Intel 480T User Manual page 162

C H A P T E R 9
Sales
VLAN
(master)
160
Enterprise Standby Router Protocol
OSPF or RIP
Figure 16: ESRP example using layer 2 and layer 3
redundancy
The VLAN Sales master switch, acting as master for VLAN Sales,
performs both layer 2 switching and layer 3 routing services for
VLAN Sales. The switch in standby mode for VLAN Sales
performs neither, thus preventing bridging loops in the VLAN. The
switch in standby mode does, however, exchange ESRP packets
with the VLAN Sales master switch.
There are four paths between the VLAN Sales switches. All the
paths are used to send ESRP packets, allowing for four redundant
paths for ESRP communication. The bottom switches, being ESRP-
aware, allow traffic within the VLAN to fail-over quickly, as they
will sense when a master/slave transition occurs and flush FDB
entries associated with the uplinks to the ESRP-enabled VLAN
Sales switches.
Sales
VLAN
(standby)
480t_019