Displaying And Maintaining Arp - HP 6125G Configuration Manual

NLB supports load sharing and redundancy among servers within a cluster. To implement fast failover,
NLB requires that the switch forwards network traffic to all servers or specified servers in the cluster, and
each server filters out unexpected traffic. In a medium or small data center that uses the Windows Server
operating system, the proper cooperation of the switch and NLB is very important. For more information
about NLB, see the related documents of Windows Sever.
Microsoft NLB provides the following packet sending modes to make the switch forward network traffic
to all servers or specified servers:
Unicast mode—NLB assigns each cluster member a common MAC address, which is the cluster
•
MAC address, and changes the source MAC address of each sent packet. Thus, the switch cannot
add the cluster MAC address to its MAC table. In addition, because the cluster MAC address is
unknown to the switch, packets destined to it are forwarded on all the ports of the switch.
• Multicast mode—NLB uses a multicast MAC address that is a virtual MAC address for network
communication, for example 0300-5e1 1- 1 1 1 1.
Internet Group Management Protocol (IGMP) multicast mode—The switch sends packets only out of
•
the ports that connect to the cluster members rather than all ports.
NOTE:
Multicast ARP is applicable to only multicast-mode NLB.
To configure multicast ARP:
Step
1. Disable the ARP entry check
function.
2. Configure a static ARP entry.
3. Configure a static multicast
MAC address entry.

Displaying and maintaining ARP

CAUTION:
Clearing ARP entries from the ARP table may cause communication failures.
Task
Display ARP entries in the ARP
table
Display the ARP entry for a
specified IP address
Command
undo arp check enable
arp static ip-address mac-address
vlan-id interface-type interface-number
[ vpn-instance vpn-instance-name ]
mac-address multicast mac-address
interface interface-list vlan vlan-id
Command
display arp [ [ all | dynamic | static ] [ slot
slot-number ] | vlan vlan-id | interface
interface-type interface-number ] [ count |
verbose ] [ | { begin | exclude | include }
regular-expression ]
display arp ip-address [ slot slot-number ]
[ verbose ] [ | { begin | exclude | include }
regular-expression ]
6
Remarks
N/A
Optional.
See IP Multicast Command
Reference.
Remarks
Available in any view
Available in any view