Making the most of dual nics
I have a new I7 Vista 64 machine with a Realtek RTL8168C(P)/8111C(P) dual gigabit Nic(s). It is functional, but while I have found posts for Server 2008 on how to configure virtual Nics they are not really applicable. I would like to configure them to take the best advantage of the two Nics. Right now when I look on the status details one Nic seems to do all the work (the one with the lower static address). Both are accessable, pingable and accessable. I have spent a lot of time looking including the vendors site. I guess there are so many options one doesn't know where to start.I have a simple network home office, I use remote desktop, and I have a private IP with a VPN gateway. Again, everything works fine. It would be great if some one could explain to me how to... bindboth Nics to one address, or suggest to use one to VPN in orconfigure 1 nic forinternet traffic and one forLan.Any suggestions would be helpful. The lan is a simple one segment 192.168.5.x. The Nics are set to static addresses 192.168.5.8 & 9 respectively. DHCP is disabled, autoconfig is on, IPv4 & 6 are enable IPv6 is set to automatic... by the way, pinging by computer name generates the ipv6 address and this is also the one that has no usage and is the nic configured with the higher number 192.168.5.9. Most of the usage was internet, with no significant communications with other Vista machines in the networ.Thank you in advance for any suggestions you might have.scott
June 5th, 2009 8:16am

Hi, Thank you for your post. Based on my research, I would like to provide you the following suggestions: 1. We may have no need to make the 2 NICs work simultaneously. I noticed that the NICs are both Gigabit-based, if your net work connection speed is not more that 1 Gigabit, you can just use one NIC. 2. As you have two NICs, each network adapter has routes; however, only one default route is actually used. Therefore, the connection activity may just occur in one NIC. Meanwhile, I would also share the following with you: Source IP address selection on a Multi-Homed Windows Computer http://blogs.technet.com/networking/archive/2009/04/24/source-ip-address-selection-on-a-multi-homed-windows-computer.aspx The IP routing table http://technet.microsoft.com/en-us/library/cc779122.aspx Hope this helps. Thanks.Nicholas Li - MSFT
Free Windows Admin Tool Kit Click here and download it now
June 8th, 2009 12:56pm

Nicholas,The links you gave me explain the behavior. Since I would presume most applications use IPADDR_ANY to determine which address/nic to use this explains why typical applications i.e. Internet Exploreralways use the same address, the default address. So, as you say there is effectively only one default rout. So I am agreeing that if you use "default" behavior it will only use one route/nic based on the routing table rules, which are slightly different in Vista and XP, but the result is the same, that is only one default can exists. Therefore there is no automatic load balancing when you have multiple NICs.So the only way to load balance is somewhat manually. What I have also found is that many applications can be overridden to use the other NIC if I actually specify that address. For example, if I specify the non-default NIC as the host for Remote Desktop I can observe it will use that NIC instead of the default. The same is true of SQL SERVER 2008 etc. So if I want to have other applications use the other NIC I have to specify the other address. I haven't tested it, but I presume you could use the hosts files on client machines to force them to use the other NIC. So while this isn't perfect you could at least use the other NIC for specific applictions.Thank youScottscott
June 15th, 2009 3:17pm

This topic is archived. No further replies will be accepted.

Other recent topics Other recent topics