Brocade Communications Systems ICX 7250 series, Руководство по настройке

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VRRP master device abdication to backup device
To allow temporary control of a VRRP virtual router ID (VRID) to pass to a backup device, you can force the master device to abdicate to
a backup device by setting a lower priority.
Changing the priority of a VRRP master device allows a temporary abdication of the master device status to allow a backup device with a
higher priority to assume the master device role. By default, a VRRP owner device has a priority of 255, and the lower priority must be
set to a lower priority than at least one of the backup devices associated with the VRID.
When you change the priority of a VRRP owner, the change takes effect only for the current power cycle. The change is not saved to the
startup configuration file when you save the configuration, and it is not retained across a reload or reboot. Following a reload or reboot,
the VRRP owner again has priority 255.
NOTE
This feature supports IPv4 VRRP only. IPv6 VRRP, VRRP-E, and IPv6 VRRP-E are not supported.
ARP and VRRP control packets
Control packets for ARP and VRRP are handled differently by VRRP and VRRP-E.
Source MAC addresses in VRRP control packets
• VRRP—The virtual MAC address is the source.
• VRRP-E—The physical MAC address is the source.
VRRP control packets
• VRRP—Control packets are IP type 112 (reserved for VRRP), and they are sent to the VRRP multicast address 224.0.0.18.
• VRRP-E—Control packets are UDP packets destined to port 8888, and they are sent to the all-router multicast address
224.0.0.2.
Gratuitous ARP
When a VRRP device (either master or backup) sends an ARP request or a reply packet, the MAC address of the sender is the MAC
address of the router interface. One exception is if the owner sends an ARP request or a reply packet, in which case the MAC address of
the sender is the virtual MAC address. Only the master answers an ARP request for the virtual router IP address. Any backup router that
receives this request forwards the request to the master.
• VRRP—A control message is sent only once when the VRRP device assumes the role of the master VRRP device.
• VRRP-E—A control message is sent every 2 seconds by the VRRP-E master device because VRRP-E control packets do not
use the virtual MAC address.
Enabling an owner VRRP device
This task is performed on the device that is designated as the owner VRRP device because the IP address of one of its physical
interfaces is assigned as the IP address of the virtual router. For example, Router 1 is the owner VRRP device in the figure that follows.
For each VRRP session, there are master and backup routers, and the owner router is elected, by default, as the master router.
Enabling an owner VRRP device
Brocade FastIron Layer 3 Routing Configuration Guide
432 53-1003903-04