Dell PowerConnect B-FCXs, Руководство по настройке

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PowerConnect B-Series FCX Configuration Guide 1107
53-1002266-01
Overview
31
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VRRPE does not use Owners. All routers are Backups for a given VRID. The router with the
highest priority becomes Master. If there is a tie for highest priority, the router with the
highest IP address becomes Master. The elected Master owns the virtual IP address and
answers ping and ARP requests and so on.
•
VRID's IP address:
•
VRRP requires that the VRID also be a real IP address configured on the VRID's interface
on the Owner.
•
VRRPE requires only that the VRID be in the same subnet as an interface configured on
the VRID's interface. In fact, VRRPE does not allow you to specify a real IP address
configured on the interface as the VRID IP address.
•
VRID's MAC Address:
•
VRRP source MAC is a virtual MAC address defined as 00-00-5E-00-01- <vrid> , where
<vrid> is the VRID. The Master owns the Virtual MAC address.
•
VRRPE uses the interface actual MAC address as the source MAC address. The MAC
address is
02-E0-52-
<hash-value> - <vrid> , where <hash-value> is a two-octet hashed value for the IP
address and <vrid> is the VRID.
•
Hello packets:
•
VRRP sends Hello messages to IP Multicast address 224.0.0.18.
•
VRRPE uses UDP to send Hello messages in IP multicast messages. The Hello packets use
the interface actual MAC address and IP address as the source addresses. The
destination MAC address is 01-00-5E-00-00-02, and the destination IP address is
224.0.0.2 (the well-known IP multicast address for “all routers”). Both the source and
destination UDP port number is 8888. VRRP messages are encapsulated in the data
portion of the packet.
•
Track ports and track priority:
•
VRRP changes the priority of the VRID to the track priority, which typically is lower than the
VRID priority and lower than the VRID priorities configured on the Backups. For example, if
the VRRP interface priority is 100 and a tracked interface with track priority 20 goes down,
the software changes the VRRP interface priority to 20.
•
VRRPE reduces the priority of a VRRPE interface by the amount of a tracked interface
priority if the tracked interface link goes down. For example, if the VRRPE interface priority
is 200 and a tracked interface with track priority 20 goes down, the software changes the
VRRPE interface priority to 180. If another tracked interface goes down, the software
reduces the VRID priority again, by the amount of the tracked interface track priority.
The most important difference is that all VRRPE routers are Backups. There is no Owner router.
VRRPE overcomes the limitations in standard VRRP by removing the Owner.
Figure 152 shows an example of a VRRPE configuration.