Reference Guide

● Layer 3 communication between secondary VLANs in a private VLAN is enabled by using the ip local-proxy-arp
command in INTERFACE VLAN configuration mode.
● The ARP request is not received on the ICL
Under such conditions, the IP stack performs the following operations:
● The ARP reply is sent with the MAC address of the primary VLAN.
● The ARP request packet originates on the primary VLAN for the intended destination IP address.
The ARP request received on ICLs are not proxied, even if they are received with a secondary VLAN tag. This behavior change
occurs because the node from which the ARP request was forwarded would have replied with its MAC address, and the current
node discards the ARP request.
Scenarios for VLAN Membership and MAC Synchronization With VLT
Nodes in PVLAN
The following table illustrates the association of the VLTi link and PVLANs, and the MAC synchronization of VLT nodes in a
PVLAN (for various modes of operations of the VLT peers):
Table 71. VLAN Membership and MAC Synchronization With VLT Nodes in PVLAN
VLT LAG Mode PVLAN Mode of VLT VLAN ICL VLAN
Membership
Mac
Synchronization
Peer1 Peer2 Peer1 Peer2
Trunk Trunk Primary Primary Yes Yes
Trunk Trunk Primary Normal No No
Trunk Trunk Normal Normal Yes Yes
Promiscuous Trunk Primary Primary Yes No
Trunk Access Primary Secondary No No
Promiscuous Promiscuous Primary Primary Yes Yes
Promiscuous Access Primary Secondary No No
Promiscuous Promiscuous Primary Primary Yes Yes
- Secondary
(Community)
- Secondary (Isolated) No No
Access Access Secondary
(Community)
Secondary (Isolated) No No
● Primary X ● Primary X
Yes Yes
Promiscuous Promiscuous Primary Primary Yes Yes
- Secondary
(Community)
- Secondary
(Community)
Yes Yes
- Secondary (Isolated) - Secondary (Isolated) Yes Yes
Promiscuous Trunk Primary Normal No No
Promiscuous Trunk Primary Primary Yes No
Virtual Link Trunking (VLT) 823