Enabling The Vlt Proxy Gateway - Dell C9000 Series Networking Configuration Manual

5 The connection between DCs can only be a L3 VLT in eVLT format. For more information, refer to the
eVLT Configuration Example
6 Trace route across DCs may show extra hops.
7 You must maintain route symmetry across the VLT domains to ensure no traffic drops. When the routing
table across DCs is not symmetrical, there is a possibility of a routing miss by a DC that does not have the
route for the L3 traffic. Because routing protocols are enabled and both DCs come in the same subnet,
there is no route asymmetry dynamically. But if you configure the static route on one DC and not on the
other, there is asymmetry.
8 If the port-channel specified in theproxy-gateway command is not a VLT LAG, the configuration is
rejected by the CLI. The VLT LAG cannot be configured as a legacy LAG when it is part of a proxy-
gateway
9 You cannot change the LLDP port channel interface to a legacy LAG when you enable the proxy
gateway.
10 Dell recommends using thevlt-peer-mac transmit command only for square VLTs without diagonal
links.
11 VRRP and IPv6 routing is not supported.
12 Private VLANs (PVLANs) are not supported.
13 When a VM moves from one VLT domain to the another VLT domain, the VM host sends the gratuitous
GARP. The GARP triggers a mac movement from the previous VLT domain to the newer VLT domain.
14 After a station move, if a host sends a TTL1 packet destined to its gateway; for example, a previous VLT
node, the packet may be dropped.
15 After a station move, if a host first PINGs its gateway; for example, a previous VLT node it results a 40 to
60% success rate considering it takes a longer path.

Enabling the VLT Proxy Gateway

To enable the VLT Proxy Gateway feature, 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 configuration. 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 TLV in LLDP packets.
The VLT proxy gateway can be configured in a VLT domain context using the cli command proxy-gateway
LLDP. You enter the proxy-gateway Configuration mode when you enter this command. The port-channel
interface of the square VLT link on which LLDP packets are to be sent is specified by thepeer-domain-link
port-channel command.
Configuring the proxy gateway lldp and the peer-domain-link port channel, LLDP sets TLV flags on
the interfaces for receiving and transmitting private TLV packets. After defining 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 specified interfaces. However, other TLVs are not affected. From the
interfaces on which proxy gateway LLDP is enabled, LLDP decodes TLV packets from the remote LLDP by
using the new organizational TLV.
The following requirements must be satisfied for LLDP proxy gateway to function correctly:
• Because LLDP is a direct link protocol, data centers must be directly connected.
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