3 segment wireless network

J

johnmclaren_99

sorry for posting here, this probably isn't the place, but the no one
else knows how to handle this problem.
i have a 3 segment network spread over a large office.

segment 1 consists of a wireless router named linksys. it is the
default gateway to the internet.

segments 2 and 3 consist of a wireless ap and a bridge.

computers on segment 1 can see computers on segments 2 and 3 and vice
versa.

computers on segments 2 and 3 can not see each other.

the way that i thought this was supposed to be set up and work was...

segments 2 and 3 have different ssids and use a bridge to connect to
segment 1, and, thus, each other.

am i right in thinking this?
 
C

Chuck

sorry for posting here, this probably isn't the place, but the no one
else knows how to handle this problem.
i have a 3 segment network spread over a large office.

segment 1 consists of a wireless router named linksys. it is the
default gateway to the internet.

segments 2 and 3 consist of a wireless ap and a bridge.

computers on segment 1 can see computers on segments 2 and 3 and vice
versa.

computers on segments 2 and 3 can not see each other.

the way that i thought this was supposed to be set up and work was...

segments 2 and 3 have different ssids and use a bridge to connect to
segment 1, and, thus, each other.

am i right in thinking this?

John,

You have an interesting question, and one which I think needs to be broken down
a bit.

The SSID, used to identify WiFi networks, can be different (on multiple APs in a
network) if you wish to separate network traffic. If you wish to allow roaming
(automatic use of the different APs based upon location or availability), you
can also make the SSIDs the same.

The SSID should not control visibility of the computers between each other,
whether connected thru the same, or different, APs.

If all of the computers have Internet connectivity, or any other identifiable
network connectivity, then visibility is not a WiFi issue, just a symptom.
Visibility is a matter of connectivity, domain or workgroup membership, and
browser visibility (and I'm not discussing Internet Explorer here).

How is your network setup? Are segments 1, 2, and 3 on the same, or different
subnets? Do you have a domain (multiple domains)? Or a workgroup (multiple
workgroups)? Or a mixture? The answer to those questions will determine how we
research your problems.
 
M

Mr Critter

I agree with Chuck. Once your computers have connected to their
associated LAN with their SSID, wireless shouldn't be a factor for
troubleshooting purposes. Are they all on the same network (i.e. IP
range, mask) and Windows association (workgroup, domain, etc.)? What
kind of AP's are you using (Aironet, Linksys, D-Link, etc.), and are
you using any VLANS? What IP addresses and masks are you using for
each node? Many variables.

Mr. Crittenden, MS
 
J

johnmclaren_99

well, they are all on the same subnet 192.168.1 and use the same mask..
255.255.255.0
they are also on the same workgroup. the access points are linksys g
access points. wap54. they are connected directly via cat5e to wet54g
(bridges) the bridge is connected to a linksys wireless router via it's
wireless bridge...

I recently called linksys and they informed me that the two segments
can't see each other because the wireless part of the wireless router
isn't capable of switching packets between the two segments. i find
that strange, because if that were the case, why can it switch packets
between computers, but i don't entirely discredit the tech. wouldn't be
the first time that they didn't follow the rules of networking.

setting that asside, the network is on the same subnet and uses the
same workgroup. there seems to be some problem with the wireless router
switching the packets. now, if i eliminate the router, take a switch,
wire cat5e into 2 bridges and connect each to segments 2 and 3, would
that work? would the two segments be able to see each other?
 
C

Chuck

well, they are all on the same subnet 192.168.1 and use the same mask..
255.255.255.0
they are also on the same workgroup. the access points are linksys g
access points. wap54. they are connected directly via cat5e to wet54g
(bridges) the bridge is connected to a linksys wireless router via it's
wireless bridge...

I recently called linksys and they informed me that the two segments
can't see each other because the wireless part of the wireless router
isn't capable of switching packets between the two segments. i find
that strange, because if that were the case, why can it switch packets
between computers, but i don't entirely discredit the tech. wouldn't be
the first time that they didn't follow the rules of networking.

setting that asside, the network is on the same subnet and uses the
same workgroup. there seems to be some problem with the wireless router
switching the packets. now, if i eliminate the router, take a switch,
wire cat5e into 2 bridges and connect each to segments 2 and 3, would
that work? would the two segments be able to see each other?

John,

Correct me if I'm wrong. You have 1 router (what model), connected to segment
1. All of the other hardware is just bridges and hubs (APs). Unless the router
had "Isolation Mode" on (check for that please), its LAN is simply a switch - no
need to add a switch.

Let's eliminate the possibilities here. Is the only problem that the computers
in each segment can't see each other in My Network Places? Or is it something
deeper? Can you ping computers between segment? By name? By IP address?

Look at "browstat status" and "ipconfig /all", from 3 computers, one from each
segment, so we can diagnose the problem. Read this article, and linked
articles, and follow instructions precisely (download browstat!):
<http://nitecruzr.blogspot.com/2005/05/troubleshooting-network-neighborhood.html#AskingForHelp>
http://nitecruzr.blogspot.com/2005/05/troubleshooting-network-neighborhood.html#AskingForHelp
 
J

johnmclaren_99

chuck, the way that it is setup now, the computers in segment 1 can see
the computers in segments 2 and 3, however, computers in segments 2 and
3 can not see each oter. the bridges are attached to the ap's for
segments 2 and 3 via cat5e, then attached to segment 1 via wireless
bridge. logically, i would think the same as you would; the router
contains a built in switch, so it must switch wireless traffic, across
2 segments, as well; however, the linksys tech tells me different. and
encryption is turned off... i'm not sure what the model number is,
right off hand. i will have to tell you tomorrow (monday) and i don't
think it has isolation mode, although that's something i didn't think
of and will check.

to answer your question directly, the computers in segments 2 and 3
have no connectivity to each other be it ping or network neighborhood.
i can't ping the bridges or the ap's from 2 to 3 or reverse, so the
problem, most likely, is in the router. that's why i'm thinking that
connecting 2 bridges via a wired switch will resolve this problem.

their ipconfig/all says:
dhcp
192.168.1.107,104,110
255.255.255.0
gw 192.168.1.1
dns 192.168.1.1

does it theoretically make sense that if i link the segments together,
as stated before, those segments will be able to see each other?
 
C

Chuck

chuck, the way that it is setup now, the computers in segment 1 can see
the computers in segments 2 and 3, however, computers in segments 2 and
3 can not see each oter. the bridges are attached to the ap's for
segments 2 and 3 via cat5e, then attached to segment 1 via wireless
bridge. logically, i would think the same as you would; the router
contains a built in switch, so it must switch wireless traffic, across
2 segments, as well; however, the linksys tech tells me different. and
encryption is turned off... i'm not sure what the model number is,
right off hand. i will have to tell you tomorrow (monday) and i don't
think it has isolation mode, although that's something i didn't think
of and will check.

to answer your question directly, the computers in segments 2 and 3
have no connectivity to each other be it ping or network neighborhood.
i can't ping the bridges or the ap's from 2 to 3 or reverse, so the
problem, most likely, is in the router. that's why i'm thinking that
connecting 2 bridges via a wired switch will resolve this problem.

their ipconfig/all says:
dhcp
192.168.1.107,104,110
255.255.255.0
gw 192.168.1.1
dns 192.168.1.1

does it theoretically make sense that if i link the segments together,
as stated before, those segments will be able to see each other?

John,

If you connect the 3 segments properly, all computers should be able to ping,
and to see, each other. Most NAT routers have only a switch connecting their
LAN ports. Let's look at the router make and model, though, before guessing.
 
J

johnmclaren_99

chuck, i have eliminated the wireless router all together. i opted for
a wired version. this seems to have resolved the inner office network
connectivity.

the network is as follows...

cable modem > BEFSX41(Router) > EZXS55W (Switch) > wet54g (bridge) >>
wap54g (WAP) >> adapter
that's for segment linksys3

cable modem > BEFSX41> EZXS55W> wet11 >>wap11b >> adapter
for segment 2

segment 1 has been eliminated, for the time being.

new problem as follows:

all segments can see each other. segment 2 can see out past the router
via ping, without any drops, however, when browsing, it is spuratic.

segment 3 can not see past the router, at all. it can't even see the
external ip address of the router.

the linksys people (idiots) told me that it's set up wrong and the
problem was the configuration of the bridges because bridges can only
transmit, not receive. what?!!

when i told him that if that were the case, why was i receiving a ping
reply from the default gateway, he said that he was going to have to
look into that one, put me on hold, and hung up.

any ideas, now?
 
C

Chuck

chuck, i have eliminated the wireless router all together. i opted for
a wired version. this seems to have resolved the inner office network
connectivity.

the network is as follows...


cable modem > BEFSX41(Router) > EZXS55W (Switch) > wet54g (bridge) >>
wap54g (WAP) >> adapter
that's for segment linksys3

cable modem > BEFSX41> EZXS55W> wet11 >>wap11b >> adapter
for segment 2

segment 1 has been eliminated, for the time being.

new problem as follows:

all segments can see each other. segment 2 can see out past the router
via ping, without any drops, however, when browsing, it is spuratic.

segment 3 can not see past the router, at all. it can't even see the
external ip address of the router.

the linksys people (idiots) told me that it's set up wrong and the
problem was the configuration of the bridges because bridges can only
transmit, not receive. what?!!

when i told him that if that were the case, why was i receiving a ping
reply from the default gateway, he said that he was going to have to
look into that one, put me on hold, and hung up.

any ideas, now?

John,

I'm still a bit confused about the bridges and APs myself, so I can't totally
fault the Linksys techs. I'd like to help you here, but you seem to have some
ideas of your own, and they don't seem to totally agree with mine. But your
diagram gives me some idea where we are, so let's get started.

We'll take this setup as our baseline, and work from here.

One of the challenges of WiFi is that it's a shared medium. Only one device
(computer or router) can transmit at any time. Depending upon the ability of
segments 2 and 3 components (any components) to detect each others presence,
this will make problems. Please read several of my articles, for background
here.
<http://nitecruzr.blogspot.com/2006/02/set-of-simple-network-components.html#WiFi>
http://nitecruzr.blogspot.com/2006/02/set-of-simple-network-components.html#WiFi
<http://nitecruzr.blogspot.com/2005/11/setting-up-wifi-lan.html>
http://nitecruzr.blogspot.com/2005/11/setting-up-wifi-lan.html
<http://nitecruzr.blogspot.com/2006/05/you-have-to-share-wifi-bandwidth.html>
http://nitecruzr.blogspot.com/2006/05/you-have-to-share-wifi-bandwidth.html
<http://nitecruzr.blogspot.com/2005/10/wifi-will-never-be-as-fast-as-ethernet.html>
http://nitecruzr.blogspot.com/2005/10/wifi-will-never-be-as-fast-as-ethernet.html

The above articles describe problems with basic network connectivity, like the
ability of any computer to ping another. When you get to the ability of any
computer to see another in My Network Places, we're getting to another favourite
subject of mine - the browser.
<http://nitecruzr.blogspot.com/2005/04/nt-browser-or-why-cant-i-always-see.html>
http://nitecruzr.blogspot.com/2005/04/nt-browser-or-why-cant-i-always-see.html

Now it is time for details.
# How many computers are in each segment?
# For each segment, how many computers would typically be accessed by computers
in the other 2 segments?
# Do any computers use any protocols other than IP? Do any use NetBEUI or
IPX/SPX?
# Please describe the physical layout of the segments - distance between each
network component, and how many walls and ceilings (and what the building is
constructed) separate each, are going to be very important.
# Please read the above articles, to understand why these details are relevant.
 
J

johnmclaren_99

chuck, i understand all of this; i'm not a noob.

there are no more than 7 computers in segment 2. there are 4 in
segment 3

i would say that no more than 2 computers would be accessing each other
at the same time, throughout the network, and there would probably be
no more than 5 computers on the internet at the same time... at the
most (worst case)

everything runs tcp/ip
 
C

Chuck

chuck, i understand all of this; i'm not a noob.

there are no more than 7 computers in segment 2. there are 4 in
segment 3

i would say that no more than 2 computers would be accessing each other
at the same time, throughout the network, and there would probably be
no more than 5 computers on the internet at the same time... at the
most (worst case)

everything runs tcp/ip

John,

I know you're not a noob. But more detail might be useful here. And you keep
deleting my previous remarks, so I have to go back manually to review what I've
already said. This makes this whole process harder for me, and makes me make
mistakes, which is bad for you.

Let me describe a problem, greatly simplified (I can only type so fast).

You have 2 networks, connected by WiFi to a third network. Now since WiFi is a
shared medium, Computers A (on network A) and B (on network B) have to wait for
each other to finish, before sending anything to Router C (on network C).

This works OK for Internet transactions. Users on Computers A and B are surfing
the Internet asynchronously.
# User A sends a request for website D, to Router C. Computer B has to wait.
# While Router C is sending to Computer D (on the Internet), Computer B can send
a request for Website E, to Router C.
# Router C gets back a web page from Computer D, and sends it to Computer A.
Simultaneously, it's sending to Computer E (on the Internet).
# Router C gets back a web page from Computer E, and sends it to Computer B.
# Simultaneously, User A has requested web page F, and is waiting. As soon as
Computer B has web page E, Computer A is requesting web page F.
# And so on. This works for two reasons:
1) User A can be reading a web page while Computer B is requesting one.
Computers A and B are sharing the channel.
2) When Computer A is sending to Computer D, Computer D is upstream from Router
C, and connected by wired networks. Lots of wired networks. The WiFi link has
just 1 component: Computer A to Router C.

What happens if User A is getting a file from Computer B? A file will consist
of many packets of data, all coming from the other computer.
# Computer A sends a request to Computer B, thru Router C. Now you have a
request relayed by Router C, using WiFi BOTH WAYS. This is not too bad, though,
yet.
# Computer B sends back 1 packet of the file to Router C.
# Router C sends the packet to Computer A. Computer B has to wait before
sending a second packet.
# Uh oh. Computer A needs to send a thank you to Computer B, and ask for
another packet. The thank you goes from Computer A to Router C.
# Router C sends the thank you on to Computer B.
# Computer B sends the second packet to Router C.
# Router C sends the second packet on to Computer A.
# And so on. This is a slow process. Compared to the first example,
1) Computer B is sending to Computer A, supposedly continuously. No break in
the action, with a person viewing anything and making a decision.
2) When Computer B is sending to Computer A, Computer A is upstream from Router
C. The WiFi link has 2 components: Computer B to Router C, and Router C to
Computer A.

Now what happens if only Router C can see both Computers A and B? This is
called a hidden node problem. Since Computers A and B don't know each other is
there (on the channel), they keep sending simultaneously. Router C has to keep
telling one to shut up, when the other is sending, or keep dealing with the
problem of interference.
<http://en.wikipedia.org/wiki/Hidden_node_problem>
http://en.wikipedia.org/wiki/Hidden_node_problem

And add 3 more computers (you said a total of 5 accessing the Internet) while 2
are communicating with each other. All having to share that one WiFi channel.
Read about CSMA/CA please.

Now my apologies for writing stuff that you already know, but having only read 4
posts from you, I'm not sure what you do know and what you don't. You're asking
for help here, and I'm trying to help.

Anyway, after we get thru this problem, we'll get to the browser issue. And why
WiFi and the browser don't work well either.
 
J

johnmclaren_99

chuck, i don't know if this is better, or not...regarding the post...
it's on google's groups, so if you are reading it in microsofts groups,
it may mess with things...

here is the google website...
http://groups.google.com/group/micr.../browse_thread/thread/6d2adbde02432bd1/?hl=en

i completely understand what you are telling me, i just never actually
thought of that until now. gets pretty messy... I think that they are
about at their limitation for what they can do wirelessly. i may have
to just put my foot down and tell them to go wired. i realy appreciate
your help, chuck.if you have any problems, my name is really
christopher. you can send me an email to
(e-mail address removed) if you ever need any advise, or to seek
a second opinion, just as i did...
 
C

Chuck

chuck, i don't know if this is better, or not...regarding the post...
it's on google's groups, so if you are reading it in microsofts groups,
it may mess with things...

here is the google website...
http://groups.google.com/group/micr.../browse_thread/thread/6d2adbde02432bd1/?hl=en

i completely understand what you are telling me, i just never actually
thought of that until now. gets pretty messy... I think that they are
about at their limitation for what they can do wirelessly. i may have
to just put my foot down and tell them to go wired. i realy appreciate
your help, chuck.if you have any problems, my name is really
christopher. you can send me an email to
(e-mail address removed) if you ever need any advise, or to seek
a second opinion, just as i did...

Hi Christopher,

OK, you're getting the picture. WiFi is just not a good replacement for
Ethernet, which is where my article started.
<http://nitecruzr.blogspot.com/2005/10/wifi-will-never-be-as-fast-as-ethernet.html>
http://nitecruzr.blogspot.com/2005/10/wifi-will-never-be-as-fast-as-ethernet.html

Then you add in the browser, and a possible master browser conflict caused by a
WiFi server losing contact with the other servers.
<http://nitecruzr.blogspot.com/2005/04/nt-browser-or-why-cant-i-always-see.html#Differences>\
http://nitecruzr.blogspot.com/2005/04/nt-browser-or-why-cant-i-always-see.html#Differences

That said, we can tune the setup somewhat. We're not done - at least I'm not.

You might start with a site survey using NetStumbler. See where your blind
spots are.
<http://nitecruzr.blogspot.com/2005/05/essential-tools-for-desktop-and.html#NetStumbler>
http://nitecruzr.blogspot.com/2005/05/essential-tools-for-desktop-and.html#NetStumbler

Maybe put segments 2 and 3 on different channels.

Still seeing unbalanced results on segments 2 and 3? You're using different
hardware - segment 2 has a WAP11b, segment 3 has a WAP54g. Note my issues about
802.11g, which has more WiFi neighbours (3 802.11b channels), and possibly more
channel contention, and waiting. Can you run the WAP54g in B-mode?

And for heavens sake, tune the browser setup. Again, we need an inventory here.
How many computers on each segment? How many online at any time? How much
cross-segment traffic as opposed to same segment traffic? How many computers
stay online (powered up and connected) 7 x 24 on each segment? Is this a domain
or workgroup? If a workgroup, consider a domain, which can handle browsing in a
multi-segment environment better.
<http://nitecruzr.blogspot.com/2005/08/setting-up-domain-or-workgroup-plan.html>
http://nitecruzr.blogspot.com/2005/08/setting-up-domain-or-workgroup-plan.html
 

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