Overview of vrrpe – Brocade BigIron RX Series Configuration Guide User Manual
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BigIron RX Series Configuration Guide
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Overview of VRRPE
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Overview of VRRPE
VRRPE is Brocade’s proprietary version of VRRP that overcomes limitations in the standard
protocol. It is similar to VRRP, but differs in the following respects:
•
Owners and Backup:
•
VRRP has an Owner and one or more Backups for each virtual router. The Owner is the
router that has the IP address used for the virtual router. All the other routers supporting
the virtual router are Backups.
•
VRRPE does not use Owners. All routers are Backups for a given virtual router. The router
with the highest priority becomes the Master. If there is a tie for highest priority, the router
with the highest IP address becomes the Master. The elected Master owns the virtual IP
address and answers ping and ARP requests and so on.
•
Master and Backups:
•
VRRP – The “Owner” of the IP address of the VRID is the default Master and has the
highest priority (255). The precedence of the Backups is determined by their priorities.
The default Master is always the Owner of the IP address of the VRID.
•
VRRPE – The Master and Backups are selected based on their priority. You can configure
any of the BigIron RX devices to be the Master by giving it the highest priority. There is no
Owner.
•
Virtual Router’s IP address:
•
VRRP requires that the virtual router has an IP address that is configured on the Owner
router.
•
VRRPE requires only that the virtual router’s IP address be in the same subnet as an
interface configured on the VRID's interface. In fact, VRRPE does not allow you to specify
an 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 ID of the virtual router. The Master owns the Virtual MAC address.
•
VRRPE uses the interface’s actual MAC address as the source MAC address. The virtual
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:
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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’s 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’s priorities configured on the Backups. For example,
if the VRRP interface’s priority is 100 and a tracked interface with track priority 20 goes
down, the software changes the VRRP interface’s priority to 20.