Rdp Interfaces - Alcatel OmniSwitch 6624 Network Configuration Manual

RDP Overview

RDP Interfaces

An RDP interface is created by enabling RDP on a VLAN router IP address. Once enabled, the RDP inter-
face becomes active and joins the all-routers IP multicast group (224.0.0.2). The interface then transmits 3
initial router advertisement messages at random intervals that are no greater than 16 seconds apart. This
process occurs upon activation to increase the likelihood that end hosts will quickly discover this router.
After an RDP interface becomes active and transmits its initial advertisements, subsequent advertisements
are transmitted at random intervals that fall between a configurable range of time. This range of time is
defined by specifying a maximum and minimum advertisement interval value. See
tisement Interval" on page 14-9
intervals, the risk of system overload is reduced as advertisements from other routers on the same link are
not likely to transmit at the same time.
It is important to note that advertisements are only transmitted on RDP interfaces if the following condi-
tions are met:
The RDP global status is enabled on the switch.
•
An IP interface exists and is in the enabled state.
•
An RDP interface exists and is in the enabled state.
•
Either VRRP is disabled or if VRRP is enabled, there is one or more Master IP addresses for the
•
VLAN. If VRRP is enabled and if there are no Masters IP addresses, router advertisements are not sent
on the VLAN. (See
The router advertisement is a multicast packet sent to the all-systems IP multicast group (224.0.0.1) or the
broadcast address. If VRRP is enabled, the message should be filled with IP addresses obtained from
VRRP Master IP address list; otherwise the IP address of this VLAN is used.
Note that RDP is not recommended for detecting neighboring router failures, referred to as black holes, in
the network. However, it is possible to use RDP as a supplement for black hole detection by setting RDP
interface advertisement interval and lifetime values to values lower than the default values for these
parameters. See "Defining the Advertisement Interval" on page 14-9
time" on page 14-10
page 14-6
for more information. Because advertisements are transmitted at random
Chapter 16, "Configuring VRRP,"
for more information.
OmniSwitch 6624/6648 Network Configuration Guide
"Defining the Adver-
for more information.)
and "Setting the Advertisement Life-
Configuring RDP
April 2004