Packet Types - H3C S9500E Series Configuration Manual

VF tracking
The AVF forwards packets destined to the MAC address of the AVF. If the uplink of the AVF fails
and no LVF is notified to take over the AVF's work, hosts (on the LAN) that take the MAC address
of the AVF as their gateway MAC address cannot access the external network.
You can solve this problem through the VF tracking function. You can monitor the uplink state by
using NQA and BFD, and establish the collaboration between the VF and the NQA or between
the VF and the BFD through the tracking function. When the uplink fails, the state of the monitored
track entry changes to negative, and the weight of the VF decreases by a specified value. After
that, a VF with a higher priority becomes the AVF and forwards packets.

Packet types

VRRP standard protocol mode defines only one type of packet: the VRRP advertisement. Only the
master in a VRRP group periodically sends VRRP advertisements. The backups do not send VRRP
advertisements.
VRRP load balancing mode defines four types of packets:
•
Advertisement: VRRP uses advertisements of the VRRP group state on the local router and the
VF that is in the active state. Both the master and the backups send VRRP advertisements
periodically.
•
Request: If a backup router is not a VF owner, it sends a request to the master for a virtual
MAC address.
•
Reply: After receiving a request, the master sends a reply to the backup router to allocate a
virtual MAC address. Upon receiving the reply, the backup router creates a VF
corresponding to the virtual MAC address, and then the backup router becomes the owner
of this VF.
•
Release: After a VF owner fails for a specified time, the router that takes over its
responsibility sends a release to notify the other routers in the VRRP group to delete the VF of
the failed VF owner.
The format of the four types of packets used in VRRP load balancing mode is similar to that of the
advertisement in VRRP standard protocol mode. The difference is that a packet used in load balancing
mode is appended with option fields, which carry information for load balancing.
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