Expanding Wireless coverage by cascading APs

We have one of common Wireless AP/Router with 4 wired ports,
LinkSys BEFW11S4. We would like to expand its wireless coverage.
Here is what we plan to do:

- Keep current AP/Router as the central AP/Router connected to WAN
- Buy 4 more similar AP/Routers
- Connect these ancillary APs to central one using wired LAN ports
- Disable DHCP servers of all the ancillary APs, keep the central
- Operate all the 5 APs at different frequency channels
- Set a different SSID on all the 5 APs

I see at least one problem - all the APs will be running internal
Web servers at IP=192.168.1.1 and that all the APs will be on the
same LAN, there will be address conflict. How can we fix this?
Do you see any other technical problem or have comments on above plan?

Thanks,
Vinod Gupta

This may sound obvious but don't connect them straight away and
configure each on seperatley (either using a laptop or plugging it into
one ocmputer) before you link them together.

I'm not sure on that model but you should be able to change the internal
address of the web server. 1.2,1.3,1.4 etc....

We have around 20 AP's in use in this fashion with a mix of both d-link
& cicso AP's

Vinod Gupta wrote:

> We have one of common Wireless AP/Router with 4 wired ports,
> LinkSys BEFW11S4. We would like to expand its wireless coverage.
> Here is what we plan to do:
>
> - Keep current AP/Router as the central AP/Router connected to WAN
> - Buy 4 more similar AP/Routers
> - Connect these ancillary APs to central one using wired LAN ports
> - Disable DHCP servers of all the ancillary APs, keep the central
> - Operate all the 5 APs at different frequency channels
> - Set a different SSID on all the 5 APs
>
> I see at least one problem - all the APs will be running internal
> Web servers at IP=192.168.1.1 and that all the APs will be on the
> same LAN, there will be address conflict. How can we fix this?
> Do you see any other technical problem or have comments on above plan?
>
> Thanks,
> Vinod Gupta

(E-Mail Removed) (Vinod Gupta) wrote in message news:<(E-Mail Removed) om>...
> We have one of common Wireless AP/Router with 4 wired ports,
> LinkSys BEFW11S4. We would like to expand its wireless coverage.
> Here is what we plan to do:
>
> - Keep current AP/Router as the central AP/Router connected to WAN
> - Buy 4 more similar AP/Routers
> - Connect these ancillary APs to central one using wired LAN ports

APs are not designed for that. You need wireless bridges.

> - Disable DHCP servers of all the ancillary APs, keep the central
> - Operate all the 5 APs at different frequency channels

You can only use 3 sets of frequencies reliabily, before running into interfences.

> - Set a different SSID on all the 5 APs
>
> I see at least one problem - all the APs will be running internal
> Web servers at IP=192.168.1.1 and that all the APs will be on the
> same LAN, there will be address conflict. How can we fix this?

Not with the linksys box, can't fix it.

> Do you see any other technical problem or have comments on above plan?

Sound too good to be true (or working).

>
> Thanks,
> Vinod Gupta

On 25 Apr 2004 09:10:25 -0700, Vinod Gupta <(E-Mail Removed)> wrote:
> We have one of common Wireless AP/Router with 4 wired ports,
> LinkSys BEFW11S4. We would like to expand its wireless coverage.
> Here is what we plan to do:
>
> - Keep current AP/Router as the central AP/Router connected to WAN
> - Buy 4 more similar AP/Routers
> - Connect these ancillary APs to central one using wired LAN ports
> - Disable DHCP servers of all the ancillary APs, keep the central
> - Operate all the 5 APs at different frequency channels
> - Set a different SSID on all the 5 APs

Unless you specifically want to isolate each LAN as a different subnet
behind each router, you likely want AP's for the other ones for one big
network, instead of AP/Routers. If they are all NAT routers, then a box
on 1 router will not be able to directly contact a box behind another
router (without specific port forwarding or destination set as DMZ on its
router). In some cases broadband routers can be dumbed down (dhcp
disabled, and connected with uplink port or crossover cable LAN2LAN as one
network with nothing on WAN), but that may not work too well in some cases
(my SMC wireless router caused frequent 5-10 second arp delays when used
that way).

> I see at least one problem - all the APs will be running internal
> Web servers at IP=192.168.1.1 and that all the APs will be on the
> same LAN, there will be address conflict. How can we fix this?
> Do you see any other technical problem or have comments on above plan?

Whether you use AP or AP/router, you should be able to change its LAN IP.
Adjacent AP's should be set at least 5 channels apart. So if one uses
channel 6, the closest ones to it should use 1 or 11.

--
David Efflandt - All spam ignored http://www.de-srv.com/

(E-Mail Removed) (David Efflandt) wrote in message news:<(E-Mail Removed)>...
> On 25 Apr 2004 09:10:25 -0700, Vinod Gupta <(E-Mail Removed)> wrote:
> > We have one of common Wireless AP/Router with 4 wired ports,
> > LinkSys BEFW11S4. We would like to expand its wireless coverage.
> > Here is what we plan to do:
> >
> > - Keep current AP/Router as the central AP/Router connected to WAN
> > - Buy 4 more similar AP/Routers
> > - Connect these ancillary APs to central one using wired LAN ports
> > - Disable DHCP servers of all the ancillary APs, keep the central
> > - Operate all the 5 APs at different frequency channels
> > - Set a different SSID on all the 5 APs
>
> Unless you specifically want to isolate each LAN as a different subnet
> behind each router, you likely want AP's for the other ones for one big
> network, instead of AP/Routers. If they are all NAT routers, then a box
> on 1 router will not be able to directly contact a box behind another
> router (without specific port forwarding or destination set as DMZ on its
> router). In some cases broadband routers can be dumbed down (dhcp
> disabled, and connected with uplink port or crossover cable LAN2LAN as one
> network with nothing on WAN), but that may not work too well in some cases
> (my SMC wireless router caused frequent 5-10 second arp delays when used
> that way).

I was planning on using the LAN ports precisely for this reason.
Router/DHCP_Server/NAT components of ancillary AP/Routers should be out of
picture. I can't think of other functional component, except Web server,
could cause conflicts. In the mean time I have been reading some LinkSys docs.
It says that their APs can be used to extend range when used in "AP Client"
mode and it must be paired with LinkSys models only. Never heard of APs also
have different operational modes!

Vinod

(E-Mail Removed) (Edward Lee epl) wrote in message news:<(E-Mail Removed) om>...
> (E-Mail Removed) (Vinod Gupta) wrote in message news:<(E-Mail Removed) om>...
> > We have one of common Wireless AP/Router with 4 wired ports,
> > LinkSys BEFW11S4. We would like to expand its wireless coverage.
> > Here is what we plan to do:
> >
> > - Keep current AP/Router as the central AP/Router connected to WAN
> > - Buy 4 more similar AP/Routers
> > - Connect these ancillary APs to central one using wired LAN ports
>
> APs are not designed for that. You need wireless bridges.

I think I will definitely need AP functionality at each of the 4 ancillary
nodes. Not sure if wireless bridges can perform this function.

> > I see at least one problem - all the APs will be running internal
> > Web servers at IP=192.168.1.1 and that all the APs will be on the
> > same LAN, there will be address conflict. How can we fix this?
>
> Not with the linksys box, can't fix it.

That is definitely a bad news. Does any one know other APs in which the
Web server IP could be changed?

Vinod

On 26 Apr 2004 05:31:14 -0700, Vinod Gupta <(E-Mail Removed)> wrote:
> (E-Mail Removed) (David Efflandt) wrote in message news:<(E-Mail Removed)>...
>> On 25 Apr 2004 09:10:25 -0700, Vinod Gupta <(E-Mail Removed)> wrote:
>> > We have one of common Wireless AP/Router with 4 wired ports,
>> > LinkSys BEFW11S4. We would like to expand its wireless coverage.
>> > Here is what we plan to do:
>> >
>> > - Keep current AP/Router as the central AP/Router connected to WAN
>> > - Buy 4 more similar AP/Routers
>> > - Connect these ancillary APs to central one using wired LAN ports
>> > - Disable DHCP servers of all the ancillary APs, keep the central
>> > - Operate all the 5 APs at different frequency channels
>> > - Set a different SSID on all the 5 APs
>>
>> Unless you specifically want to isolate each LAN as a different subnet
>> behind each router, you likely want AP's for the other ones for one big
>> network, instead of AP/Routers. If they are all NAT routers, then a box
>> on 1 router will not be able to directly contact a box behind another
>> router (without specific port forwarding or destination set as DMZ on its
>> router). In some cases broadband routers can be dumbed down (dhcp
>> disabled, and connected with uplink port or crossover cable LAN2LAN as one
>> network with nothing on WAN), but that may not work too well in some cases
>> (my SMC wireless router caused frequent 5-10 second arp delays when used
>> that way).
>
> I was planning on using the LAN ports precisely for this reason.
> Router/DHCP_Server/NAT components of ancillary AP/Routers should be out of
> picture. I can't think of other functional component, except Web server,
> could cause conflicts. In the mean time I have been reading some LinkSys docs.
> It says that their APs can be used to extend range when used in "AP Client"
> mode and it must be paired with LinkSys models only. Never heard of APs also
> have different operational modes!

If you are going to dumb down an AP/router to just act as a switch and AP,
an AP (and switch as needed) may work better (it did in my case). I am
using an older WAP11 v2.2 and it can act as AP (so wireless clients can
connect), wireless client (to connect to an AP), or wireless bridge or
multi-bridge (bridges wired networks, but only works between other Linksys
WAP's and does not provide any other wireless access). The newer Linksys
WAP's can also act as wireless repeater (to extend range of central AP by
receiving/retransmitting).

So you first need to be clear whether you want to wire additional points
of connection for wireless clients (AP only), wirelessly extend range
(repeater), or wireless bridge wired networks together (which would NOT
provide AP function).

--
David Efflandt - All spam ignored http://www.de-srv.com/

(E-Mail Removed) (Vinod Gupta) wrote in message news:<(E-Mail Removed) om>...
> We have one of common Wireless AP/Router with 4 wired ports,
> LinkSys BEFW11S4. We would like to expand its wireless coverage.
> Here is what we plan to do:
>
> - Keep current AP/Router as the central AP/Router connected to WAN
> - Buy 4 more similar AP/Routers
> - Connect these ancillary APs to central one using wired LAN ports
> - Disable DHCP servers of all the ancillary APs, keep the central
> - Operate all the 5 APs at different frequency channels
> - Set a different SSID on all the 5 APs
>
> I see at least one problem - all the APs will be running internal
> Web servers at IP=192.168.1.1 and that all the APs will be on the
> same LAN, there will be address conflict. How can we fix this?
> Do you see any other technical problem or have comments on above plan?
>
> Thanks,
> Vinod Gupta

Thanks for all those who responded. Let me redescribe the plan and the
problem with the help of a crude diagram that follows the text.

The fundamental objective is to provide widest possible wireless
coverage for the laptops roaming in the building, we must have AP
functionality at the ends. Repeaters sound most obvious choice except
that all the points are separated by several concrete walls, some points
may receive no signal to repeat. Also, since client AP (repeater) talks
P2P to the central AP, not sure if one central can talk to multiple
client APs, or a client AP can be repeated by another client AP.

My plan is to use the following architecture. Remote AP/Routers (only
two shown) have their Router/NAT unused and DHCP servers disabled.
They are all on the same LAN.

There is a problem if the conflicting IPs of the Web servers can not
be changed. Web servers can not (and should not) be disabled to
configure each unit.

Not sure why some people are suggesting using Bridges (won't get
AP functionality at the ends) or AP-only devices which in our
local market cost more than Router/AP. Moreover, if AP-only devices
also run config web server at the same and unmodifiable IP, they
will suffer from the above refered problem.

I know that some of you out there have actually succeeded in doing
this...just don't know how? So, still looking for some more help.

Vinod


+----------+
| Disabled |
+-------+--+ Remote AP Y
| |
+------------+ +-+----------+ +------+ |
----| Un-used |---------| LAN-Switch |---| AP |---+
+------------+ +-+-------+--+ +------+
| |
+-------+-+ |
| Web Srv | |
+---------+ |
192.168.1.1 |
|
|
====================================|============= =======
Concrete walls |
|
+----------+ |
| DHCP Srv | |
+-------+--+ | Central AP Y
| | |
+------------+ +-+-------+--+ +------+ |
----| Router+NAT |---------| LAN-Switch |---| AP |---+
WAN +------------+ +-+-------+--+ +------+
| |
+-------+-+ |
| Web Srv | |
+---------+ |
192.168.1.1 |
|
|
====================================|============= =======
Concrete walls |
|
|
|
+----------+ |
| Disabled | |
+-------+--+ | Remote AP Y
| | |
+------------+ +-+-------+--+ +------+ |
----| Un-used |---------| LAN-Switch |---| AP |---+
+------------+ +-+----------+ +------+
|
+-------+-+
| Web Srv |
+---------+
192.168.1.1