Beginners question KEMP LB HA


In the documents I found that multiple HA connections should be used

on page 7 of  "Feature_Description-High_Availability_HA" document it is written that:
Three IP addresses are required for each subnet in which the LoadMaster is configured

In an two arm setup does that mean that I have to use HA (3 IP's) in each of the subnets
so that the CARP can run on net as well as on farm side ?

can I in addition also use for example eth2 (without IP's) in direct connection and enable -use this interface fore HA_checks?

so that finally the HA pairs could sync via direct-cable (eth2), farm-side (eth1), and net-side (eth0)

1 comment

Tony Vaughan


I will try to break this down to two sides,

1. routing

for routing you would need three IP address for each subnet that the LoadMaster is connected to,

Eth 0
IP address 1 HA unit 1
IP address 2 HA unit 2 
IP address 3 HA shared IP address

if other interfaces are used for traffic then these would also need three IP addresses

2. health checks

A direct cable can be used between two units, in the case it should be on eth1, as eth1 was designed for this scenario and there should be no IP addresses assigned to that interface

for HA to sync data this needs to be assigned to an interface with IP addresses on it,


I can have one of my colleagues in support contact you, just to make sure nothing is overlooked