adding another network card

  • Thread starter Thread starter Martin
  • Start date Start date
M

Martin

Hello folks

If I want to add a 2nd network card (same subnet , with fixed i.p.) for
load balancing , is it just a matter of assigning a new ip address to the
new card.?
Any help or pointers to useful links appreciated.
Thanks in advance
Martin
 
No. Load Balancing is joining two whole machines in a "Server cluster" (aka
MS Network Load Balanacing). What you are asking about is called "NIC
Teaming" which requires special ($$$) Nics that come with their own
proprietary software for performing this. This is not a Windows "thing". I
believe HP makes some Nics like this but I don't know the exact model.

Check out this artcle with respect to your original question.

175767 - Expected Behavior of Multiple Adapters on Same Network
http://support.microsoft.com/default.aspx?scid=kb;EN-US;175767

(In the case of Domain Controllers)
272294 - Active Directory Communication Fails on Multihomed Domain
Controllers
http://support.microsoft.com/default.aspx?scid=kb;en-us;272294
 
You cannot just add another card to a system and expect it to
participate in any fail-over operations. You cannot even give the second
NIC an IP address within the same IP network/subnetwork as the first
one. (Rule of the thumb, different physical interfaces of a network host
require IP addresses in sperate logical IP networks).

For implementing redundant NICs and links for proper failover, you will
need some kind of third party solution (both hardware and software) to
this, dell, intel, 3com all provide these solutions which are quite
expensive to implement.

A cheaper alternative however is to implement a workaround to this by
writing a batch file/script scheduled to run every so often to ping the
machine's gateway (or another host if one doesn't exist), if no replies
are recieved you could then disable the primary NIC, release its IP
address and activate the secondary "standby" NIC and give it the Primary
NICs IP address.

Here is a rough sketch of the command file.

:: BEGIN NICFailover.cmd

:: Ping the Gateway
ping 172.28.216.221 -w 5 -n 10

:: If no replies are recieved , set the IP address of "Local Area
Connection" (the primary Interface) to an address in a non-existant IP
Network.

if NOT %errorlevel% EQU 0 (
netsh interface IP set address name="Local Area Connection" static
10.28.216.209 255.255.255.240 10.28.216.222 50
)

:: END NICFailover.cmd

This script is incomplete, but i hope i have shown you enough for you to
be able to go ahead and make changes to wuit your needs.
 
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