H3C Technologies H3C MSR 5600 - Manual (Page 17)

9
• 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 calculated as 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.
VF backup
The VFs corresponding to a virtual MAC address on different routers in the VRRP group back up one
another.
Figure 8 VF information
Figure 8 shows the VF table on each router in the VRRP group and how the VFs 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, respectively, for the virtual
MAC addresses. 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
packets sent to virtual MAC address 000f-e2ff-0011.
• The VF 1 instances on Router B and Router C have a priority of 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 packets destined for virtual MAC address
000f-e2ff-0011. If the two LVFs' priorities are the same, the LVF with a greater device MAC address
becomes the new AVF.
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.
VF timers
When the AVF on a router fails, the new AVF on another router creates a redirect timer and a timeout
timer for the failed AVF, as follows: