Servers -Teaming NIC

NOTE: Teaming for NIC's, a hardware solution not to be confused with Microsoft's "Network Bridge"

NIC's (Network Interface Card). NIC's come in different forms, one port, dual port, quad port. You can take two similar NIC's and team them.

One card that is easy to take two of and team very easily is the 3Com 3c905 series.

Note: Teaming NIC's is not the same as Microsoft Windows Network Bridge feature in the network properties. Teaming takes in to consideration the physical characteristics of the NIC's being teamed and has manufacture specific software to do the teaming. You can change the MAC address of the Teamed NIC's where as using the Bridge method (dissimilar NIC's) you can not change the MAC nor will you have any type of redundancy.

Before we get to the teaming of the nic's there are a few things you should know about network cards and hub/switches.

Teaming NIC Information:

To get the fullest potential from your network you should set these parameters:

Flow Control -

Speed - 100 or 1000, your network will only be as fast as the slowest card regardless of the hub/switch brand.

IP Range -

IP - Always set your HUB/Switch IP range first! Normally people select the generic 192.168.1.0 subnet, this is cool, all the hackers like to know what your IP range is makes it easier for them. Pick an IP range anywhere but 192.168.1.0, Your network will be behind a router/firewall so the actual IP range is your choice, the harder you make it for the hackers/crackers/thieves the better it is for you!

Teaming NIC Instructions:

Now for the teaming -

Depending on your network cards you will either get a utility or will have to use Windows Network Bridging (Note: MS Bridging does not change the MAC of each individual NIC, it adds another MAC to the Bridge software, this adds overhead to the network parameters of you network).. If you buy a dual or quad NIC you should get a utility with the NIC. The one that I always use is from HP/Compaq.

When you start the utility you have a choice of the NIC's in the computer, select the NIC's you want to team, then team them.

You will want to team the NIC's by IP or MAC code, I use IP but that is a personal choice - some routers/switches have a "fall over on fail" that utilizes the MAC code vs. the IP check with the Network Engineer or the router/switch documentation for this option.  Normally you will want to use Load Balancing, you could use Fault tolerant. For speed use Load Balancing and Balance with IP Address.

Unless you have a high end switch such as the Cisco 4800 or higher series don't use Switch-assisted Load balancing.

Once you have the team setup a new ICON will appear in the Network Properties box, this will be the IP of the server, set your network properties. Once you have the properties setup (some utilities require a restart) and the icon in the tray you should see the dual nic at 200 or 2000 (if you have a gigabit NIC) if you only see 100 MBPS for the icon check your settings. Insure both cards flow control is set to 100/Full or 1000/Full.

Servers - Teaming NIC this page was extracted from Build a Server Guide.

Teaming NIC's Notes -

Teaming will only be available to your local network, it will not make any difference to a connection to your ISP.

Your HUB/Switch at a minimum MUST support 100/Full or 1000/Full flow control.

When you connect your Cat5/Cat6 cables to the HUB Switch use ports side by side.

If you are using Fault tolerant you need to have two HUB/Switches you would put one cable in one HUB/Switch and one in the other HUB/Switch, this allows for fall over if a NIC, port, cable, or HUB/Switch fails.

Servers -Teaming for NIC's

A word of caution about failed dual Teamed NICs:

If your network is a secured network and you do not have access to the local administrator's id and password and / or do not have a local user id for administrators do not break the team on the Teamed NIC until you have a secondary connection to your domain.

To break a Team you have to use the software from the NIC manufacture, do not remove a malfunctioning NIC from a server with out first breaking the Team. To break a team you have to have Administrative rights and the NIC manufacture's software.

DO NOT UNDER ANY CIRCUMSTANCES REMOVE THE FAILED CARD BEFORE BREAKING THE TEAM!

Doing so will cause an interruption to your network or worse crash the network. (This comes from experience...)

In some extreme cases you will have to install the Operating System once again, especially if the server is in a Domain where there is NO local Administrator which is a "Best Practice" in some companies.

If your security is domain security and you do not have access to the administrators account or secondary administrator account when you break the teaming the system will restart, once you restart you will not be able to log on to the system to set the IP. If your dual nic fails then install a secondary nic card and configure it with a static IP before breaking the team or uninstalling the bad card.