Need help with NETBIOS across two linked LANs

Ok, long posting....

Sad as though it may seem, myself and my next door neighbour have linked our wired LANs. They're using my fileserver for storing their pictures (clean...) etc, and we're performing backups to each other's house etc.

My LAN is 192.168.1.0/24, and my router is 192.168.1.1.

Their LAN is 192.168.0.0/24, and their router is 192.168.0.1.

In order to allow traffic to flow between them, my router has a secondary IP address of 192.168.0.254, and on their router I've added a static route 192.168.1.x to 192.168.0.254.

Each house has the default gateway pointing to its own router.

We have no DNS servers, except the DNS proxy that each router provides.

IP-wise, everything works perfectly. I can ping their computers, they can ping my computers. BUT...we can only do this via IP address, and for convenience (e.g. mapping network drives) we'd like to do it via NETBIOS name. We can map network drives via IP address (e.g. \\192.168.1.40\Pictures)

If I type ping 192.168.0.109 to access a computer in the other house, I get replies. If I type ping -a 192.168.0.109 I get Pinging CHRIS-PC [192.168.0.109] with 32 bytes of data, so there's clearly an element of resolution happening. But if I type ping CHRIS-PC I get ping request could not find host CHRIS-PC.

Needless to say I can ping any computer on my LAN via NETBIOS name and get a reply. They can ping any computer on heir LAN via NETBIOS name and get a reply. But we can't ping by NETBIOS name across the network.

Both computers (one on each LAN) are running Win7 RC, and therefore both have NETBIOS over TCP/IP enabled by default.

The two routers in question are a Cisco 877 and a NetGear SRXN3205.

I'm pretty sure this is a NETBIOS issue, but I've no idea what...

Many thanks,



Jim

Sounds like a DNS problem to me. If you don't have DNS resolution - which you won't get without a DNS server or entries in the "hosts" file - you won't be able to ping, or connect, by name. Try putting entries in your hosts files on the various computers. (Of course, that will require static IP addresses, or dynamic ones that don't change, but that's not a problem.)

Many thanks for the reply.

I'm trying to avoid HOSTS entries if I can. But I'm not entirely sure it's DNS. After all, why can I ping any device on my local LAN by name, even without a DNS server? And when I have pinged a device by name, and I then type nbtstat -r I see the newly-pinged device listed.

e.g.

Text

1 23 45 67 89 1011 1213 1415 1617 1819 2021 2223 2425 2627 2829 3031 3233 3435 3637 38

C:\Users\Jim>nbtstat -r      NetBIOS Names Resolution and Registration Statistics     ----------------------------------------------------      Resolved By Broadcast     = 30    Resolved By Name Server   = 0      Registered By Broadcast   = 78     Registered By Name Server = 0      NetBIOS Names Resolved By Broadcast---------------------------------------------          C:\Users\Jim>ping JANICELAPTOPPinging JaniceLaptop [192.168.1.168] with 32 bytes of data:     C:\Users\Jim>nbtstat -r      NetBIOS Names Resolution and Registration Statistics     ----------------------------------------------------      Resolved By Broadcast     = 30    Resolved By Name Server   = 0      Registered By Broadcast   = 78     Registered By Name Server = 0      NetBIOS Names Resolved By Broadcast---------------------------------------------            JANICELAPTOP

Your local lan, and your neighbours, will have DNS servers running on the routers (unless you've done something to disable them). Hence you can ping by name on the local network. But, I assume, you can't ping your neighbour's computer(s) by name - because you can't see their DNS server ( and vice versa). They probably have different network names as well, so you'd need to be using fully qualified names.

As a matter of interest, what's wrong with HOSTS entries? Not a good solution on large dynamic networks, but often the easiest way when only a handful of computers are involved.

I believe that NETBIOS name resolution over separate networks requires some form of bridging rather than just routing. If not, just think of the problems - all those millions of computers with NETBIOS names - you can't allow resolution by broadcast across that many computers. (Name clashes would be the least of your problems.)

Ok, I'll go for the hosts route. It'll do the job.

Many thanks,



Jim

When your computer attempts to resolve by NetBIOS (or NetBEUI) the broadcast is not forwarded beyond your subnet by default - so if you're on the 192.168.0.0/24 network the broadcast will not be forwarded over the layer 3 boundary to the 192.168.1.0/24 network.

On the Cisco router, you could set up an IP helper to forward these broadcasts to the other subnet (you will also need to enable directed broadcast) but for this to work both ways you would need to configure two separate layer 3 interfaces (using VLANs and assigning them to the physical ports on your 877) rather than using secondary addressing as you are now.