One Server, 2 NIC's

qwertyiop

I came across an issue where my Windows Server 2008 R2 which has 2 NICS. This server is hosting a application database and I've noticed that my user can access the database just fine but it tends to be slow and freeze up while while accessing it. Ive noticed that its automatically sending all data through both the second NIC before the first thus causing latency when accessing the database.

Does windows have a builtin way to handle what data goes where or do you have any ideas that might work for me?

sratakhin

A few questions:

Which subnet are your users on?
Do you have two default gateways?
Does the DNS name of the server resolve on the first or second NIC?

qwertyiop

2 completely separate gateways and subnets. NIC 1 is on a /24 and NIC 2 is on a /29. DNS does indeed resolve to the correct server but it information flowing out from the server is being sent out through a random NIC before being resent and eventually received by my clients.

sratakhin

Can your clients actually reach the server by going through the /29 subnet?

qwertyiop

No, the /29 is for another purpose is is segregated for a reason.

it_consultant

qwertyiop wrote: »

I came across an issue where my Windows Server 2008 R2 which has 2 NICS. This server is hosting a application database and I've noticed that my user can access the database just fine but it tends to be slow and freeze up while while accessing it. Ive noticed that its automatically sending all data through both the second NIC before the first thus causing latency when accessing the database.

Does windows have a builtin way to handle what data goes where or do you have any ideas that might work for me?

This functionality is handled in Windows 2012 at the OS level:

NIC Teaming in Windows Server 2012 Brings Simple, Affordable Traffic Reliability and Load Balancing to your Cloud Workloads - Building Clouds Blog - Site Home - TechNet Blogs

In server 2008R2 this is handled by the manufacturer of the NIC card. For example, the intel PRO1000 server adapters can be teamed in coordination with the switch (via LACP) or independently of the switch of your switch does not support LACP.

Those options just bond your NICs together to give you 2Gb of throughput, it is not wise to the ways of your database can cannot parse out the traffic from your application. Usually you need a load balancer to do that. To the best of my knowledge ethernet does not support anything like 'least congested path' which we have in the SAN and iSCSI world.

*EDIT* Sorry, I saw your update, your two NICs are on different VLANs. None of what I said matters!

Zartanasaurus

Does traffic ever need to route THROUGH the special /29 network? If not, then just remove the default gateway on that NIC. You shouldn't have two default gateways on a server.

kriscamaro68

Have you tried this?

Type ncpa.cpl in run
In the network connections window hit the alt key and click on advanced in the dropdown then advanced settings.
Under adapters and bindings tab there is a section called connections. From there you can choose the order of the adapters you want network services to use first. Set the adapter that uses the subnet for the app as the first then the other as the second. It should still allow for access to the other network but use the /24 as the primary for all network traffic.

CodeBlox

I'd remove the default gateway on the NIC with the /29 subnet. That or add a custom route statement on the server to send all traffic to a specific NIC. Possibly even remove the default route on the /29 NIC.

undomiel

CodeBlox and Zartanasaurus have it right. Remove the default gateway from the nic that should not be routing traffic to the rest of the network. It would also be a good idea to double check things to make sure that the unroutable nic is not set to register in DNS

qwertyiop

Thanks for all your reply's but I think I figured it out. I ended up changing the default gateway metric order to give the NIC with the IP from /24 priority over the /29