Browser Routing Failure: single machine with 2 physical NICs and 3 logical NICs

  • Thread starter Thread starter naipaul
  • Start date Start date
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naipaul

I have narrowed down my WWW browsing problem to the fact
that I have multiple NICs configured on a single laptop
server. Once the logical NICs are disabled routing is
correct.

I use my laptop at home and work. I have a 100Mb Lan at
work and 100Mb/Wireless network with broadband router at
home. To access my corporate LAN at home I use a VPN
client. Currently the Wireless and Physical Lans are
mutually exclusive active and both use DHCP.

I use VMWare to run a secondary OS, which creates 2
virtual NICs. I have configured the VMWare OS to access
the external LAN by NAT'ing one of the virtual LANs to the
physical active LAN.

To minimize the size of the VMWare images, I share the
host disks to the VMWare image. Because all physical NICs
are configured to use DHCP with a new set of addresses
when the VPN is configured - I have added a loop-back
adpater with a fixed IP-Address --> this has no gateway
configured.

I have tried to configure the order of NICs via the
Advanced Networking.

Order Summary supposedly configured:-
1. Intel NIC 100Mb --> (dhcp) Work/Home
2. Intel NIC 11Mb - Wireless --> (dhcp) Home
--------------
3. VMWare Virtual NIC --> NAT address to external (dhcp)
4. VMWare Virtual NIC --> internal private Network (dhcp)
5. MS LoopBack Adpater --> fixed IP Address, no gateway
--------------
6. Dial-up Modem

Occassionally when I power up the laptop, I get a DHCP
address with DNS on either physical NICS but I am unable
to ping any WWW sites or to resolve any sites.

Temp Resolution:-
If I disable the Loopback and Virtual adapters I get
correct routing to the Web. Once a route has been
established, re-enabling the Virtual Adpaters do not
hinder the proper name resolution.

Questions:-
1. How to configure the adapters to prioritise the
physical NICs
2. Can the Loopback Adapter be configured with a gateway ?
 
naipaul said:
I have narrowed down my WWW browsing problem to the fact
that I have multiple NICs configured on a single laptop
server. Once the logical NICs are disabled routing is
correct.
Click to expand...

That will not be the DIRECT cause but may be an influence in the
improper configuration.

"route print" and inspect you routing table under each OS.

Tracert to a location and determine the actual routing being used.

Compare the two and work from there.

Remember that you can MANUALLY OVERRIDE a DHCP assigned
DNS, router etc and still obtain the DHCP provided address (most people
don't know this.)

Your situation (multiple NICs, multiple nets, VPN, and multiple OS's with
VMware) is complex beyond the expectation of Windows and if it works
easily you got lucky.

You can use a "netsh.exe" script to reconfigure at each location or in each
OS if nothing else works.

NetSh(ell) syntax is very hard to learn but there is a trick: Output the
current
(working) configuration to a file and use the "exec" command to reload it
(or
edit the output and reload a different set of values.)
 
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