Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.100.0 - Page 937

• 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 first 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. Enabling the 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 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 type, length, value (TLV) in LLDP packets. You can configure the VLT proxy gateway in a VLT domain using the proxy-gateway LLDP command in proxy-gateway Configuration mode. Specify the port-channel interface of the square VLT link on which LLDP packets are sent using thepeer-domain-link portchannel 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 macaddresses 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 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 satisfied 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 configured and set up. LLDP Organizational TLV for Proxy Gateway • LLDP defines an organizationally specific TLV (type 127) with a unique identifier (0x0001E8) and a defined subtype (0x01) for sending or receiving information. • LLDP uses the existing infrastructure and adds a new TLV for sending and receiving on the configured ports. • There are only a few MAC addresses for each unit transmitted. All currently active MAC addresses are carried on the newly defined TLV. • Dell Networking devices not configured with VLT proxy gateway process standard TLVs and ignore TLVs configured 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 configurations are required: • You must configure the global proxy gateway LLDP to enable the proxy-gateway LLDP TLV. • You must configure the interface proxy gateway LLDP to enable or disable a proxy-gateway LLDP TLV on specific interfaces. VLT Proxy Gateway 937