Need help with XP network bridge concepts/implementation

J

jtpr

I have a machine with 2 NIC's in it nica and nicb. nica is dhcp on the
192.168.1.x subnet. nicb is dhcp on the 10.10.1.x subnet. I select
both of them an implement a network bridge. Will systems on one subnet
now be able to see systems on the other? Will sharing between subnets
work? What happens with DHCP?. Or, do both of the segments need to
be on the same IP subnets? If so, then what is the point? If my goal
is to have these two subnets share, but retain the different numbering,
what would be the best/easiest way to accomplish this? There are not
really many machines here, it is a small implementation.

-jtpr
 
S

Steve Winograd [MVP]

I have a machine with 2 NIC's in it nica and nicb. nica is dhcp on the
192.168.1.x subnet. nicb is dhcp on the 10.10.1.x subnet. I select
both of them an implement a network bridge. Will systems on one subnet
now be able to see systems on the other? Will sharing between subnets
work? What happens with DHCP?. Or, do both of the segments need to
be on the same IP subnets? If so, then what is the point?

The network bridge can't enable access between computers on different
subnets. Its purpose is to combine two physical networks (such as
wired and wireless) into one logical network, with one subnet. I've
written a web page with details:

XP ICS - Network Bridge
http://www.practicallynetworked.com/sharing/xp_ics/networkbridge.htm
If my goal
is to have these two subnets share, but retain the different numbering,
what would be the best/easiest way to accomplish this? There are not
really many machines here, it is a small implementation.

Doing what you want in a Windows XP workgroup network is possible, but
complicated, requiring several steps:

1. Enable TCP/IP forwarding on the 2-NIC computer, as described in
this Microsoft Knowledge Base article:

How to Enable TCP/IP Forwarding in Windows XP
http://support.microsoft.com/Default.aspx?scid=kb;en-us;315236

2. Assign static IP addresses to both NICs on that computer.

3. Create a persistent route on each of the other computers,
specifying the 2-NIC computer as the gateway to the other subnet. For
example, if the 2-NIC computer has IP addresses 192.168.1.1 and
10.10.1.1, use these commands:

192.168.1.x computer:

route -p add 10.10.1.0 mask 255.255.255.0 192.168.1.1

10.10.1.x computer:

route -p add 192.168.1.0 mask 255.255.255.0 10.10.1.1

4. Assign static IP addresses to all of the computers on both subnets.

5. Create an LMHOSTS on each computer that gives the name-to-IP
mapping for each of the computers on the other subnet.

You won't be able to see the other subnet in My Network Places. To
access a computer on the other subnet, type the other computer's name
in the Start > Run box in this format:

\\computer
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com
 
J

Jim

jtpr said:
I have a machine with 2 NIC's in it nica and nicb. nica is dhcp on the
192.168.1.x subnet. nicb is dhcp on the 10.10.1.x subnet. I select
both of them an implement a network bridge. Will systems on one subnet
now be able to see systems on the other? Will sharing between subnets
work? What happens with DHCP?. Or, do both of the segments need to
be on the same IP subnets? If so, then what is the point? If my goal
is to have these two subnets share, but retain the different numbering,
what would be the best/easiest way to accomplish this? There are not
really many machines here, it is a small implementation.

-jtpr
Since 192.168.x.x addresses and 10.x.x.x addresses are not routable, your
scheme is doomed. That is of course in addition to a bridge not being a
router.
Jim
 
S

Steve Winograd [MVP]

"Jim" said:
Since 192.168.x.x addresses and 10.x.x.x addresses are not routable, your
scheme is doomed. That is of course in addition to a bridge not being a
router.
Jim

You're right, Jim, that those addresses aren't routable over the
public Internet.

However, they are routable on a private network, which I assume is
what "jtpr" is asking about. Enabling IP forwarding on the 2-NIC
computer will enable it to route traffic between the two subnets.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com
 
J

jtpr

Steve said:
You're right, Jim, that those addresses aren't routable over the
public Internet.

However, they are routable on a private network, which I assume is
what "jtpr" is asking about. Enabling IP forwarding on the 2-NIC
computer will enable it to route traffic between the two subnets.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com

Steve,

Thank you for all the info, it is much appreciated. I'll fool around
with IP forwarding and see what that buys me...

-Jim (jtpr)
 
S

Steve Winograd [MVP]

Steve,

Thank you for all the info, it is much appreciated. I'll fool around
with IP forwarding and see what that buys me...

-Jim (jtpr)

You're welcome, Jim. There's a sample of an LMHOSTS file in
C:\Windows\System32\Drivers\Etc\Lmhosts.sam . You can edit that file
with a text editor. Then, save it as just "Lmhosts", with no ".xxx"
file type at the end of the name.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com
 

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