Service Manual

PVLAN Operations When One VLT Peer is Down
When a VLT port moves to the Admin or Operationally Down state on only one of the VLT nodes, the VLT Lag
is still considered to be up. All the PVLAN MAC entries that correspond to the operationally down VLT LAG are
maintained as synchronized entries in the device. These MAC entries are removed when the peer VLT LAG
also becomes inactive or a change in PVLAN configuration occurs.
PVLAN Operations When a VLT Peer is
Restarted
When the VLT peer node is rebooted, the VLAN membership of the VLTi link is preserved and when the peer
node comes back online, a verification is performed with the newly received PVLAN configuration from the
peer. If any differences are identified, the VLTi link is either added or removed from the VLAN. When the peer
node restarts and returns online, all the PVLAN configurations are exchanged across the peers. Based on the
information received from the peer, a bulk synchronization of MAC addresses that belong to spanned PVLANs
is performed.
During the booting phase or when the ICL link attempts to come up, a system logging message is recorded if
VLT PVLAN mismatches, PVLAN mode mismatches, PVLAN association mismatches, or PVLAN port mode
mismatches occur. Also, you can view these discrepancies if any occur by using the show vlt mismatch
command.
Interoperation of VLT Nodes in a PVLAN with
ARP Requests
When an ARP request is received, and the following conditions are applicable, the IP stack performs certain
operations.
• The VLAN on which the ARP request is received is a secondary VLAN (community or isolated VLAN).
• 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.
Virtual Link Trunking (VLT) 1171