H3C Technologies H3C MSR 50 - Manual (Page 72)

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{
On a router that does not own the VF, if the weight of the VF is higher than or equal to the lower
limit of failure, the priority of the VF is weight/(number of local AVFs +1).
{
If the weight of the VF is lower than the lower limit of failure, the priority of the VF is 0.
3. VF backup
The VFs corresponding to a virtual MAC address on different routers in the VRRP group back up
each other.
Figure 27 VF information
Figure 27 shows the VF table on each router in the VRRP group and how the routers back up one
another. The master, Router A, assigns virtual MAC addresses 000f-e2ff-0011, 000f-e2ff-0012,
and 000f-e2ff-0013 to itself, Router B, and Router C, and each router creates VF 1, VF 2, and VF
3 for the virtual MAC addresses, respectively. The VFs for the same virtual MAC address on
different routers back up one another. For example, the VF 1 instances on Router A, Router B, and
Router C back up one another.
{
The VF 1 instance on Router A (the VF 1 owner) has priority 255 and acts as the AVF to forward
the packets sent to virtual MAC address 000f-e2ff-0011.
{
The VF 1 instances on Router B and Router C have priority 255/(1 + 1), or 127. Because their
priorities are lower than the priority of the VF 1 instance on Router A, they act as LVFs to listen
to the state of the VF 1 instance on Router A.
{
When the VF 1 instance on Router A fails, the VF 1 instances on Router B and Router C elect the
one with higher priority as the new AVF to forward the packets destined for the virtual MAC
address 000f-e2ff-0011.
A VF always operates in preemptive mode. When an LVF finds its priority value higher than the
one advertised by the AVF, the LVF declares itself as the AVF.
4. VF timers
When the AVF on a router fails, the newly elected AVF on another router creates a redirect timer
and a timeout timer for the failed AVF.
{
Redirect Timer—Before this timer times out, the master still uses the virtual MAC address
corresponding to the failed AVF to respond to ARP/ND requests from the hosts. The VF owner