Multi-homed Server

[Samuel Shum]

Hello, I've a Windows Server 2003 with 2 network cards installed. I've
assigned 1 real IP for one card and 1 private IP for another. Once I've done
so, I find that the server cannot connect to the internet (which supposes to
go thru the network card with real IP). All I want is that all traffics,
except destinated as 192.168.X.X, should go thru the interface which owns
the real IP. I think I mis-configured something, any advices? Thanks in
advance.

Samuel

 

[Marina Roos]

Can you post the ipconfig/all from the server? Have you checked the
bindingorder (Network Connections, Advanced, advanced) and made sure the
internal nic is on top?

Marina

 

[Doug Sherman [MVP]]

The private interface should have no default gateway configured. The public
interface should have a default gateway identified by your ISP. The public
interface should also use your ISP's DNS server; or if you are providing DNS
on the private interface on the server, it should point to that and the
server should be configured to use the ISP's DNS as a forwarder.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

 

[Samuel Shum]

That's exactly what my settings are: the interface with real IP has
default gateway, primary and secondary DNS; whereas the interface with
private IP has only subnet mask. Both are configured "automatic metric". The
problem is that once the configuration is done, the server cannot connect to
the internet; nor none of the machines from the internet can access the
server (no firewall in this case). It seems that all traffic are routed to
the interface with private IP... even no default gateway is defined.

Do I miss anything? Thanks again.

samuel

 

[Marina Roos]

DNS should *only* point to your server-IP, on both internal and external
nic.
Check the bindingorder and make sure the internal nic is on top.

Marina

 

[Doug Sherman [MVP]]

What leads you to conclude that "all traffic are routed to the interface
with private IP"? Can the server ping its public IP? If not, TCP/IP is
misconfigured or corrupt. Can the server ping the default gateway? If ping
times out, you may have the wrong gateway address, or your public IP/subnet
mask may be wrong. If you can ping the default gateway, can you ping
216.239.37.99? If that works, try to ping google.com. If that doesn't
work, your DNS entries may be wrong.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

 

[Samuel Shum]

Thanks all, once I put the DNS entries on the private interface,
everything works now!

samuel

 

[Marina Roos]

Great. Thanks for reporting back.