Networking Problems - Host to Guest And Guest to Host...

I have a W2K Pro Desktop (Host) and have installed Win 2003 Server Std.
(Guest).

The problem is intermitent - The Host has a Asus [email protected] 802.11 NIC in
it and the Guest has by default installed: Intel 21140-Based PCI Fast
Ethernet Adapter (Generic). The wierd problem is that both Host and Guest
can access the internet with no problems, however they are only visible via
and ICMP Ping from time to time. It works and then stops. Over and over...
So they can both communicate to the outside world with no issues, but can
not talk to each other. My goal is to run IIS/Sharepoint on the Guest and
access it from the Host via IE, but it will not work on the private IPs that
are currently set up.

Host:
IP: 172.16.100.4
SN: 255.255.255.240
GW 172.16.100.1

Guest:
IP: 172.16.100.7
SN: 255.255.255.240
GW: 172.16.100.1

Again, both can access the internet perfectly with not real issues, but they
fail consistently to talk to each other - Please help!

Thank you,

RRBILLY

 

if u can see internet on other computers then this means there is no trouble
with hardware and ICS is enabled. there should b some settings needs
changing. now check if both computer are on same workgroup.
right click mycomputer -> click properties-> go to "computer Name" tab->
click change button and have a look they both are on same workgroup. after u
have done that then share some folder and see u can see on both computer... i
hope this helps.

 

All sorts of odd problems come up if you use wireless NICs. I can't ping
from host to guest (or vice versa) using my wireless NIC. Works fine using
the Ethernet NIC or the loopback adapter.

I would suggest setting up a loopback adapter on the host and using that
to communicate with the guest, rather than the wireless NIC.

 

Thank you for the reply...

To clarify - I can not ICMP ping host to guest or guest to host - well I can
now and then but not consistently. I change the IP and it works for awhile
and then stops again...

rrbilly

 

This is probably indicating that your wireless card's drivers are
working correctly and attempting to prevent MAC spoofing.

Try with a regular wired NIC and that will probably resolve your
issues. Or, you could use the MS Loopback adapter and ICS to bridge
to the wireless NIC.

Steve Jain, Microsoft MVP for Virtual PC for Windows
Website: http://www.essjae.com
*** All posts are provided AS-IS, no warranty, no QoS ***

 

You need to provide the details of the _current_ Host and
Guest configurations to make any meaningful response
possible.

Scott

 

Well the problem continues... I installed the loop back and still can not

Which steps have you taken?
- Install loopback adapter driver on *host*
- Assign the address 192.168.0.1 mask 255.255.255.0
- (Shut guest down)
- In VPC Console > Guest settings > Networking change Network Adapter to
the Loopback Adapter
(or say if it is not in the list; you may have to check the network
binding properties)
- (startup guest)
- Start guest, change TCP/IP properties to address 192.168.0.2 mask
255.255.255.0 default gateway 192.168.0.1
- (You might have to reboot guest)
- Now, from the host, try to ping 192.168.0.2
- From the guest, try to ping 192.168.0.1

If you want internet connectivity from the guest, just enable Internet
Connection Sharing on the host's network adapter that has the internet
connection. You may have to check DNS server properties on the guest or set
it to "use DHCP".

 

If I use the loopback, or the hardwired NIC, and try to add it to the same
network (172.16.100.0/28) as the WiFi adapter every configuraiton comes back
with the same problem - they can talk to the gateway and the Internet, but
Guest to Host & Host to Guest can not communicate. No ICMP, or TCP
communications. However, every now and then it works for a few minutes and
then dies again.

From an ARP perspective the devices (however configured - and rebooted until
the cows come home) all end up not in the ARP table. Again the goal is to
get Guest to Host & Host to Guest to see each other and share resources while
both have the ability to use the Internet...

So:
- Loopback did not work: Config - 172.16.100.11 /28
- Direct to WiFi did not work: Config - 172.16.100.11 /28
- OnBoard hardwired NIC did not work: - 172.16.100.11 /28

All seem to have the same problem.

Help?

RRbilly

 

You cant use the same network (172.16.100.0/28) on two adapters on the same
time on the same host. Make sure that the network numbers of the physical
(ie wireless) and loopback adapter do *not* overlap.

I recommend you using 192.168.0.0/24 addresses (see my post below) on the
"virtual" network (loopback adapter + guests) because then you can easily
turn on Internet Connection Sharing to get the guests connect to other
computers (with some limitations) & the Internet.

 

Ok - Let's run through it...

Starting with the basics:

Host (WiFi):
IP: 172.16.100.4
SN: 255.255.255.240
GW 172.16.100.1

No problems with network or access.


Guest:
IP: 172.16.100.7
SN: 255.255.255.240
GW: 172.16.100.1

Can connect to Internet through whatever virtual config I use - however can
not connect directly to Host. After the Guest has booted and uses either
WiFi (virtual), Hardwired (virtual), or Loopback; with the following
configuration:

Virtual Device:
IP: 172.16.100.11
SN: 255.255.255.240
GW: 172.16.100.1

Does this help?


RRBILLY...

 

See pml's reply to your other posting.

Scott

 

Comments inline->

Thank you for the advice so far, but can I ask why not? If two seprate
physical, or logical, devices have IPs on the same network, how is that an
issue? Two IPs - Two MACs - what am I missing?

 

In message <e9p$> "pml"

You can actually do this easily if they're physical adapters connected
to the same physical network.

However, putting one physical adapter and one loopback adapter in the
same subnet would be bad mojo.

 

Well, your approach *can* work, *if* you define ARP mapping manually and/or
route individual IP addresses though a specific network adapter (by using
the IF parameter in the route add command).

The reason why its not (generally) possible is that when you set up the IP
address and netmark for a network adapter, there will be an implicit route
created for that network through that network adapter, and if there is two
routes with the same metric, I guess the routing is kind of undefined and
the OS may choose the first network adapter that is up, and the OS will make
ARP broadcast on only that network adapter.

You can see the routing table by using the command
ROUTE PRINT
from the command line (cmd.exe in NT based OS:es; command.com in DOS based
OS:es).

 

Well I do want to thank you for the advice... I ended up rebuilding the
v-host onto the 192/24 network, as you suggested and it is up and running.
Not enough time to do more now except for make this internet connection stuff
work properly...

Anyways thanks again... I think that if I do it over again I will ditch the
ICS stuff and just add the routes...

Rrbilly...