Enable And Disable Vlan Flooding; Configuring A Switch For Nlb - Dell S4820T Configuration Manual

Enable and Disable VLAN Flooding

• The older ARP entries are overwritten whenever newer NLB entries are learned.
• All ARP entries, learned after you enable VLAN flooding, are deleted when you disable VLAN flooding,
and RP2 triggers an ARP resolution. Disable VLAN flooding with the no ip vlan-flooding
command.
• When you add a port to the VLAN, the port automatically receives traffic if you enabled VLAN
flooding. Old ARP entries are not deleted or updated.
• When you delete a member port, its ARP entries are also deleted from the content addressable
memory (CAM).
• Port channels in the VLAN also receive traffic.
• There is no impact on the configuration from saving the configuration.
• If you enable VLAN flooding, it displays in the show running-config command output that displays
the ip vlan-flooding CLI configuration. This is the only output where you see the VLAN flooding
status (enabled or disabled).

Configuring a Switch for NLB

To enable a switch for Unicast NLB mode, perform the following steps:
Enter the ip vlan-flooding command to specify that all Layer 3 unicast routed data traffic going
through a VLAN member port floods across all the member ports of that VLAN.
CONFIGURATION mode
ip vlan-flooding
There might be some ARP table entries that are resolved through ARP packets, which had the
Ethernet MAC SA different from the MAC information inside the ARP packet. This unicast data traffic
flooding occurs only for those packets that use these ARP entries.
To enable a switch for Multicast NLB mode, perform the following steps:
1. Add a static ARP entry by entering the arp ip-address multicast-mac-address command in
Global configuration mode to associate an IP address with a multicast MAC address in the switch.
INTERFACE mode
arp ip-address multicast-mac-address interface
This setting causes the multicast MAC address to be mapped to the cluster IP address for the NLB
mode of operation of the switch.
2. Associate specific MAC or hardware addresses to VLANs.
CONFIGURATION mode
616
Microsoft Network Load Balancing