Linux equivalent of Windows NLB

Solution 1:

Here are a few that people find quite good in the Linux community (minus LVS at your request). I personally have only used HAProxy so your mileage may vary.

HAProxy
Balance

Only supports load balancing for http/https requests:

Pound
PLB - Pure Load Balancer

Solution 2:

see: http://lnlb.sourceforge.net/

Seems to be exactly what you are asking for.

That page summarizes it as: a common IP shared between all nodes (on a virtual interface). All you have to do is to bind on the virtual interface, the driver will do the rest.

It sounds very much like Windows NLB.

Solution 3:

If you want a loadbalancing like NLB you should have a look at clusterip in iptables. -> http://security.maruhn.com/iptables-tutorial/x8906.html

It does exactly the same, only the failover part is missing, but maybe there exists some tools for this.

Solution 4:

• If you are interested in BSD solutions - see CARP, linux as i just found out has port of it called UCARP
• About DNS-level load-balancing see CDN rfc3568, but beware - DNS-lb is kinda inert
• LVS is still pretty good so - check it out