Multihoming - Avaya 8800 Planning And Engineering

with the same peer, only one BFD session is established, and BFD shares session information
with both routing protocols.
You can enable BFD over data paths with specified OSPF neighbors, BGP neighbors, and
static routing next-hop addresses.
The Ethernet Routing Switch 8800/8600 supports BFD asynchronous mode, which sends BFD
control packets between two systems to activate and maintain BFD neighbor sessions. To
reach an agreement with its neighbor about how rapidly failure detection occurs, each system
estimates how quickly it can send and receive BFD packets.
A session begins with the periodic, slow transmission of BFD Control packets. When
bidirectional communication is achieved, the BFD session comes up. The switch only declares
a path as operational when two-way communication is established between systems.
After the session is up, the transmission rate of Control packets can increase to achieve
detection time requirements. If Control packets are not received within the calculated detection
time, the session is declared down. After a session is down, Control packet transmission
returns to the slow rate.
If a session is declared down, it cannot come back up until the remote end signals that it is
down (three-way handshake). A session can be kept administratively down by configuring the
state of AdminDown.
BFD restrictions
The Avaya Ethernet Routing Switch 8800/8600 supports up to 256 BFD sessions, however,
the number of BFD sessions plus the number of VLACP sessions cannot exceed 256.
The Ethernet Routing Switch 8800/8600 does not support the following IETF BFD options:
• Echo packets
• BFD over IPv6
• Demand mode
• authentication
The Ethernet Routing Switch 8800/8600 does not support:
• BFD on a VRRP virtual interface
• High Availability (HA) for BFD
The Ethernet Routing Switch 8800/8600 supports partial HA for BFD.
The Ethernet Routing Switch 8800/8600 also supports the modification of transmit and receive
intervals during an active BFD session.

Multihoming

Multihoming enables the Avaya Ethernet Routing Switch 8800/8600 to support clients or
servers that have multiple IP addresses associated with a single MAC address.
Planning and Engineering — Network Design
Link redundancy
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