Dual Nics on different networks?

I currently have a gigabit backbone and run an all-managed
switch envioronment. i am well aware of the how switches
work and that they are unicast traffic. however my
concern was the utilization of the 1 nic in the server
being backed up. our data servers are highly utilized and
i don't wish to create a bottleneck by flooding that card
with all the backup traffic and the normal traffic that
traverses it, that was my logic behind setting up a
seperate nic.



>-----Original Message-----
>"Matthew" <(E-Mail Removed)> wrote in
message
>news:975201c49733$63b02130$(E-Mail Removed)...
>> Ok, if you are not supposed to use multihomed domain
>> controllers then how would your backup server be able to
>> login to the domain to backup all the servers it needs
>> to. each server the backup server is contacting has a
>> secondary gbit nic to communicate with that server on
that
>> private network. can you explain this? am i missing
>> something here?
>
>Multi-homing any machines other than Firewall or Proxy
machines is a
>"kludge" to begin with, that's why the problems that
exist with doing so
>actually exist. The proper way to have two subnets is to
put a router
>between the subnets and leave one NIC in all the
machines. High speed
>"backbones" are also supposed to be done with Routers
that are designed to
>run at those speeds. The physical topology of a network
should be
>independent of the computers that run on it and the
computers should not,
>themselves, make up the topology.
>
>I think a lot of people try to solve or avoid problems
that don't exist to
>begin with. I run our backup right across the normal
regular LAN and don't
>use an "backup network". It is a fully switched and
segmented LAN and the
>effect of the backup traffic doesn't even get noticed.
>
>Also the backup traffic is "directed" it is
not "broadcasted". So just using
>a Switch instead of a hub will already keep the
traffic "segmented" from the
>rest of the LAN even if it is all one segment.
>
>--
>
>Phillip Windell [MCP, MVP, CCNA]
>www.wandtv.com
>
>
>.
>

"Matthew" <(E-Mail Removed)> wrote in message
news:09be01c4973d$602a4a40$(E-Mail Removed)...
> concern was the utilization of the 1 nic in the server
> being backed up. our data servers are highly utilized and
> i don't wish to create a bottleneck by flooding that card
> with all the backup traffic and the normal traffic that
> traverses it, that was my logic behind setting up a
> seperate nic.

I understand.

The root of the problem is which way the machines resolve, which in turn
effects what route in the Routing Table they follow. When the multihomed
machines are "resolved" they will only resolve to one IP# or the other, not
both. If they resolve to the "backup segment" IP# then it will throw your
LAN functionality out of wack, but on the other hand if it always resolves
to the normal LAN IP# (which is should) then the "backup segment" won't even
get used. You have to find a way to overcome that. If there is a way to run
the backups by using only IP#s to identify the machines then that would
force the proper segment to get used.

I have thought the following method may work but have never tested it. You
could create "fake" machinenames for the machines and add them as static
entries in your WINS Server that are associated with the "backup segment"
IP#s, then by using these "fake" names the resolution would resolve to the
"backup segment" IP#s and would follow that segment for the traffic. You
may be able to do something similar with "fake" names in your DNS records
and accomplish the same tactic via DNS instead of WINS. Perhaps Hosts or
LMHost files could be used that way too.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com