Problem:
Experiencing trouble sending or receiving data because of server configuration
Background:
The strong host model was introduced in RFC 1122 for IPv4, but the concept also applies to IPv6.
If a computer with more than one network interface uses the strong host model, it will only transmit the data packets out of the NIC if the source IP matches the IP address of that NIC. This computer will only receive data packets if the destination IP matches the inbound NIC IP address.
If a computer uses the weak host model, it can send data packets out of any NIC even if the source IP doesn’t match the specific outbound NIC IP. This computer will receive data packets addressed to any IP address that is assigned to any NIC on the computer.
Most computer operating systems use the weak host model, except for Windows. Beginning in 2007, Microsoft tightened security and made the default the strong host model for both IPV4 and IPV6.
Out-of-Path (OOP) load balancing requires the server NIC to send and accept packets for the loopback adapter address. This address is the same as the FARM address on the load balance. OOP mode is helpful when large packets must be sent back to the client without using the load balancer.
Solution:
To enable the weak host model on Windows 2008 and later, open the command line with administrator privilege. Enter:
If your computer runs in Out-of-Path load balancing mode, the administrator needs to enable “weakhostreceive” on the server NIC and loopback adapter, as well as “weakhostsend” on the loopback adapter.