Solved

NLB - unicast Vs multicast

Posted on 2013-01-30
3
717 Views
Last Modified: 2013-01-31
Hi - can someone please describe in lay-man's terms the difference between these two modes in network load balancing, it is so confusing what I've found online...

Thanks!
0
Comment
Question by:fredostare
  • 2
3 Comments
 
LVL 57

Expert Comment

by:giltjr
ID: 38837738
Do you know and understand the difference between unicast and multicast as it relates to IP in general?
0
 

Author Comment

by:fredostare
ID: 38839164
HI giltjr, well, my limited understanding would be that unicast would be broadcasting to one specific host and multicast would be broadcasting to many... is that anywhere near?
0
 
LVL 57

Accepted Solution

by:
giltjr earned 500 total points
ID: 38839210
That is correct.  It's not really broadcasting, but it is sending traffic to more than one destination using a single MAC/IP address and a single frame/packet.

In NLB unicast you must have 2 NIC's.  One that will be used for the NLB traffic and one for the two servers to talk to each other.  This is because in unicast mode, both hosts will use the same IP address for NLB traffic.  

In NLB multicast mode you can get by with a single NIC, but it is not recommended generally.  This is because MS uses a multicast MAC address which can exist on multiple devices.  MS does break standards here because they use a multicast MAC address with a unicast IP address, which is not really valid to do.

Both modes have their advantages and disadvantages because of the way switches work.  In fact because different switches work different ways unicast may be better on some switches while multicast on others.

Read this and see if it helps:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006580
0

Featured Post

Netscaler Common Configuration How To guides

If you use NetScaler you will want to see these guides. The NetScaler How To Guides show administrators how to get NetScaler up and configured by providing instructions for common scenarios and some not so common ones.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

#Citrix #Citrix Netscaler #HTTP Compression #Load Balance
This is an article about my experiences with remote access to my clients (so that I may serve them) and eventually to my home office system via Radmin Remote Control. I have been using remote access for over 10 years and have been improving my metho…
Internet Business Fax to Email Made Easy - With  eFax Corporate (http://www.enterprise.efax.com), you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, f…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…

895 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now