N-central Help

KBA20020: Configuring A Server With Multiple NICs

Knowledge Base Article #: 20020
Applicable Versions: SolarWinds N-central 9.x
Date Created/Updated: December 3, 2014

Introduction

Windows servers with multiple NICs (Network Interface Controllers) and SolarWinds N-central Probes may experience communication issues due to a problem with how Windows manages data communication with the different NICs. This may impact SolarWinds N-central functions such as Patch Management when Probes are unable to communicate with Agents due to use of the incorrect NIC address.

Troubleshooting

Windows will perform NIC selection by examining the entire IP route table so that it can choose the best network adapter over which to send data packets. After a network adapter has been selected, the stack will follow the address selection process defined in RFC 3484 and use the selected IP address as the source IP address for outbound data packets.

To resolve this issue, define a routing entry for the specific NIC through which SolarWinds N-central data packets are to be transmitted.

For more information on this issue, refer to http://blogs.technet.com/b/networking/archive/2009/04/25/source-ip-address-selection-on-a-multi-homed-windows-computer.aspx.