Router not working in one direction

Hi.

I have the following network setup: 2 wired networks, plus a wireless
connection between the two (it's too long to run cable). On one
network, call it network #1, I have a Linux computer set up as a
router, and it contains a wireless and a wired network card. The other
network, network #2, has a DSL modem which is used as both an Ethernet
wired hub and as a wireless transmitter.

But there's a problem: I can contact the computers on network #2 from
#1, but not the other way around, although interestingly I can contact
the router's wired interface (address 192.168.0.254, which is on
network #1). Why is that?

The routing table on the router looks like this, if you need it:
Destination Gateway Genmask Flags MSS Window
irtt Iface
192.168.0.0 * 255.255.255.0 U 0 0
0 eth0
192.168.254.0 * 255.255.255.0 U 0 0
0 wlan0
link-local * 255.255.0.0 U 0 0
0 eth0
loopback * 255.0.0.0 U 0 0
0 lo
default 192.168.254.254 0.0.0.0 UG 0 0
0 wlan0

On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
> Hi.
>
> I have the following network setup: 2 wired networks, plus a wireless
> connection between the two (it's too long to run cable). On one
> network, call it network #1, I have a Linux computer set up as arouter, and it contains a wireless and a wired network card. The other
> network, network #2, has a DSL modem which is used as both an Ethernet
> wired hub and as a wireless transmitter.
>
> But there's a problem: I can contact the computers on network #2 from
> #1, but not the other way around, although interestingly I can contact
> therouter'swired interface (address 192.168.0.254, which is on
> network #1). Why is that?
>
> The routing table on therouterlooks like this, if you need it:
> Destination Gateway Genmask Flags MSS Window
> irtt Iface
> 192.168.0.0 * 255.255.255.0 U 0 0
> 0 eth0
> 192.168.254.0 * 255.255.255.0 U 0 0
> 0 wlan0
> link-local * 255.255.0.0 U 0 0
> 0 eth0
> loopback * 255.0.0.0 U 0 0
> 0 lo
> default 192.168.254.254 0.0.0.0 UG 0 0
> 0 wlan0

Any answers? I've read some stuff about this but haven't found
anything.

mike3 wrote:
> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
>> Hi.
>>
>> I have the following network setup: 2 wired networks, plus a wireless
>> connection between the two (it's too long to run cable). On one
>> network, call it network #1, I have a Linux computer set up as arouter, and it contains a wireless and a wired network card. The other
>> network, network #2, has a DSL modem which is used as both an Ethernet
>> wired hub and as a wireless transmitter.
>>
>> But there's a problem: I can contact the computers on network #2 from
>> #1, but not the other way around, although interestingly I can contact
>> therouter'swired interface (address 192.168.0.254, which is on
>> network #1). Why is that?
>>
>> The routing table on therouterlooks like this, if you need it:
>> Destination Gateway Genmask Flags MSS Window
>> irtt Iface
>> 192.168.0.0 * 255.255.255.0 U 0 0
>> 0 eth0
>> 192.168.254.0 * 255.255.255.0 U 0 0
>> 0 wlan0
>> link-local * 255.255.0.0 U 0 0
>> 0 eth0
>> loopback * 255.0.0.0 U 0 0
>> 0 lo
>> default 192.168.254.254 0.0.0.0 UG 0 0
>> 0 wlan0
>
> Any answers? I've read some stuff about this but haven't found
> anything.

Can you list ALL the IP addresses on BOTH networks and all the machines
that span both networks?


If network A can contact network B that implies routing must be working.
Since packets have to travel in both directions.

It looks more like a firewall issue to me

The Natural Philosopher wrote:
> mike3 wrote:
>> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
>>> Hi.
>>>
>>> I have the following network setup: 2 wired networks, plus a wireless
>>> connection between the two (it's too long to run cable). On one
>>> network, call it network #1, I have a Linux computer set up as
>>> arouter, and it contains a wireless and a wired network card. The other
>>> network, network #2, has a DSL modem which is used as both an Ethernet
>>> wired hub and as a wireless transmitter.
>>>
>>> But there's a problem: I can contact the computers on network #2 from
>>> #1, but not the other way around, although interestingly I can contact
>>> therouter'swired interface (address 192.168.0.254, which is on
>>> network #1). Why is that?
>>>
>>> The routing table on therouterlooks like this, if you need it:
>>> Destination Gateway Genmask Flags MSS Window
>>> irtt Iface
>>> 192.168.0.0 * 255.255.255.0 U 0 0
>>> 0 eth0
>>> 192.168.254.0 * 255.255.255.0 U 0 0
>>> 0 wlan0
>>> link-local * 255.255.0.0 U 0 0
>>> 0 eth0
>>> loopback * 255.0.0.0 U 0 0
>>> 0 lo
>>> default 192.168.254.254 0.0.0.0 UG 0 0
>>> 0 wlan0
>>
>> Any answers? I've read some stuff about this but haven't found
>> anything.
>
> Can you list ALL the IP addresses on BOTH networks and all the machines
> that span both networks?
>

At least mention how you configured the routing between the two
networks.

>
> If network A can contact network B that implies routing must be working.
> Since packets have to travel in both directions.

The OP used #1 and #2 as the names of his networks. It looks like your
network A is the OP's network #1 and your B is his #2. I'll stick to
the OP's naming scheme.

Assuming that all hosts on network #2 are using the DSL modem as
gateway, connectivity from network #1 to #2 implies:
either: there is a static network route configured to network #1 in the
DSL modem, pointing to the wireless interface of the linux
router,
or: such a route has been configured in every individual host on
network #2.

If the OP did set up such routes that would imply that he knows what
he is doing, and in that case he certainly would have mentioned those
routes (if he needed assistance from this news group at all).

My guess is that there are no routes defined from network #2 to #1.

>
> It looks more like a firewall issue to me
>

It looks to me that the connectivity from network #1 to #2 -lacking
network routes to network #1 on #2- can only be explained if the
linux router is using NAT while forwarding traffic from network #1
to #2. That would hide the whole #1 network for traffic originating
from #2, while still allowing traffic originating from network #1.
And that is exactly the OP's issue.


Regards,

Kees.

--
Kees Theunissen.

On Apr 28, 3:34 pm, The Natural Philosopher <a...@b.c> wrote:
> mike3 wrote:
> > On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
> >> Hi.
>
> >> I have the following network setup: 2 wired networks, plus a wireless
> >> connection between the two (it's too long to run cable). On one
> >> network, call it network #1, I have a Linux computer set up as arouter, and it contains a wireless and a wired network card. The other
> >> network, network #2, has a DSL modem which is used as both an Ethernet
> >> wired hub and as a wireless transmitter.
>
> >> But there's a problem: I can contact the computers on network #2 from
> >> #1, butnotthe other way around, although interestingly I can contact
> >> therouter'swired interface (address 192.168.0.254, which is on
> >> network #1). Why is that?
>
> >> The routing table on therouterlooks like this, if you need it:
> >> Destination Gateway Genmask Flags MSS Window
> >> irtt Iface
> >> 192.168.0.0 * 255.255.255.0 U 0 0
> >> 0 eth0
> >> 192.168.254.0 * 255.255.255.0 U 0 0
> >> 0 wlan0
> >> link-local * 255.255.0.0 U 0 0
> >> 0 eth0
> >> loopback * 255.0.0.0 U 0 0
> >> 0 lo
> >> default 192.168.254.254 0.0.0.0 UG 0 0
> >> 0 wlan0
>
> > Any answers? I've read some stuff about this but haven't found
> > anything.
>
> Can you list ALL the IP addresses on BOTH networks and all the machines
> that span both networks?
>
> If network A can contact network B that implies routing must be working.
> Since packets have to travel in both directions.
>
> It looks more like a firewall issue to me

I'll assume your "network A" is what I call "network #1" and
"network B" is what I call "network #2". Then, we have:

Network #1/A:
(all ethernetted into hub)
sgc1-karyo @ 192.168.0.1 (this is what I need to contact.)
sgc2 @ 192.168.0.2
iMac G5 machine @ 192.168.0.3 (I think)
sgc0-router @ 192.168.0.254 (ethernet side)

Network #2/B:
(ethernetted into DSL modem which has wireless capability)
sgc3-bigfootbox @ 192.168.254.1 (this is what I am trying to contact
from)
<a PowerMac G4 machine assigned a dynamic address by the DSL Modem>
sgc0-router (wireless side) @ 192.168.254.253
DSL modem's gateway to Internet @ 192.168.254.254

Also, I tried shutting off the firewalling on the router box
as an experiment to see if that was the issue and I still
couldn't contact...

On Apr 28, 5:24 pm, Kees Theunissen <theun...@rijnh.nl> wrote:
> The Natural Philosopher wrote:
> > mike3 wrote:
> >> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
> >>> Hi.
>
> >>> I have the following network setup: 2 wired networks, plus a wireless
> >>> connection between the two (it's too long to run cable). On one
> >>> network, call it network #1, I have a Linux computer set up as
> >>> arouter, and it contains a wireless and a wired network card. The other
> >>> network, network #2, has a DSL modem which is used as both an Ethernet
> >>> wired hub and as a wireless transmitter.
>
> >>> But there's a problem: I can contact the computers on network #2 from
> >>> #1, butnotthe other way around, although interestingly I can contact
> >>> therouter'swired interface (address 192.168.0.254, which is on
> >>> network #1). Why is that?
>
> >>> The routing table on therouterlooks like this, if you need it:
> >>> Destination Gateway Genmask Flags MSS Window
> >>> irtt Iface
> >>> 192.168.0.0 * 255.255.255.0 U 0 0
> >>> 0 eth0
> >>> 192.168.254.0 * 255.255.255.0 U 0 0
> >>> 0 wlan0
> >>> link-local * 255.255.0.0 U 0 0
> >>> 0 eth0
> >>> loopback * 255.0.0.0 U 0 0
> >>> 0 lo
> >>> default 192.168.254.254 0.0.0.0 UG 0 0
> >>> 0 wlan0
>
> >> Any answers? I've read some stuff about this but haven't found
> >> anything.
>
> > Can you list ALL the IP addresses on BOTH networks and all the machines
> > that span both networks?
>
> At least mention how you configured the routing between the two
> networks.
>

Initially I had just used the Yast tool that came with the SUSE Linux
distribution I have on the router box, and set up two routes with:

Destination: 192.168.254.0 (net 2)
Gateway: 0.0.0.0
Subnet Mask: 255.255.255.0
Device: wlan0

Destination: 192.168.0.0 (net 1)
Gateway: 0.0.0.0
Subnet Mask: 255.255.255.0
Device: eth0

I also enabled IP Forwarding and IP Masquerading.

Was able to go from net 1 to net 2 but not the other way arond.
So I decided to see what would happen if I got rid of that and
just used the "route" command to add routes instead of going
through Yast, with the same setup, and that didn't ork it either.

>
>
> > If network A can contact network B that implies routing must beworking.
> > Since packets have to travel in both directions.
>
> The OP used #1 and #2 as the names of his networks. It looks like your
> network A is the OP's network #1 and your B is his #2. I'll stick to
> the OP's naming scheme.
>
> Assuming that all hosts on network #2 are using the DSL modem as
> gateway, connectivity from network #1 to #2 implies:
> either: there is a static network route configured to network #1 in the
> DSL modem, pointing to the wireless interface of the linux
> router,
> or: such a route has been configured in every individual host on
> network #2.
>
> If the OP did set up such routes that would imply that he knows what
> he is doing, and in that case he certainly would have mentioned those
> routes (if he needed assistance from this news group at all).
>
> My guess is that there are no routes defined from network #2 to #1.
>
>
>
> > It looks more like a firewall issue to me
>
> It looks to me that the connectivity from network #1 to #2 -lacking
> network routes to network #1 on #2- can only be explained if the
> linux router is using NAT while forwarding traffic from network #1
> to #2. That would hide the whole #1 network for traffic originating
> from #2, while still allowing traffic originating from network #1.
> And that is exactly the OP's issue.
>

So what should I do to resolve this problem? Add routes in the
DSL Modem? Which may be a hangup since the DSL Modem
does not seem to have a routing table in it (yes I looked over the
"admin" settings in the thing.).

mike3 wrote:
> On Apr 28, 5:24 pm, Kees Theunissen <theun...@rijnh.nl> wrote:
>> The Natural Philosopher wrote:
>>> mike3 wrote:
>>>> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
>>>>> Hi.
>>>>> I have the following network setup: 2 wired networks, plus a wireless
>>>>> connection between the two (it's too long to run cable). On one
>>>>> network, call it network #1, I have a Linux computer set up as
>>>>> arouter, and it contains a wireless and a wired network card. The other
>>>>> network, network #2, has a DSL modem which is used as both an Ethernet
>>>>> wired hub and as a wireless transmitter.
>>>>> But there's a problem: I can contact the computers on network #2 from
>>>>> #1, butnotthe other way around, although interestingly I can contact
>>>>> therouter'swired interface (address 192.168.0.254, which is on
>>>>> network #1). Why is that?
>>>>> The routing table on therouterlooks like this, if you need it:
>>>>> Destination Gateway Genmask Flags MSS Window
>>>>> irtt Iface
>>>>> 192.168.0.0 * 255.255.255.0 U 0 0
>>>>> 0 eth0
>>>>> 192.168.254.0 * 255.255.255.0 U 0 0
>>>>> 0 wlan0
>>>>> link-local * 255.255.0.0 U 0 0
>>>>> 0 eth0
>>>>> loopback * 255.0.0.0 U 0 0
>>>>> 0 lo
>>>>> default 192.168.254.254 0.0.0.0 UG 0 0
>>>>> 0 wlan0
>>>> Any answers? I've read some stuff about this but haven't found
>>>> anything.
>>> Can you list ALL the IP addresses on BOTH networks and all the machines
>>> that span both networks?
>> At least mention how you configured the routing between the two
>> networks.
>>
>
> Initially I had just used the Yast tool that came with the SUSE Linux
> distribution I have on the router box, and set up two routes with:
>
> Destination: 192.168.254.0 (net 2)
> Gateway: 0.0.0.0
> Subnet Mask: 255.255.255.0
> Device: wlan0
>
> Destination: 192.168.0.0 (net 1)
> Gateway: 0.0.0.0
> Subnet Mask: 255.255.255.0
> Device: eth0
>
> I also enabled IP Forwarding and IP Masquerading.
>
> Was able to go from net 1 to net 2 but not the other way arond.
> So I decided to see what would happen if I got rid of that and
> just used the "route" command to add routes instead of going
> through Yast, with the same setup, and that didn't ork it either.
>
>>
>>> If network A can contact network B that implies routing must beworking.
>>> Since packets have to travel in both directions.
>> The OP used #1 and #2 as the names of his networks. It looks like your
>> network A is the OP's network #1 and your B is his #2. I'll stick to
>> the OP's naming scheme.
>>
>> Assuming that all hosts on network #2 are using the DSL modem as
>> gateway, connectivity from network #1 to #2 implies:
>> either: there is a static network route configured to network #1 in the
>> DSL modem, pointing to the wireless interface of the linux
>> router,
>> or: such a route has been configured in every individual host on
>> network #2.
>>
>> If the OP did set up such routes that would imply that he knows what
>> he is doing, and in that case he certainly would have mentioned those
>> routes (if he needed assistance from this news group at all).
>>
>> My guess is that there are no routes defined from network #2 to #1.
>>
>>
>>
>>> It looks more like a firewall issue to me
>> It looks to me that the connectivity from network #1 to #2 -lacking
>> network routes to network #1 on #2- can only be explained if the
>> linux router is using NAT while forwarding traffic from network #1
>> to #2. That would hide the whole #1 network for traffic originating
>> from #2, while still allowing traffic originating from network #1.
>> And that is exactly the OP's issue.
>>
>
> So what should I do to resolve this problem? Add routes in the
> DSL Modem? Which may be a hangup since the DSL Modem
> does not seem to have a routing table in it (yes I looked over the
> "admin" settings in the thing.).
>
>
Do not use NAT except where you connect to the Internet.

That is most likeley the problem.

NAT is designed as an outward only firewall, by default effectively.

mike3 wrote:
> On Apr 28, 3:34 pm, The Natural Philosopher <a...@b.c> wrote:
>> mike3 wrote:
>>> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
>>>> Hi.
>>>> I have the following network setup: 2 wired networks, plus a wireless
>>>> connection between the two (it's too long to run cable). On one
>>>> network, call it network #1, I have a Linux computer set up as arouter, and it contains a wireless and a wired network card. The other
>>>> network, network #2, has a DSL modem which is used as both an Ethernet
>>>> wired hub and as a wireless transmitter.
>>>> But there's a problem: I can contact the computers on network #2 from
>>>> #1, butnotthe other way around, although interestingly I can contact
>>>> therouter'swired interface (address 192.168.0.254, which is on
>>>> network #1). Why is that?
>>>> The routing table on therouterlooks like this, if you need it:
>>>> Destination Gateway Genmask Flags MSS Window
>>>> irtt Iface
>>>> 192.168.0.0 * 255.255.255.0 U 0 0
>>>> 0 eth0
>>>> 192.168.254.0 * 255.255.255.0 U 0 0
>>>> 0 wlan0
>>>> link-local * 255.255.0.0 U 0 0
>>>> 0 eth0
>>>> loopback * 255.0.0.0 U 0 0
>>>> 0 lo
>>>> default 192.168.254.254 0.0.0.0 UG 0 0
>>>> 0 wlan0
>>> Any answers? I've read some stuff about this but haven't found
>>> anything.
>> Can you list ALL the IP addresses on BOTH networks and all the machines
>> that span both networks?
>>
>> If network A can contact network B that implies routing must be working.
>> Since packets have to travel in both directions.
>>
>> It looks more like a firewall issue to me
>
> I'll assume your "network A" is what I call "network #1" and
> "network B" is what I call "network #2". Then, we have:
>
> Network #1/A:
> (all ethernetted into hub)
> sgc1-karyo @ 192.168.0.1 (this is what I need to contact.)
> sgc2 @ 192.168.0.2
> iMac G5 machine @ 192.168.0.3 (I think)
> sgc0-router @ 192.168.0.254 (ethernet side)
>
> Network #2/B:
> (ethernetted into DSL modem which has wireless capability)
> sgc3-bigfootbox @ 192.168.254.1 (this is what I am trying to contact
> from)
> <a PowerMac G4 machine assigned a dynamic address by the DSL Modem>
> sgc0-router (wireless side) @ 192.168.254.253
> DSL modem's gateway to Internet @ 192.168.254.254
>
> Also, I tried shutting off the firewalling on the router box
> as an experiment to see if that was the issue and I still
> couldn't contact...

Right. I THINK I understand. You have essentially a wireless/wired
router, built out of Linux, with the wired side in 192.168.0/24 ..and
the wireless side on 192.168.254.0/24, which just has one machine on it.
And a wireless connected modem?

The wired side can talk to the wireless side, - which is just a G4 mac?
And a modem? but the wireless side can't talk to the wired side yes?

Both presumably can talk to the internet..?

What does the route command show?

However if response packets can come back from the G4 to the wired side,
routing would seem to be working: Asymmetrical access is symptomatic of
firewalling, of some sort, not routing, problems.

Do pings work in both directions or not?

mike3 wrote:
> On Apr 28, 5:24 pm, Kees Theunissen <theun...@rijnh.nl> wrote:
>> The Natural Philosopher wrote:
>>> mike3 wrote:
>>>> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
>>>>> Hi.
>>>>> I have the following network setup: 2 wired networks, plus a wireless
>>>>> connection between the two (it's too long to run cable). On one
>>>>> network, call it network #1, I have a Linux computer set up as
>>>>> arouter, and it contains a wireless and a wired network card. The other
>>>>> network, network #2, has a DSL modem which is used as both an Ethernet
>>>>> wired hub and as a wireless transmitter.
>>>>> But there's a problem: I can contact the computers on network #2 from
>>>>> #1, butnotthe other way around, although interestingly I can contact
>>>>> therouter'swired interface (address 192.168.0.254, which is on
>>>>> network #1). Why is that?
>>>>> The routing table on therouterlooks like this, if you need it:
>>>>> Destination Gateway Genmask Flags MSS Window
>>>>> irtt Iface
>>>>> 192.168.0.0 * 255.255.255.0 U 0 0
>>>>> 0 eth0
>>>>> 192.168.254.0 * 255.255.255.0 U 0 0
>>>>> 0 wlan0
>>>>> link-local * 255.255.0.0 U 0 0
>>>>> 0 eth0
>>>>> loopback * 255.0.0.0 U 0 0
>>>>> 0 lo
>>>>> default 192.168.254.254 0.0.0.0 UG 0 0
>>>>> 0 wlan0
>>>> Any answers? I've read some stuff about this but haven't found
>>>> anything.
>>> Can you list ALL the IP addresses on BOTH networks and all the machines
>>> that span both networks?
>> At least mention how you configured the routing between the two
>> networks.
>>
>
> Initially I had just used the Yast tool that came with the SUSE Linux
> distribution I have on the router box, and set up two routes with:
>
> Destination: 192.168.254.0 (net 2)
> Gateway: 0.0.0.0
> Subnet Mask: 255.255.255.0
> Device: wlan0
>
> Destination: 192.168.0.0 (net 1)
> Gateway: 0.0.0.0
> Subnet Mask: 255.255.255.0
> Device: eth0
>
> I also enabled IP Forwarding and IP Masquerading.
>
> Was able to go from net 1 to net 2 but not the other way arond.
> So I decided to see what would happen if I got rid of that and
> just used the "route" command to add routes instead of going
> through Yast, with the same setup, and that didn't ork it either.

Your main problem is that you're using two separate networks
with different address ranges. This requires a more advanced router
than your DSL modem. You need to define an extra network route on
the DSL modem, and you wrote that you can't do that on this modem.

The way you configured the linux router -with IP Forwarding and
IP Masquerading enabled- is per definition a one-way solution.
Masquerading (a.k.a. Network Address Translation or NAT) hides
your network #1. All IP addresses in packages forwarded by the
linux router will be 'translated' to the IP address of the wlan0
interface. Your DSL modem uses the same technique to hide
your internal network behind your single public IP number.

Instead of using two different address ranges I would set
up networks #1 and #2 to use the same 192.168.254.x address
range. Configure your linux system as a bridge (_not_ a router)
to connect the two network sections together. That will change
your separated network sections into a single 'logical' network.

See http://www.linux-foundation.org/en/Net:Bridge for more
information about configuring a bridge.


Regards,

Kees

--
Kees Theunissen.

On Apr 29, 2:08 pm, Kees Theunissen <theun...@rijnh.nl> wrote:
> mike3 wrote:
> > On Apr 28, 5:24 pm, Kees Theunissen <theun...@rijnh.nl> wrote:
> >> The Natural Philosopher wrote:
> >>> mike3 wrote:
> >>>> On Apr 26, 6:27 pm, mike3 <mike4...@yahoo.com> wrote:
> >>>>> Hi.
> >>>>> I have the following network setup: 2 wired networks, plus a wireless
> >>>>> connection between the two (it's too long to run cable). On one
> >>>>> network, call it network #1, I have a Linux computer set up as
> >>>>> arouter, and it contains a wireless and a wired network card. The other
> >>>>> network, network #2, has a DSL modem which is used as both an Ethernet
> >>>>> wired hub and as a wireless transmitter.
> >>>>> But there's a problem: I can contact the computers on network #2 from
> >>>>> #1, butnotthe other way around, although interestingly I can contact
> >>>>> therouter'swired interface (address 192.168.0.254, which is on
> >>>>> network #1). Why is that?
> >>>>> The routing table on therouterlooks like this, if you need it:
> >>>>> Destination Gateway Genmask Flags MSS Window
> >>>>> irtt Iface
> >>>>> 192.168.0.0 * 255.255.255.0 U 0 0
> >>>>> 0 eth0
> >>>>> 192.168.254.0 * 255.255.255.0 U 0 0
> >>>>> 0 wlan0
> >>>>> link-local * 255.255.0.0 U 0 0
> >>>>> 0 eth0
> >>>>> loopback * 255.0.0.0 U 0 0
> >>>>> 0 lo
> >>>>> default 192.168.254.254 0.0.0.0 UG 0 0
> >>>>> 0 wlan0
> >>>> Any answers? I've read some stuff about this but haven't found
> >>>> anything.
> >>> Can you list ALL the IP addresses on BOTH networks and all the machines
> >>> that span both networks?
> >> At least mention how you configured the routing between the two
> >> networks.
>
> > Initially I had just used the Yast tool that came with the SUSE Linux
> > distribution I have on the router box, and set up two routes with:
>
> > Destination: 192.168.254.0 (net 2)
> > Gateway: 0.0.0.0
> > Subnet Mask: 255.255.255.0
> > Device: wlan0
>
> > Destination: 192.168.0.0 (net 1)
> > Gateway: 0.0.0.0
> > Subnet Mask: 255.255.255.0
> > Device: eth0
>
> > I also enabled IP Forwarding and IP Masquerading.
>
> > Was able to go from net 1 to net 2 but not the other way arond.
> > So I decided to see what would happen if I got rid of that and
> > just used the "route" command to add routes instead of going
> > through Yast, with the same setup, and that didn't ork it either.
>
> Your main problem is that you're using two separate networks
> with different address ranges. This requires a more advanced router
> than your DSL modem. You need to define an extra network route on
> the DSL modem, and you wrote that you can't do that on this modem.
>

Oh, so simply being able to connect and talk to the Linux machine
wirelessly is not enough -- the DSL modem *must* play a part in the
actual routing process beyond that, and it is incapable of doing so.

I guess what I'm having a little trouble with is that I _can_ connect
to the Linux machine from the 2nd network (the 254 range), so why
can't the computers there just head right on through it? What does the
DSL modem need to do to allow them to head _through_ this machine? I
guess that although the modem "feels" like a network hub or switch
with an added "wireless jack", it is not one, it is something worse.

However, I just noted a 3rd possiblity here. I THINK we have on hand a
"Cisco DSL Router" or something like that, but we have not used it. It
looks like it may be more powerful, perhaps I should give it a try?

> The way you configured the linux router -with IP Forwarding and
> IP Masquerading enabled- is per definition a one-way solution.
> Masquerading (a.k.a. Network Address Translation or NAT) hides
> your network #1. All IP addresses in packages forwarded by the
> linux router will be 'translated' to the IP address of the wlan0
> interface. Your DSL modem uses the same technique to hide
> your internal network behind your single public IP number.
>

But is there another way to configure it that would make it two-way?

> Instead of using two different address ranges I would set
> up networks #1 and #2 to use the same 192.168.254.x address
> range. Configure your linux system as a bridge (_not_ a router)
> to connect the two network sections together. That will change
> your separated network sections into a single 'logical' network.
>
> Seehttp://www.linux-foundation.org/en/Net:Bridgefor more
> information about configuring a bridge.
>

I suppose I could try this as well, however I prefer the partitioned
setup as I'd like to keep these networks distinct.