Can VRRP heartbeat packets of an AR router be transmitted on Layer 2 only

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Can VRRP heartbeat packets of an AR router be transmitted on Layer 2 only?
The answer is Yes. At present, VRRP heartbeat packets cannot be forwarded on Layer 3, therefore VRRP advertisement packets cannot be transmitted transparently on the Layer 3 interface of the AR router as well.

Other related questions:
Does a bridge group on an AR router forward packets in Layer 2 or Layer 3

A bridge group on an AR router forwards packets in Layer 2.
Only interfaces with Layer-3 functions can be added to a bridge. However, a bridge forwards data in Layer 2.

Layer 2 transparent transmission mechanism for 802.1x protocol packets on S series switches
For S series switches (except the S1700), the Layer 2 transparent transmission mechanism for 802.1 protocol packets is as follows: 1. When an 802.1x protocol packet reaches the ingress node, the switch changes the multicast destination MAC address of the packet to a specified multicast MAC address. 2. After the MAC address of an 802.1x protocol packet is changed, the switch does not send the packet to the CPU for processing but directly forwards the packet on the Layer 2 network based on the configuration. 3. When the 802.1x protocol packet reaches the egress node, the switch restores the multicast destination MAC address of the packet to the standard multicast destination MAC address based on the mapping between the specified multicast destination MAC address and the 802.1x protocol configured on the switch.

Why VRRP heartbeat packets cannot be transmitted normally between VRRP master and backup devices when VRRP packets are sent in a Super-VLAN
For S series switches, by default, VRRP Advertisement packets of a super-VLAN are sent only to the sub-VLAN that has the smallest VLAN ID among all the sub-VLANs in Up state. VRRP heartbeat packets cannot be transmitted normally between VRRP master and backup devices when the link between them does not allow the first Sub-VLAN of the Super-VLAN. The vrrp advertise send-mode command can be used to cancel or configure the mode in which VRRP Advertisement packets of a super-VLAN are sent.

Can a bridge transparently transmit packets carrying VLAN tags
A bridge on an AR router supports the transparently transmission of VLAN packets. However, a VLANIF interface does not support the transparently transmission of VLAN packets. It is not recommended that the transparent transmission of VLAN packets should be performed on sub-interfaces.

VRRP heartbeat packet transmission for S series switches
For S series switches (S1700 excluded), in a VRRP + STP scenario, a VRRP group is configured on SwitchA and SwitchB. If the switch connected to a user cannot forward VRRP packets (for example, discarding unknown multicast packets is configured), or to prevent the link disconnectivity or instability for VRRP packets (heartbeat packets), a heartbeat line can be deployed between SwitchA and SwitchB to transmit VRRP packets.

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