Connection order with multiple NICs

[CiscoKid]

If you look at the 'Adapters and Bindings' tab of the 'Advanced Setting'
under the 'Network Connections" window, it says 'Connections are listed in
the order in which they are accessed by network services'. Exactly what
services are they talking about? Which services are going to default to
using the first adapter in the list? I know that Windows 2000 actually
mentions DNS specifically here. I've done some traceroute testing using
TRACERT and it appears to me that routing decisions are being made
correctly, at least as far as TRACERT shows. We are getting ready to deply
a new project where they want to use a second NIC to interconnect all the
hosts associated with the project and use the other NIC for connectivity to
the core network. I really don't see the use, given the traffic between
the projects' hosts are not going to be outrageous. Anyway, I wanted to
find out the Windows multihome gotchas beforehand.

Thanks in advance,

Mike

 

[Guest]

There are only a few 'gotchya's' that I can think of for this. My network
systems all have 4 port adaptec ethernet cards installed. Each system get's 3
network connections, so i have a little experience with this type of stuff.

The first problem is going to be NETBIOS. If your NIC's are configured to
use WINS or DNS. Make sure only one of the ports are configured to point to a
WINS/DNS server. IF a system tries to register both adapters to a WINS/DNS
server, it will use the same hosname for each registration (but different IP
address) and you will start to see errors that say "There is a duplicate
hostname on the network. Network operations may be temporarily disabled"

The second is the provied order for the cards. This order establishes witch
NIC to use first for network services. You should determine witch NIC is
going to be used more heavly and set that NIC higher in the provider order
list. This will allow your network and workstation to run faster when
accessing the network.

The only other thing I can say is make your configurations standard. If port
1 goes to the normal / public network and the second NIC goes to the private
(new) network, make this consistant through out your setup. If you do not,
you will be hating life, trust me.

HTH

Drum on .. .. . . .

 

[CiscoKid]

Thanks so much for your reply. This is the kind of stuff I need. Your
description in the last paragraph is right on the money....because that's
how they term it at work....the public network...being the core....and the
private network...being the network interconnecting hosts that make up the
particular application. One additional question though....which network
services are going to use the first adapter in the list? My thinking is
that when data is working down the layers...when it reaches the network
layer, things are going to go outbound based on the routing table. So I
would think that outbound traffic to the other application related servers,
since their IPs are going to be in the same network, are going out the
private NIC. Are there certain network services that are going to make the
decision to use the first adapter? This is the one piece that concerns me.
I would hate to find out that Oracle connections between an application
server and a database server interconnected through the private network are
actually talking through the public or core switch.

Thanks again,

Mike