Master And Backup Virtual Router; Virtual Interface Router; Vrrp Operation - Lenovo RackSwitch G8264CS Application Manual

Master and Backup Virtual Router

Virtual Interface Router

VRRP Operation

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Within each virtual router, one VRRP router is selected to be the virtual router
master. See "Selecting the Master VRRP Router" on page
the selection process.
Note: If the IPv4 address owner is available, it will always become the virtual
router master.
The virtual router master forwards packets sent to the virtual router. It also
responds to Address Resolution Protocol (ARP) requests sent to the virtual routerʹs
IPv4 address. Finally, the virtual router master sends out periodic advertisements
to let other VRRP routers know it is alive and its priority.
Within a virtual router, the VRRP routers not selected to be the master are known
as virtual router backups. If the virtual router master fails, one of the virtual router
backups becomes the master and assumes its responsibilities.
At Layer 3, a Virtual Interface Router (VIR) allows two VRRP routers to share an IP
interface across the routers. VIRs provide a single Destination IPv4 (DIP) address
for upstream routers to reach various destination networks, and provide a virtual
default Gateway.
Note: Every VIR must be assigned to an IP interface, and every IP interface must
be assigned to a VLAN. If no port in a VLAN has link up, the IP interface of that
VLAN is down, and if the IP interface of a VIR is down, that VIR goes into INIT
state.
Only the virtual router master responds to ARP requests. Therefore, the upstream
routers only forward packets destined to the master. The master also responds to
ICMP ping requests. The backup does not forward any traffic, nor does it respond
to ARP requests.
If the master is not available, the backup becomes the master and takes over
responsibility for packet forwarding and responding to ARP requests.
526 for an explanation of
Chapter 33: Virtual Router Redundancy Protocol
525