Sample Configuration - Network Load Balancing (NLB) Multicast mode over routed subnet - Cisco Switch Static ARP Configuration
NLB Multicast Mode – Static ARP Resolution
- Since NLB packets are unconventional, meaning the IP address is Unicast while the MAC address of it is Multicast, switches and routers drop NLB packets.
- NLB Multicast Packets get dropped by routers and switches, causing the ARP tables of switches to not get populated with cluster IP and MAC address.
- Manual ARP Resolution of NLB cluster address is required on physical switch and router interfaces
- Cluster IP and MAC static resolution is set on each switch port that connects to ESX/ESXi host
- Virtual Switch NIC Team Policy > Notify Switches is set to Yes.
- If CDP (Cisco Discovery Protocol) is Enabled on ESX/ESXi and the Cisco Switch - you can determine proper switch ports connecting to ESX/ESXi via the vSphere/Virtual Infrastructure Client.
To configure the switch:
- Telnet in to Cisco Switch Console and log in.
- Run this command to enter Configuration mode:
- STATIC ARP RESOLUTION Cisco Global command mode
arp [ip] [cluster multicast mac] ARPA
arp 192.168.1.100 03bf.c0a8.0164 ARPA
- STATIC MAC RESOLUTION Cisco Global command mode
mac-address-table static [cluster multicast mac] [vlan id] [interface]
mac-address-table static 03bf.c0a8.0164 vlan 1 interface GigabitEthernet1/1 GigabitEthernet1/2