Users Guide

• The above gure shows a sample VLT Proxy gateway scenario. There are no diagonal links in the square VLT connection between
the C and D in VLT domain 1 and C1 and D1 in the VLT domain 2. This causes sub-optimal routing with the VLT Proxy Gateway
LLDP method. For VLT Proxy Gateway to work in this scenario you must congure the VLT-peer-mac transmit command
under VLT Domain Proxy Gateway LLDP mode, in both C and D (VLT domain 1) and C1 and D1 (VLT domain 2). This behavior is
applicable only in the LLDP conguration and not required in the static conguration.
Sample Conguration
Dell(conf-vlt-domain)#proxy-gateway lldp
Dell(conf-vlt-domain-pxy-gw-lldp)#vlt-peer-mac transmit
• Assume the inter-chassis link (ICL) between C1 and D1 is shut and if D1 is the secondary VLT, one half of the inter DC link goes
down. After VM motion, if a packet reaches D2 with the destination MAC address of D1, it may be dropped. This behavior is
applicable only in an LLDP conguration; in a static conguration, the packet is forwarded.
• Any L3 packet, when it gets an L3 hit and is routed, it has a time to live (TTL) decrement as expected.
• You can disable the VLT Proxy Gateway for a particular VLAN using an "Exclude-VLAN" conguration. The conguration has to
be done in both the VLT domains [C and D in VLT domain 1 and C1 and D1 in VLT domain 2].
Sample Conguration LLDP Method
Dell(conf-vlt-domain)#proxy-gateway ll
Dell(conf-vlt-domain-pxy-gw-lldp)#peer-domain-link port-channel 1 exclude-vlan 10
Sample Conguration Static Method
Dell(conf-vlt-domain)#proxy-gateway static
Dell(conf-vlt-domain-pxy-gw-static)#remote-mac-address <xx:xx:xx:xx:xx:xx> exclude-vlan
10
• Packet duplication may happen with “Exclude-VLAN” conguration – Assume you used the exclude-vlan option (called
VLAN 10) in C and D and in C1 and D1; If packets for VLAN 10 with C’s MAC address (C is in VLT domain 1) gets an L3 hit at C1 in
VLT domain 2, they are switched to both D1 (via ICL) and C via inter DC link. This may lead to packet duplication. Therefore, if C’s
MAC address is learned at C1, the packet does not ood to D1 and only switches to C and avoids packet duplication.
• With the existing hardware capabilities, you can only disable VLT Proxy Gateway only for 500 VLANs, using exclude-VLAN
conguration.
Conguring an LLDP VLT Proxy Gateway
You can congure a proxy gateway in a VLT domain to locally route packets destined to a L3 endpoint in another VLT domain.
Apply the following congurations in the Core L3 Routers C and D in the local VLT domain and C1 and D1 in the remote VLT domain:
1. Congure proxy-gateway lldp in VLT Domain Conguration mode.
2. Congure peer-domain-link port-channel <vlt portchannel ID> in VLT Domain Proxy Gateway LLDP mode.
The VLT port channel is the one that connects the remote VLT domain.
Sample Dynamic Proxy Conguration on C switch or C1 switch
Switch_C#conf
Switch_C(conf)#vlt domain 1
Switch_C(conf-vlt-domain1)#proxy-gateway lldp
Switch_C(conf-vlt-domain1-pxy-gw-lldp)#peer-domain-link port-channel 1....
924
VLT Proxy Gateway