Network Places and DHCP on home lan

[Harry Putnam]

I've always used static addresses inside my home lan until today. I'm
trying to use a netopia router designed for dsl/cable to lan. But
really using it inside the lan only as a wireless access point.

Summary: I need a list of ways normally used to trouble shoot network
when dhcp addresses are in use.

Details:
I've tried many setups but the only one I could get to work so far
that allows me to get what I wanted (a wireless segment inside home
lan)

Looks like : INTERNET
|
DSL modem
|
---------- NETGEAR ROUTER --------------------------
| | | | |
mch1 mch2 | mch3 mch5
wxp wxp | Linux Openbsd
|
Netopia router (out=192.168.0.1
| in=192.168.1.1
wirless Serving DHCP to 192.168.1.1-100)
|
Sony Laptop (DHCP)
mch4

The trouble I'm having is getting the laptop (Mch4) to be accessable
to the other windows boxes from network neighborhood.

The laptop can get out to internet ok, and can ping ftp etc to
everything inside.

But I suddenly realized I don't even know how to ping the laptop. It
has a DHCP address. I've never really had any practicl dealings with
DHCP other than an occasional connect to internet from Kinkos or
similar.

[aside]=> Other than getting it off the laptop at the console how do
people get the DHCP addresses of stuff on a lan.

In this case I can get it manually from the console; 192.168.1.100 but
cannot ping it from elsewhere on lan. Even if I set up a static route
on another winxp box like route add 192.168.1.100 192.168.0.1 Still
.... no ping.

That might be that the router is set to block ping by default. I'm
not really eager to delve deeply into that angle.

I hoped someone could list out the normal ways one deals with dhcp
when network troubleshooting.. ie (ping traceroute.. what)
Are there tools that can dig out the dhcp address in use?

 

[GTS]

The ability to access the internet but not the other workstations is exactly
what will happen when you have the two routers both acting as DHCP servers.
Using a wireless router as an Access Point requires assigning it a static
address and turning off it's DHCP function. See
http://www.ezlan.net/router_AP.html for a details on how to configure.

 

[LaManchaDQ]

Also set the Netgear as a Gateway rather than Router and follow GTS' other
suggestion.

The ability to access the internet but not the other workstations is
exactly what will happen when you have the two routers both acting as DHCP
servers. Using a wireless router as an Access Point requires assigning it
a static address and turning off it's DHCP function. See
http://www.ezlan.net/router_AP.html for a details on how to configure.

--

I've always used static addresses inside my home lan until today. I'm
trying to use a netopia router designed for dsl/cable to lan. But
really using it inside the lan only as a wireless access point.

Summary: I need a list of ways normally used to trouble shoot network
when dhcp addresses are in use.

Details:
I've tried many setups but the only one I could get to work so far
that allows me to get what I wanted (a wireless segment inside home
lan)

Looks like : INTERNET
|
DSL modem
|
---------- NETGEAR ROUTER --------------------------
| | | | |
mch1 mch2 | mch3 mch5
wxp wxp | Linux Openbsd
|
Netopia router (out=192.168.0.1
| in=192.168.1.1
wirless Serving DHCP to 192.168.1.1-100)
|
Sony Laptop (DHCP)
mch4

The trouble I'm having is getting the laptop (Mch4) to be accessable
to the other windows boxes from network neighborhood.

The laptop can get out to internet ok, and can ping ftp etc to
everything inside.

But I suddenly realized I don't even know how to ping the laptop. It
has a DHCP address. I've never really had any practicl dealings with
DHCP other than an occasional connect to internet from Kinkos or
similar.

[aside]=> Other than getting it off the laptop at the console how do
people get the DHCP addresses of stuff on a lan.

In this case I can get it manually from the console; 192.168.1.100 but
cannot ping it from elsewhere on lan. Even if I set up a static route
on another winxp box like route add 192.168.1.100 192.168.0.1 Still
... no ping.

That might be that the router is set to block ping by default. I'm
not really eager to delve deeply into that angle.

I hoped someone could list out the normal ways one deals with dhcp
when network troubleshooting.. ie (ping traceroute.. what)
Are there tools that can dig out the dhcp address in use?

 

[Harry Putnam]

The ability to access the internet but not the other workstations is exactly
what will happen when you have the two routers both acting as DHCP servers.
Using a wireless router as an Access Point requires assigning it a static
address and turning off it's DHCP function. See
http://www.ezlan.net/router_AP.html for a details on how to configure.

Maybe my diagram wasn't that clear. If you look you'll notice the
Netgear is not set to serve DHCP. It acquires its IP from the
internet via DHCP from my IP, but it does not serve DHCP to my lan.

the [...]0.1 segment is all static addresses.
From Netgear router downstream.

The netopia router is not recieving a dhcp address. However it is
serving dhcp addresses but only to segment [...]1.1

Only one machine is on the 1.1 network. It is set to get address via
dhcp So the netopia router is static addressed at both ends as in the
diagram but serves dhcp to the one machine.

 

[Harry Putnam]

Also set the Netgear as a Gateway rather than Router and follow GTS' other
suggestion.

The netgear is the gateway for segment [...]0.1.

Doing this another way still arrives at the same problem if dhcp is
used.

Example: I've setup now using a regular Access Point instead of
trying to use the Netopia router. I've assigned all machines static
addresses and all works find. This accesspoing is capable of serving
dhcp. If I choose to use it in dhcp mode, I'd still have the problem
of discovering there IP from a machine upstream. Thats why my summary
said:

 

[GTS]

I did misread, in part, but the problem is essentially the same. Your
putting the Sony on a different subnet (assuming your using a Subnet Mask of
255.255.255.0). If you want to use static addresses and not have the
Netgear act as a DHCP server, you should disable DHCP on the Netopia and
assign both it and the SONY laptop IP addresses in the same 169.100.0.X
range. That's a little unusual, but should work.
--

The ability to access the internet but not the other workstations is
exactly
what will happen when you have the two routers both acting as DHCP
servers.
Using a wireless router as an Access Point requires assigning it a static
address and turning off it's DHCP function. See
http://www.ezlan.net/router_AP.html for a details on how to configure.

Maybe my diagram wasn't that clear. If you look you'll notice the
Netgear is not set to serve DHCP. It acquires its IP from the
internet via DHCP from my IP, but it does not serve DHCP to my lan.

the [...]0.1 segment is all static addresses.
From Netgear router downstream.

The netopia router is not recieving a dhcp address. However it is
serving dhcp addresses but only to segment [...]1.1

Only one machine is on the 1.1 network. It is set to get address via
dhcp So the netopia router is static addressed at both ends as in the
diagram but serves dhcp to the one machine.

 

[Harry Putnam]

I did misread, in part, but the problem is essentially the same. Your
putting the Sony on a different subnet (assuming your using a Subnet Mask of
255.255.255.0). If you want to use static addresses and not have the
Netgear act as a DHCP server, you should disable DHCP on the Netopia and
assign both it and the SONY laptop IP addresses in the same 169.100.0.X
range. That's a little unusual, but should work.

No, it doesn't work... hence my post here.

 

[Harry Putnam]

Let me phrase this another way completely... With a home lan that is
served dhcp, how does one use network places? That is, how to
discover the IP address of a specific machine from a server or some
other central machine?

 

[GTS]

Did you try to access the other workstations by entering \\netname in Run
(or Start \\netname from a command prompt)? If this fails, what error is
reported? Can you ping them (run IP config on the other workstations to
get there address for this)?

Visibility in Network places has limitations. It's not essential to be able
to access another workstation however. If the computers have the same
workgroup name and NetBIOS is enabled, they will usually be visible although
your dual router setup might impact NetBIOS discovery.
--

 

[Chuck]

I've always used static addresses inside my home lan until today. I'm
trying to use a netopia router designed for dsl/cable to lan. But
really using it inside the lan only as a wireless access point.

Summary: I need a list of ways normally used to trouble shoot network
when dhcp addresses are in use.

Details:
I've tried many setups but the only one I could get to work so far
that allows me to get what I wanted (a wireless segment inside home
lan)

Looks like : INTERNET
|
DSL modem
|
---------- NETGEAR ROUTER --------------------------
| | | | |
mch1 mch2 | mch3 mch5
wxp wxp | Linux Openbsd
|
Netopia router (out=192.168.0.1
| in=192.168.1.1
wirless Serving DHCP to 192.168.1.1-100)
|
Sony Laptop (DHCP)
mch4

The trouble I'm having is getting the laptop (Mch4) to be accessable
to the other windows boxes from network neighborhood.

The laptop can get out to internet ok, and can ping ftp etc to
everything inside.

But I suddenly realized I don't even know how to ping the laptop. It
has a DHCP address. I've never really had any practicl dealings with
DHCP other than an occasional connect to internet from Kinkos or
similar.

[aside]=> Other than getting it off the laptop at the console how do
people get the DHCP addresses of stuff on a lan.

In this case I can get it manually from the console; 192.168.1.100 but
cannot ping it from elsewhere on lan. Even if I set up a static route
on another winxp box like route add 192.168.1.100 192.168.0.1 Still
... no ping.

That might be that the router is set to block ping by default. I'm
not really eager to delve deeply into that angle.

I hoped someone could list out the normal ways one deals with dhcp
when network troubleshooting.. ie (ping traceroute.. what)
Are there tools that can dig out the dhcp address in use?

Harry,

If you need to know what ip addresses are used on your LAN at any time, and
examining the DHCP log on your router is not a solution for you, there are any
number of freeware tools that will do a LAN ip scan for you.

I personally, like SoftPerfect Network Scanner
<http://www.softperfect.com/products/networkscanner/>. Also, Angry IPSCanner
<http://www.angryziber.com/ipscan/> deserves examination.

You may want to reconsider your network arrangement too. The way you have
setup, with the wired LAN directly connected to the internet, and the wireless
LAN connected to the wired LAN, has design problems:
1) Any wireless computer can access any wired computer (your wired LAN is
vulnerable to wireless intruders).
2) Your wired computers can't access your wireless computer.

By reversing the arrangement (connecting the wireless LAN directly to the
internet, and the wired LAN to the wireless LAN), these problems would be
resolved.
1) The wired LAN would be protected from the wireless neighborhood, and fromm
the internet in general, by its own router.
2) Computers on the wireless LAN would be accessible from the wired LAN.

The latter solution makes your wireless LAN a true DMZ (protected from the
internet by its router, yet unable to access the doubly protected wired LAN).

--
Cheers,
Chuck
Paranoia comes from experience - and is not necessarily a bad thing.
My email is AT DOT
actual address pchuck sonic net

 

[Chuck]

Let me phrase this another way completely... With a home lan that is
served dhcp, how does one use network places? That is, how to
discover the IP address of a specific machine from a server or some
other central machine?

Harry,

With a simple home LAN, where all computers are running TCP/IP and NetBIOS Over
TCP/IP, and all are on the same LAN, you don't need to explicitly know the ip
address of any of the computers. Name to ip address resolution takes care of
that for you.

Name resolution by peer-to-peer broadcast (ie non-server) works if all computers
are able to communicate with each other. Do "ipconfig /all" from each computer
and examine Node Type. Broadcast / Hybrid / Mixed / Unknown are all compatible.
http://support.microsoft.com/?id=160177

You need to have each computer able to broadcast to each other computer. With
your diagrammed network, your wired and wireless computers won't receive name
broadcasts from each other - the Netopia router will block the broadcasts.

I identified two freeware products, that are capable of discovering ip addresses
on a LAN, in my other reply. Unfortunately, with your wireless and wired
computers on separate LANs, the scanning will only identify computers on that
LAN, not on the other. You'll have to refer to the wireless computer by ip
address.

To access the wireless computer from the wired computers, in addition to
connecting the wired LAN to the wireless LAN (reversing your current
configuration), you'll have to enable LMHosts lookup (TCP/IP Properties -
Advanced - WINS), and put an entry for the wireless computer in each LMHosts
file ("C:\WINDOWS\system32\drivers\etc\lmhosts"), on the wired computers.

--
Cheers,
Chuck
Paranoia comes from experience - and is not necessarily a bad thing.
My email is AT DOT
actual address pchuck sonic net

 

[DLink Guru]

Ok Harry, I see there have been alot of posts to your threads, but no
answers that satisfy you. So Let get the story right here. Please Answer to
my points if im correct or incorrect........

1)Network #1 consists of 4 computers connected to your Netgear router, which
is connected to your broadband connection.
2)You have DHCP disabled on your Netgear Router and have set your 4 systems
to recieve static IPs from the NetGear Router.
3) I am assuming this Network #1 completly works the way you want it to. Am
I correct??????????

4) Now....You Now are connecting a Netopia Router into one of the LAN ports
of your Netgear Router. You have set your Netgear Router to send a Static IP
to the Netopia Router. Correct????????
5) Question???????? Is your Netopia router a Modem/Router Combo or Just a
wireless Router??????
Also, are you connecting your netopia router to your netgear router via your
Netopia LAN Port or its Internet Port????????
6)Your Netopia Router is set for DHCP to just one wireless Laptop, and the
Laptop says it is connected to the router OK......Correct??????

OK..... Now I dont have your origional post, but im guessing you are having
problems access the internet on Network #2. Am I correct???????

Ill get back to you as soon as you get back to me.

Robert.....

The ability to access the internet but not the other workstations is
exactly
what will happen when you have the two routers both acting as DHCP
servers.
Using a wireless router as an Access Point requires assigning it a static
address and turning off it's DHCP function. See
http://www.ezlan.net/router_AP.html for a details on how to configure.

Maybe my diagram wasn't that clear. If you look you'll notice the
Netgear is not set to serve DHCP. It acquires its IP from the
internet via DHCP from my IP, but it does not serve DHCP to my lan.

the [...]0.1 segment is all static addresses.
From Netgear router downstream.

The netopia router is not recieving a dhcp address. However it is
serving dhcp addresses but only to segment [...]1.1

Only one machine is on the 1.1 network. It is set to get address via
dhcp So the netopia router is static addressed at both ends as in the
diagram but serves dhcp to the one machine.

 

[Harry Putnam]

Harry,

With a simple home LAN, where all computers are running TCP/IP and NetBIOS Over
TCP/IP, and all are on the same LAN, you don't need to explicitly know the ip
address of any of the computers. Name to ip address resolution takes care of
that for you.

Name resolution by peer-to-peer broadcast (ie non-server) works if all computers
are able to communicate with each other. Do "ipconfig /all" from each computer
and examine Node Type. Broadcast / Hybrid / Mixed / Unknown are all compatible.
http://support.microsoft.com/?id=160177

You need to have each computer able to broadcast to each other computer. With
your diagrammed network, your wired and wireless computers won't receive name
broadcasts from each other - the Netopia router will block the broadcasts.

I identified two freeware products, that are capable of discovering ip addresses
on a LAN, in my other reply. Unfortunately, with your wireless and wired
computers on separate LANs, the scanning will only identify computers on that
LAN, not on the other. You'll have to refer to the wireless computer by ip
address.

To access the wireless computer from the wired computers, in addition to
connecting the wired LAN to the wireless LAN (reversing your current
configuration), you'll have to enable LMHosts lookup (TCP/IP Properties -
Advanced - WINS), and put an entry for the wireless computer in each LMHosts
file ("C:\WINDOWS\system32\drivers\etc\lmhosts"), on the wired computers.

Chuck, thanks for you professional level answers. You've answered a
number of my unasked questions too, and in general provided a good
boost to understanding this level of networking.

 

[Harry Putnam]

Did you try to access the other workstations by entering \\netname in Run
(or Start \\netname from a command prompt)? If this fails, what error is
reported? Can you ping them (run IP config on the other workstations to
get there address for this)?

GTS, Let me say first that I've moved on to a regular WAP instead of
horsing around with the netopia trying to do something it really isn't
designed for.

Consequently, I haven't tried the above steps you suggest. However
you answers have general applicability. For example simply showing a
simple way to test things with \\netname has been very helpfull and
including your other posts on this provide a sort of series of bits of
info that will be usefull in lots of places for me.

Thanks

Visibility in Network places has limitations. It's not essential to be able
to access another workstation however. If the computers have the same
workgroup name and NetBIOS is enabled, they will usually be visible although
your dual router setup might impact NetBIOS discovery.

I believe now that the netopia simply is not going to do what I
wanted. Except possibly when used as a simple hub (ignoring the IP in
port) and just using the ethernet ports to connect stuff.

I was still curious about having the wap serving dhcp, but I see now
its really just sort of a retorical (non-usefull) idea. If I want
dhcp then use the lead router. In this case I don't really want dhcp,
it only came up because it seemed necessary to be able to use the
netopia for the use I diagramed.

I think I'll reserve the Netopia as a backup for the Netgear main
router. That is, let it set on shelf and use it for the main router if
need be, and use a regular wap for the wireless segment.

Thanks to all for the helpfull pointers

 

[Chuck]

Chuck, thanks for you professional level answers. You've answered a
number of my unasked questions too, and in general provided a good
boost to understanding this level of networking.

Thanks for your feedback, Harry. We'll be here for a long time, so keep asking
questions. Everybody learns here.

If you're going to use a WAP, please firewall all computers connected to your
LAN. The wireless world is full of obnoxious people - don't leave your wired
computers vulnerable.

Stay safe.

--
Cheers,
Chuck
Paranoia comes from experience - and is not necessarily a bad thing.
My email is AT DOT
actual address pchuck sonic net

 

[GTS]

You're welcome. It was a good move to go for the simpler solution in the
end.
--

 

[Harry Putnam]

Ok Harry, I see there have been alot of posts to your threads, but no
answers that satisfy you. So Let get the story right here. Please Answer to
my points if im correct or incorrect........

1)Network #1 consists of 4 computers connected to your Netgear router, which
is connected to your broadband connection.
Yes

2)You have DHCP disabled on your Netgear Router and have set your 4 systems
to recieve static IPs from the NetGear Router.

Well I type in the static IP at each console

3) I am assuming this Network #1 completly works the way you want it to. Am
I correct??????????
Yes

4) Now....You Now are connecting a Netopia Router into one of the LAN ports
of your Netgear Router. You have set your Netgear Router to send a Static IP
to the Netopia Router. Correct????????

I've typed in a static address on the Netopia

5) Question???????? Is your Netopia router a Modem/Router Combo or Just a
wireless Router??????

Modem/router combo

Also, are you connecting your netopia router to your netgear router via your
Netopia LAN Port or its Internet Port????????

Internet port

6)Your Netopia Router is set for DHCP to just one wireless Laptop, and the
Laptop says it is connected to the router OK......Correct??????
Yes

OK..... Now I dont have your origional post, but im guessing you are having
problems access the internet on Network #2. Am I correct???????

Incorrect. No problems getting the INTERNET from 2nd subnet. The
problem is getting to the other computers on the lan.

But before you spend more of your valuable time further on this, know
that I've scrapped the notion of trying to make the Netopia do things
it isn't desinged for and inserted a regular WAP in its place.
Everthing static everthing on same subnet. All is hunky dorey.

 

[DLink Guru]

OK, thats cool.... But the one thing you really have to do if you want to
connect to the other systems is open all the ports in the Netopia router so
it will appear as just a hub/switch. With the built in firewall enabled, you
will not have access to any other system on the WAN side of the router.

Robert...