Riverstone Networks WICT1-12 User Manual

Page 210

Advertising
background image

12-14 Riverstone Networks RS Switch Router User Guide Release 8.0

VRRP Configuration Notes

VRRP Configuration Guide

Skew-time = ( (256 - Priority) / 256 )

Therefore, the higher the priority, the faster a Backup router will detect that the Master is down. For example:

-

Default advertisement-interval = 1 second

-

Default Backup router priority = 100

-

Master-down-interval = time it takes a Backup to detect the Master is down

= (3 * adv-interval) + skew-time

= (3 * 1 second) + ((256 - 100) / 256)

= 3.6 seconds

If a Master router is manually rebooted, or if its interface is manually brought down, it will send a
special keep-alive advertisement that lets the Backup routers know that a new Master is needed
immediately.

A virtual router will respond to ARP requests with a virtual MAC address. This virtual MAC
depends on the virtual router ID:

virtual MAC address = 00005E:0001XX

where XX is the virtual router ID

This virtual MAC address is also used as the source MAC address of the keep-alive Advertisements transmitted
by the Master router.

If multiple virtual routers are created on a single interface, the virtual routers must have unique
identifiers. If virtual routers are created on different interfaces, you can reuse virtual router IDs .

For example, the following configuration is valid:

As specified in RFC 2338, a Backup router that has transitioned to Master will not respond to pings,
accept telnet sessions, or field SNMP requests directed at the virtual router's IP address.

Not responding allows network management to notice that the original Master router (i.e., the IP address owner)
is down.

ip-redundancy create vrrp 1 interface test-A

ip-redundancy create vrrp 1 interface test-B

Advertising