Enterprise NOS Extensions to VRRP
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G8264 Application Guide for ENOS 8.4
This section describes VRRP enhancements that are implemented in ENOS.
ENOS supports a tracking function that dynamically modifies the priority of a
VRRP router, based on its current state. The objective of tracking is to have,
whenever possible, the master bidding processes for various virtual routers in a
LAN converge on the same switch. Tracking ensures that the selected switch is the
one that offers optimal network performance. For tracking to have any effect on
virtual router operation, preemption must be enabled.
ENOS can track the attributes listed in Table
Table 44.
VRRP Tracking Parameters
Parameter
Number of IP interfaces on the
switch that are active ("up")
trackingpriorityincrement
interfaces
Number of active ports on the same
VLAN
trackingpriorityincrement
ports
Number of virtual routers in master
mode on the switch
trackingpriorityincrement
virtualrouters
Next hop tracking
virtualrouter <x> nexthop
<IP address> [ICMP|ARP]
[<interval>] [<retries>]
Each tracked parameter has a user‐configurable weight associated with it. As the
count associated with each tracked item increases (or decreases), so does the VRRP
routerʹs priority, subject to the weighting associated with each tracked item. If the
priority level of a standby is greater than that of the current master, then the
standby can assume the role of the master.
See "Configuring the Switch for Tracking" on page
configure the switch for tracking VRRP priority.
44 (Router VRRP mode):
Description
Helps elect the virtual routers with the
most available routes as the master. (An IP
interface is considered active when there
is at least one active port on the same
VLAN.) This parameter influences the
VRRP routerʹs priority in virtual interface
routers.
Helps elect the virtual routers with the
most available ports as the master. This
parameter influences the VRRP routerʹs
priority in virtual interface routers.
Useful for ensuring that traffic for any
particular client/server pair is handled by
the same switch, increasing routing
efficiency. This parameter influences the
VRRP routerʹs priority in virtual interface
routers.
A health check mechanism that is used to
track the next hop. This parameter
influences the VRRP router's priority
based on the availability of the next hop.
617 for an example on how to