Owner's Manual

Chapter 3. Managing the Switch | 71
NETGEAR 8800 User Manual
Network Login Continued Web-Based Authentication
Web-based Netlogin users continue to be authenticated after a failover.
Yes
Open Shortest Path First
(OSPF)
If you configure OSPF graceful restart, there is no traffic interruption.
However, after OSPF comes up after restart, OSPF re-establishes sessions
with its neighbors and relearns Link State Advertisements (LSAs) from all of
the neighbors. This causes an increase in control traffic onto the network.
If you do not configure graceful restart, the route manager deletes all OSPF
routes 1 second after the failover occurs, which results in a traffic
interruption in addition to the increased control traffic.
Yes
Open Shortest Path First
v3 (OSPFv3)
OSPFv3 does not support graceful restart, so the route manager deletes all
OSPFv3 routes 1 second after the failover occurs. This results in a traffic
interruption.
After OSPFv3 comes up on the new primary node, it relearns the routes
from its neighbors. This causes an increase in control traffic onto the
network.
No
Power over Ethernet
(PoE)
The PoE configuration is checkpointed to the backup node. This ensures
that if the backup takes over, all ports currently powered stay powered after
the failover and the configured power policies are still in place.
Yes
Protocol Independent
Multicast (PIM)
After a failover, all hardware and software caches are cleared and learning
from the hardware is restarted. This causes a traffic interruption since it is
the same as if the switch rebooted for all Layer
3 multicast traffic.
No
Routing Information
Protocol (RIP)
RIP does not support graceful restart, so the route manager deletes all RIP
routes 1 second after the failover occurs. This results in a traffic interruption
as well as an increase in control traffic as RIP

re-establishes its database.
No
Routing Information
Protocol next generation
(RIPng)
RIPng does not support graceful restart, so the route manager deletes all
RIPng routes 1 second after the failover occurs. This results in a traffic
interruption.
After RIPng comes up on the new primary node, it relearns the routes from
its neighbors. This causes an increase in control traffic onto the network.
No
Spanning Tree Protocol
(STP)
STP supports hitless failover including catastrophic failure of the primary
node without interruption. There should be no discernible network event
external to the switch. The protocol runs in lock step on both master and
backup nodes and the backup node is a hot spare that can take over at any
time with no impact on the network.
Yes
Virtual Router
Redundancy Protocol
(VRRP)
VRRP supports hitless failover. The primary node replicates VRRP PDUs to
the backup, which allows the primary and backup nodes to run VRRP in
parallel. Although both nodes receive VRRP PDUs, only the primary
transmits VRRP PDUs to neighboring switches and participates in VRRP.
Yes
Dynamic Host
Configuration Protocol
server
A DHCP server continues to maintain the IP addresses assigned to various
clients and the lease times even after failover. When a failover happens, all
the clients work as earlier.
Yes
Table 12. Protocol Support for Hitless Failover (Continued)
Protocol Behavior Hitless