do they still make/sell network bridges? does anybody use them?

[FoBoT]

i have a situation at work in which i think we should bridge two subnets

we had talked about using a router or NAT device, but i think all we really need is a bridge

do they still make dedicated bridge devices? or should we just stick two network cards into an old junk PC and and use that or stick two network cards into our Windows 2003 Server and let it be the bridge ?

comments are welcome, thanks

this webpage basically replicates the situation i am talking about and why i am thinking bridge (except the USB part, ours is two ethernet subnets)

 

[NetWareHead]

I would just use a switch and plug both networks in. Switches are basically multiport bridges where a bridge is usually 2 port. You will want the IP address assignments to be on the same network on both sides whether you use a PC/server with 2 nics or a switch. If you want to join the 2 networks, but keep the IP addresses different (like join 10.1.1.x to 10.100.100.x), you need a router. Not a NAT device or home gateway but a real router like cisco.

 

[piasabird]

Can also solve this by using DNS Lookup. We have 2 devices for ATM Relay and we bridge them by using DNS lookup. If there is a certain prefix then it is routed to DNS and DNS server sends it to the other ATM if applicable. We have Students and staff and we have them separate for the most part. Instructors still have to reach the Mainframe from the student side.

 

[cleverhandle]

Originally posted by: FoBoT
i have a situation at work in which i think we should bridge two subnets... ours is two ethernet subnets

Then you intend to readdress the machines so that you have one subnet? Because that's what a bridge does - it merges two physical networks into one subnet. If you need to keep the networks on separate subnets for some reason, then you need a router.

But it doesn't really make sense to use a bridge with two ethernet segments - you need to readdress, and then you can just use a switch, as suggested (though I think that saying switch=bridge is a little glib). Usually you would use a bridge only when you have two networks with different media.

edit: typo

 

[FoBoT]

thanks

i think i got something mixed up

if i look up ethernet bridge, it says it is a layer two device, essentially as netwarehead says, at that layer connecting two lans with a switch does that

i saw a diagram that showed a "bridge" connecting two subnets with different ip ranges and pc's in both subnets seeing each other. a layer two device couldn't do that

so i am going to just setup my test network and try some stuff this weekend and see what works and what doesn't work

cleverhandle has the exact phase from the ethernet bridge/layer two definition with "use a bridge only when you have two networks with different media" and of course that matches to the link i posted above with the USB stuff

 

[cleverhandle]

Originally posted by: FoBoT
i saw a diagram that showed a "bridge" connecting two subnets with different ip ranges and pc's in both subnets seeing each other. a layer two device couldn't do that

The layout of the page is misleading. The top diagram, where there are two IP subnets, is using a router. Then the page substitutes a bridge for the router in the second diagram, but doesn't show the IP info in that diagram. That implies the two segments are two subnets, which isn't true. If you scroll down to the third diagram, it shows the IP info - which clearly has both segments belonging to the same subnet.

 

[ScottMac]

Bridges are also used for media conversion (copper to fiber). The IP addresses on both segments should be the same; if they're not, you'd still need a router for one segment to see the other segments hosts.

There are some "special" bridges that will convert Token-Ring to Ethernet, probably not applicable here.

As suggested, you could put two NICs in the server(s) if one segment's hosts don't need to communicate with the other segment's hosts (host to server only).

ATM 1493 bridges are slightly different animals. DNS lookup is not routing the different segments.

A small Cisco or Nortel router with two or more Ethernet ports will do what it appears you want to do.

FWIW

Scott

 

[mobly99]

You never really say exactly what problems you are trying to solve, but I am inferring from the content on the site you link to that you want Network Neighborhood browsing to work over two IP networks that are sperated by a router.

If that is the case, and as you say you have a 2003 server, why don't you just set it up as a WINS server and configure the clients to use it as their WINS server?


-Dave