SUMM: High available IP address

From: Unix Administrator <unixadmin_at_gmd.com.pe>
Date: Wed, 11 Feb 1998 17:35:55 -0500

Many thanks to:

Eric Mermelstein [emermels_at_doas.state.ga.us]
Lou_A_Mullikin_at_32-bellevue_at_CCGATE.HAC.COM
Tom_Marco_at_mail.tmmna.com

The cryptic answer:

         ________ main IP address (lets say *.*.*.100)
NIC 0 ________ alias IP address (lets say *.*.*.101) <--------


         ________ main IP address (lets say *.*.*.102)
NIC 1 ________ alias IP address ( *.*.*.101 ) <------------------

In this way, the clients access to the system thru the *.*.*.101 IP
address, and when the NIC 0 fails, they can reconnect to the same IP
Address now on NIC 1 transparently. BUT, as Eric points out: "Just
remember, you can't have the IP address bound (aliased) to both NIC's
at the same time. You need to activate it (on the second NIC) should
the primary interface fail. Also (FYI) you set up the initial alias in
the "/etc/inet.local" file".


=======================================
The original posting:

Hi,
We are going to install a TruCluster Available Server environment with
two AS4100s. The scenario looks simple:

There are 8 disks on the shared bus which we want to make highly
available.
Both computers, A & B have two network interfaces, and the four
interfaces are connected to one single LAN.

We want the secondary NI to acquire the address of the primary
interface, in the event that the primary NI on computer A fails. We know
this as "floating address" on NT cluster environments. Any hints,
welcome

Thanks in advance,
==========================================

Received on Wed Feb 11 1998 - 23:33:56 NZDT