Administrator Guide

• You cannot change the VLT LAG to a legacy LAG when it is part of proxy-gateway.
• You cannot change the link layer discovery protocol (LLDP) port channel interface to a legacy LAG when you enable a proxy gateway.
• Dell Networking recommends the vlt-peer-mac transmit command only for square VLTs without diagonal links.
• The virtual router redundancy (VRRP) protocol and IPv6 routing is not supported.
• Private VLANs (PVLANs) are not supported.
• When a Virtual Machine (VM) moves from one VLT domain to the another VLT domain, the VM host sends the gratuitous ARP
(GARP) , which in-turn triggers a mac movement from the previous VLT domain to the newer VLT domain.
• After a station move, if the host sends a TTL1 packet destined to its gateway; for example, a previous VLT node, the packet can be
dropped.
• After a station move, if the host rst PINGs its gateway; for example, a previous VLT node it results in a 40 to 60% success rate
considering it takes a longer path.
• When you remove and add back a MAC address, L3 frames can be received out-of-order at the L3 cloud. This happens when proxy
gateway routing and sub-optimal routing intersperse with each other.
Enable VLT Proxy Gateway
To enable the VLT proxy gateway, the system mac addresses of C and D in the local VLT domain must be installed in C1 and D1 in the
remote VLT domain and vice versa. You can install the mac address in two methods - the proxy-gateway lldp method or the
proxy-gateway static conguration. Proxy-gateway LLDP is a dynamic method of installing the local mac addresses in the remote
VLT domain, which is achieved using a new organizational type, length, value (TLV) in LLDP packets.
LLDP Organizational TLV for Proxy Gateway
• You can congure the VLT proxy gateway in a VLT domain using the proxy-gateway LLDP command in proxy-gateway
Conguration mode. Specify the port-channel interface of the square VLT link on which LLDP packets are sent using the
peer-
domain-link port-channel command.
Conguring the proxy gateway lldp and the peer-domain-link port channel, LLDP sets TLV ags on the interfaces for
receiving and transmitting private TLV packets. After dening these organizational TLV settings, LLDP encodes the local system mac-
addresses as organizational TLVs for transmitting to the peer. If you specify the no proxy gateway LLDP interface command,
LLDP stops transmitting and receiving proxy gateway TLV packets on the specied interfaces. However, other TLVs are not aected.
From the interfaces on which you enabled the proxy gateway LLDP, LLDP decodes the TLV packets from the remote LLDP by using
the new organizational TLV.
The following requirements must be satised for LLDP proxy gateway to function correctly:
• Data centers must be directly connected.
• LLDP has a limited TLV size. As a result, information that is carried by the new TLV is limited to one or two MAC addresses.
• You must have all related systems properly congured and set up.
• LLDP denes an organizationally specic TLV (type 127) with a unique identier (0x0001E8) and a dened subtype (0x01) for sending
or receiving information.
• LLDP uses the existing infrastructure and adds a new TLV for sending and receiving on the congured ports.
• There are only a few MAC addresses for each unit transmitted. All currently active MAC addresses are carried on the newly dened
TLV.
• Dell Networking devices not congured with VLT proxy gateway process standard TLVs and ignore TLVs congured with VLT proxy
gateway.
The LLDP organizational TLV passes local destination MAC address information to peer VLT domain devices so they can act as a proxy
gateway. To enable proxy gateway LLDP, two congurations are required:
• You must congure the global proxy gateway LLDP to enable the proxy-gateway LLDP TLV.
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VLT Proxy Gateway