP interface that exists within the
subscriber subnet created by the address command. The defined gateway IP address cannot
currently exist as a subscriber host (static or dynamic). If the defined ip-address already exists as
a subscriber host address, the address command will fail. The specified ip-address must be
unique within the system.
The gw-address parameter may be specified at anytime. If the subscriber subnet was created
previously, executing the address command with a gw-address parameter will simply add the
SRRP gateway IP address to the existing subnet.
If the address command is executed without the gw-address parameter when the subscriber
subnet is associated with an active SRRP instance, the address will fail. If the SRRP instance is
inactive or removed, executing the address command without the gw-address parameter will
remove the SRRP gateway IP address from the specified subscriber subnet.
If the address command is executed with a new gw-address, all SRRP instances currently
associated with the specified subscriber subnet will be updated with the new SRRP gateway IP
address.
Internet Enhanced Services
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