Can NLB be used on IIS serves on a different subnets

Posted on 2009-02-19
Last Modified: 2012-06-21
Probably a stupid question but here goes. We have two IIS WEB servers on one subnet and we have setup NLB to allow us to load balance access to a specific URL and this seems to work on the local subnet fine. However we then discovered that we cannot access this from a different subnet. I am therefore assuming that we have not set this up correctly or NLB is intended for use on a single subnet. We use a piece of softare that relies on using a web service to authenticate the login. At present our users are spread over 10 sites and  autheticate to a single WEB server at one remote site (SITEA)which is  a sinle point of failure. We thought NLB would allow us to build in some redundancy of that one server. We then planned to setup another NLB Cluster at another geographical site (SITEB)and configure half our users to point to teh URL at SITEA and teh rest to SITEB therefore giving us site and server resiliance thus improving availabliltiy and splitting the load. Our other alternative is to use MCS to cluster IIS but i read this is not best practice as NLB is. Surely NLB cannot be for single subnet use?
Question by:KWRoss
    1 Comment

    Accepted Solution

    Just for info: We had Multicast selected so we went wiht teh recommendations to use Unicast wiht dual Network Cards. A quick test on one server wiht Unicast allowed us to ping the NLB Virtual IP address across the WAN. All we need to do now is break our Network Teaming and configure one NIC for base traffic and configure the other for NLB.

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    Find Ransomware Secrets With All-Source Analysis

    Ransomware has become a major concern for organizations; its prevalence has grown due to past successes achieved by threat actors. While each ransomware variant is different, we’ve seen some common tactics and trends used among the authors of the malware.

    Today I came across an interesting issue that had me pulling my hair out.  I was troubleshooting a new internal web site which uses integrated security instead of anonymous.  When browsing the site from my laptop, I was able to access it with no iss…
    First of all, clustering IIS is something you should rarely consider doing. In almost all cases, Microsoft Network Load Balancing (NLB) ( is a much better solution when you need to p…
    This video discusses moving either the default database or any database to a new volume.
    Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…

    759 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

    13 Experts available now in Live!

    Get 1:1 Help Now