Administrator Guide
1. The above figure (Topology 2) 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 undergoes sub-optimal routing with the VLT Proxy
Gateway LLDP method. For VLT Proxy Gateway to work in this scenario you must configure 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 configuration and not required in the static configuration. Sample Configuration
Dell(conf-vlt-domain)#proxy-gateway lldp
Dell(conf-vlt-domain-pxy-gw-lldp)#vlt-peer-mac transmit
2. ICL shut – Assume ICL between C1 and D1 is shut and if D1 is 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 behaviour is applicable only in the LLDP
configuration; in the static configuration, the packet is forwarded.
3. Any L3 packet, when it gets an L3 hit and is routed because of this feature, has a TTL decrement as expected.
4. You can disable the VLT Proxy Gateway for a particular VLAN using an "Exclude-VLAN" configuration. The configuration has to be
done in both the VLT domains [C and D in VLT domain 1 and C1 and D1 in VLT domain 2].
Static Proxy Configuration Method
Dell(conf-vlt-domain)#proxy-gateway static
Dell(conf-vlt-domain-pxy-gw-static)#remote-mac-address 01:23:45:67:89:ab exclude-vlan 10
Dynamic Proxy Configuration Method
Dell(conf-vlt-domain)#proxy-gateway lldp
Dell(conf-vlt-domain-pxy-gw-lldp peer-domain-link port-channel 1 exclude-vlan 10
5. Packet duplication may happen with “Exclude-VLAN” configuration – Assume exclude-vlan (say VLAN 10) is configured 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. If C’s MAC address is learned at C1, only (no
then) the packet is not have flooded (to D1) and only switched to C and thus packet duplication may be avoided.
6. With the existing hardware capabilities, you can only disable VLT Proxy Gateway only for 500 VLANs, using exclude-VLAN
configuration.
Configuring a Static VLT Proxy Gateway
You can configure a proxy gateway in VLT domains. A proxy gateway allows you to locally route the packets that are destined to an L3
endpoint of the other VLT domain.
To configure the static proxy gateway, perform the following:
1. Enable VLT on a switch, then configure a VLT domain and enter VLT-Domain Configuration mode.
CONFIGURATION mode
Dell(conf)#vlt domain domain-id
2. Configure the static proxy gateway.
VLT DOMAIN mode
Dell(conf-vlt-domain)#proxy-gateway static
3. You can configure the remote MAC address of a VLT peer for a static proxy gateway and exclude a VLAN or a range of VLANs from
proxy routing. This parameter is for a static proxy gateway configuration.
VLT DOMAIN PROXY GW STATIC mode
Dell(conf-vlt-domain-proxy-gw-static)#remote-mac-address mac-address exclude-vlan vlan-range
4. Display the VLT proxy gateway configuration.
EXEC mode
Dell#show vlt-proxy-gateway
Configuring an LLDP VLT Proxy Gateway
You can configure a proxy gateway in a VLT domain to locally route packets destined to a L3 endpoint in another VLT domain.
To configure an LLDP proxy gateway:
1. Enable VLT on a switch, then configure a VLT domain and enter VLT-Domain Configuration mode.
CONFIGURATION mode
VLT Proxy Gateway
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