Re: Networking two locales [was: OT Search terms]

["Robert Holmgren" holmgren@xxxxxxxx]

** Reply to message from Patricia M Godfrey  on Sun, 30 Nov
2003 15:16:47 -0500


> Can anyone more knowledgeable than I about networking suggest some search
> terms I should use on DejaNews to find leads for configuring a laptop to
> belong to more than one network? It surely must be possible: lots of
> people want their laptops to log onto the office network and then their
> own home network. But I find nothing about it in any of my books. And if
> one doesn't know the jargon, a search could take forever. Thanks.

Off the top of my head, I'd say there are three paths:

Profiles which change your machines settings for different localities. You can
have more than one user profile on your machine. Control Panel ==> System ==>
User Profiles. But Win98 -- I'm not sure.

Another way to do this is to use DHCP. If both servers (and clients) use DHCP,
all you really need to do is plug in, and you're "up". Some Win98 machines
cannot plug in "hot" -- they need to be plugged already (connected to the
network via Ethernet or whatever) when they're booted (unplug them for any
reason, and you have to reboot to regain connectivity). NT machines hot plug
readily. Assuming you're lugging your machine back and forth, that shouldn't
be an issue.

If your server uses static IPs: The thing to do is to determine what your
machine's IP (network address) is. Let's suppose your server uses the LAN
range 192.168.1.xxx where "xxx" is 1 to 255 (192.168.1.xxx is reserved for LANs
and is the most common address range used by LANs). Either 1 or 255 will
usually be the address of the server -- let's say it's 192.168.1.1. So all the
other machines on the LAN have fixed addresses in range 192.168.1.2 through
255. Suppose your address is 192.168.1.8. Your "gateway" will be 192.168.1.1,
i.e. the server -- NOT the gateway address of your ISP. Depending on the type
of router you're using, you'll either use a proxy DNS on your server, in which
case your DNS is 192.168.1.1 -- OR you'll just add two external DNS addresses
to your settings, one for the ISP serving the office, the other for your home
ISP. A simple server will have two network cards: one serving the LAN, one
serving the WAN (and assigned your WAN address e.g. 236.75.45.24). At home,
mimic the settings at the office: set your server as 192.168.1.1, and keep
your machine as 192.168.1.8 -- everything in other words is identical at both
venues. PING is your friend when you're fussing with this stuff. Put an icon
on your Desktop that shortcuts to a couple of different addresses, something
like:

C:\WINNT\system32\cmd.exe /C ping.exe -a 206.26.230.225 & ping.exe -a
206.26.226.15 & ping.exe ftp.boulder.ibm.com

This is a very good test. First ping is to my WAN gateway, the "first hop"
after my server (the first external machine my server routes through on the
Internet highway). This simply tests whether I'm "up" (whether I'm configured
right, my wires are connected, and I have basic connectivity). Moreover, the
gateway machine could be located in a shack on top of a mountain (mine is); it
could be fully functional, but the home office (where DNS is done) may be dead,
power out, down for maintenace, whatever.

Second ping is to my DNS -- is the Domain Name Server up? I.e. is my ISP
healthy, and (the "-a" parameter) can it translate 206.26.226.15 into
"dns.midcoast.com" -- in short, can it name serve? If you're using a browser,
and suddenly it stops functioning, the DNS may have died, but the Net may still
be up. It happens, often.

Third ping is to a non-numeric domain name. This tests whether DNS is actually
working. It also tests whether your ISP is connected to its T1 or whatever
connection it has to the wider world. Sometimes your ISP can be an island unto
itself, healthy but cut off -- a chance to get acquainted with your ISP's home
page!

If anything fails, you start issuing manual PINGs to figure out what's going
on. Windows has the worst PING executable on the planet. It doesn't even keep
track of packet (ICMP) sequence. Total crap. It defaults to 4 pings and
quits. So when you're trying to get basic "up" status, and something is goofed
up, turn on a perpetual ping ("-t" param):

PING -t 192.168.1.1 <== connect to your server
 or
PING -t {WAN_gateway_address} <== connect to WAN

I can be more specific if you provide more info, but that's the gist of it.
I've done all these things many times, and it works. Let's face it, networking
at the level of bare connectivity is a very simple affair. You need four
numbers: your address, the server's address, your gateway address, and your
DNS address.

-----------------------------
Robert Holmgren
holmgren@xxxxxxxx
-----------------------------