Intel 480T, User Manual

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C H A P T E R 9 Enterprise Standby Router Protocol
switch to the routed backbone as part of the criteria for
determining the master/slave fail-over.
Two types of tracking are supported:
- VLAN – The number of active ports in a tracked VLAN
- IP route – The number of available IP routes
Other factors being equal, if one or more links to the routed
backbone fails for the master, ESRP fails-over to the switch that
has the most active ports associated with the routed backbone. If
there are no active ports associated with the tracked VLAN,
ESRP forces the switch to remain in slave state, because no
backbone connectivity is available.
• ESRP priority —This is a user-defined field. The range of the
priority value is 0 to 254; a higher number has higher priority. The
default priority setting is 0. A priority setting of 255 loses the
election and remains in standby mode.
• System MAC address —The switch with the higher MAC
address has priority.
ESRP Election Algorithms
You configure the switch to use one of five different election
algorithms to select the ESRP master. Each algorithm considers the
election factors in a different order of precedence, as follows:
•
ports_track_priority_mac
— Active ports, tracking
information, ESRP priority, MAC address (Default)
•
track_ports_priority_mac
— Tracking information, active
ports, ESRP priority, MAC address
•
priority_ports_track_mac
— ESRP priority, active ports,
tracking information, MAC address
•
priority_track_ports_mac
— ESRP priority, tracking
information, active ports, MAC address
•
priority_mac_only
— ESRP priority, MAC address
All switches in the ESRP network must use the same election
algorithm, otherwise loss of connectivity, broadcast storms, or other
unpredictable behavior may occur.