<div dir="ltr"><br><br><div class="gmail_quote">On Mon, Sep 15, 2008 at 11:51 AM, Kevin Fries <span dir="ltr"><<a href="mailto:kfries@cctus.com">kfries@cctus.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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________________________________________<br>
From: <a href="mailto:ubuntu-us-co-bounces@lists.ubuntu.com">ubuntu-us-co-bounces@lists.ubuntu.com</a> [<a href="mailto:ubuntu-us-co-bounces@lists.ubuntu.com">ubuntu-us-co-bounces@lists.ubuntu.com</a>] On Behalf Of Jim Hutchinson [<a href="mailto:jim@ubuntu-rocks.org">jim@ubuntu-rocks.org</a>]<br>
</div>Sent: Sunday, September 14, 2008 10:44 PM<br>
To: Ubuntu Colorado Local Community Team<br>
<div class="Ih2E3d">Subject: Re: [CoLoCo] changing subnet mask<br>
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</div><div class="Ih2E3d">On Wed, Sep 10, 2008 at 9:29 AM, Kevin Fries <<a href="mailto:kfries@cctus.com">kfries@cctus.com</a><mailto:<a href="mailto:kfries@cctus.com">kfries@cctus.com</a>>> wrote:<br>
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> Well, what I wanted was two routers with DIFFERENT ssid and channel and different subnets. Basically,<br>
> I was trying to create two separate networks that were not isolated on the LAN side. I wanted to be able<br>
> to ssh between them and use one computer to manage both routers. When my desktop is connected to<br>
> the "1" subnet, it cannot see the router or computers on the "2" subnet. I was trying to figure out if a<br>
> different subnet mask would allow this to work.<br>
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</div>This was part of my reason for asking what you were trying to do. Your original posting indicated that you were trying to get around a computability issue. The ONLY reason to segment the network is for security purposes (in a business, accounting departments are often on a separate network to secure financial records). If all you were trying to do was get around the broadcomm compatibility issue and wanted machines to be visible across both routers, you wanted one network. Two networks with routing rules are more trouble than they are worth for a home network, unless you are using it as a home learning exercise. Even then, there are more effective ways to learn.<br>
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So, now I am back to being confused as to what you are trying to do... or maybe I should say, what and why you are trying to implement it with two networks.</blockquote><div><br>My specific and original goal was to accommodate laptops in the home that don't seem to want to connect to the linksys (router 1) running dd-wrt. To that end I added the dlink (router 2). Turning off the dhcp on the dlink and putting it on the same network solved my initial issue which was caused by using different subnets and thus an inability to manage the whole network(s). However, the other night and for whatever reason, computers would not connect to the dlink and I wondered if it had anything to do with dhcp being served by the linksys. As a test I put the dlink back on it's own subnet and turned on dhcp and for whatever reason computer would connect again. Clearly there are issues with my network, but I think all of them are related to using non-factory firmware (which I'm doing because it's fun) and wifi nics that are not well supported in Linux (which I can't control). Fwiw, a macbook will connect at all times to any router regardless of how it's set up so that points the finger more towards Linux broadcom drivers.<br>
<br>Now, becuase I like to play and experiment with things my specific goal got confused with experimental goals - in this case the goal of understanding subnets. I tend to play with things breaking and fixing them as a way to learn. I can break this easily enough :) and I have a hunch that subnet masks would be a possible tool for fixing so that is what I've been investigating.<br>
<br>To be clear, I know how to make this all work on one network (aside from the possible broadcom issues). What I didn't know was how to make 2 networks act like one regardless of whether or not one should.<br> <br></div>
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> I think that is right but not sure what the "fixed at .1 or .254" or ".3 or .252" lines mean. I have one<br>
</div>> router with a default gateway of <a href="http://192.168.1.1" target="_blank">192.168.1.1</a><<a href="http://192.168.1.1" target="_blank">http://192.168.1.1</a>> and the other with<br>
> <a href="http://192.168.2.1" target="_blank">192.168.2.1</a><<a href="http://192.168.2.1" target="_blank">http://192.168.2.1</a>>. Both are serving DHCP and the .2 router is connected from a lan port<br>
<div class="Ih2E3d">> of the .1 into the WAN port of the .2. The ssids are different though. This is working except I can't access<br>
> computers on the .2 subnet or the router from computers on the .1 network. That is what I'm trying to fix.<br>
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</div>Fixed at .1 or .255 means, do not allow that interface to obtain an IP address from DHCP, but instead make it a fixed IP address. If your network is <a href="http://192.168.1.0" target="_blank">192.168.1.0</a>, then fixed at .1 means set a static IP address for the interface at <a href="http://192.168.1.1" target="_blank">192.168.1.1</a>. Gateways are generally either the first or last address in the range depending on the network admin. When I am fixing addresses, I always set static servers in the 1-49 range, and routers in the 240-254 range. (For the records, 200-239 is for printers and other misc equipment, 100-199 is for desktops, and 50-99 are for mobile devices such as laptops, but that is my anal retentive system, use whatever numbering scheme works for you).</blockquote>
<div><br>Okay, thanks. I get that now.<br> <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>
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> This only works upstream (i.e. from computers on the .2 network to computers on the .1) but not vice versa. I can only ssh one way.<br>
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</div>This is why you want one network. Think of this like one of those diagrams they showed you in math class where you have a circle labeled A, and a second circle completely contained inside the first circle labeled B. Since B is completely inside A, anything in B is also in A (any machine in network 2 can see all the machines in network 1). Everything outside of A is neither in A or B (any machine from outside of network 1 is foreign to both network 1 and network 2). Everything else is local to A, but not included in B (any machine in network 1 can not see those in network 2 because the machine has no way of knowing that network 2 is inside network 1). By making it one network, you overlay the circles, so that everything in A is also in B (Network 1 and network 2 are the same space, so all machines should be visible. I hope equating it to a vein diagram helps.</blockquote>
<div><br>I understand (and understood) this. I was just wanting to break the rules and see if I could.<br> <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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You can also try, though I have never seen this work in a wireless network, setting your desktop's netmask to /22 (<a href="http://255.255.252.0" target="_blank">255.255.252.0</a>). </blockquote><div><br>Bingo. That was the magic bit I was looking for in the beginning. I wanted to change the subnet mask and see what would happen but didn't know the funky math needed to do it. I still don't know the math but now I have a mask I can try (and probably promptly break more stuff - thank god for the reset button). What I don't know is what all has to have the subnet changed - the one router, both, both and the laptops, etc. I guess I'll find out.<br>
<br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Again, this is one of those areas where theory meets actuality in a ugly game of "but why won't this work, it should". The problem is that most of these wireless routers are designed to operate in one of two modes: either as a access point, where it expects that there is a bigger domain managed by a set of servers in the back; or as a central gateway where it expects to be king of the network. You are trying to add a third scenario, where it is king of its network, but also aware of a second network in parallel. Larger routers (i.e. Cisco or Linux routers) are built for this by only defining generic interfaces, which then allows a professional administrator to define a complex set of rules to handle all routes. The home routers you are dealing with are dumbed down for non-administrators to use from home. Complex routing is generally the first thing to be eliminated.</blockquote>
<div><br>Ah, but one of the fun things with dd-wrt is that it adds back some of that complexity and gives you quite a bit to play with.<br> <br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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Hope I got you closer this time<br>
<div><div></div><div class="Wj3C7c"></div></div></blockquote><div><br>Yep. Spot on. Thanks. I'll let you know if I mange to make things work they way I want even if it's not what I should be doing. I was never one to follow rules.<br>
</div></div><br>-- <br>Jim (Ubuntu geek extraordinaire)<br>----<br>Please avoid sending me Word or PowerPoint attachments.<br>See <a href="http://www.gnu.org/philosophy/no-word-attachments.html">http://www.gnu.org/philosophy/no-word-attachments.html</a><br>
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