From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mateusz Viste Subject: Re: DOSemu networking made easy Date: Mon, 24 Jun 2013 15:50:44 +0200 Message-ID: <51C84EB4.3070000@viste-family.net> References: <51C82F2C.5@viste-family.net> <51C84847.60903@list.ru> Mime-Version: 1.0 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <51C84847.60903@list.ru> Sender: linux-msdos-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="utf-8"; format="flowed" To: linux-msdos@vger.kernel.org Hi Stas! No, it's not naive at all :). And my descriptions are probably lacking = a=20 fair amount of clarity. > actually solve? I can see some advantage of this over > the bridging tap0 with eth0 solution, Bridging tap0 with eth0 requires that: - there is a DHCP server somewhere in the network - you are actually using always eth0 (and not wlan0 for instance when= =20 on the road, and eth0 when at home, etc) - you need to have the right to use more than 1 IP All the conditions above are often unrealistic on a laptop, moving from= =20 home/office/hotel on the road, etc. > but what advantage > does it give over the static route with masquerading solution? Technically - very little. BUT: - it's probably much easier to use taprouter - you don't need to play with NAT on your own PC - you don't need to enable ipforward=3D1 on your PC (which I am usual= ly=20 relunctant to do when being on a foreign network) > You seem to be saying that the dosemu's networking > configuration tends to change when you relocate your > laptop - I can agree with this if we talk about bridging, > but is it still true for the routing case? No, it is not indeed. The only differences are points above. basically taprouter makes it possible to use DOSemu with networking=20 without reconfiguring your host PC to act as a router with NAT &=20 possibly DHCP. Plus, taprouter works in usermode (no need to play with=20 commands that look obscure to many people using the root account). in fact, taprouter provides exactly the same service than most=20 hypervisors do nowadays (like virtualbox, qemu, bochs..). ie. a 'net=20 user' networking mode, where the user don't have to care about=20 networking configuration, because as long as his host PC have internet=20 access, the virtual machine (or DOSemu in this case) will, too. > I think I can just install a generic DHCP server and dosemu > will be able to reach it. Sure. You are also one step away from spoofing any possible DHCP server= s=20 on whatever network you connect to, if you don't take extra care about=20 how you configure your DHCP server. ;) The solutions you describe are perfectly valid, but they are targeted t= o=20 people that know exactly what they are doing, and why (and able to adap= t=20 the configuration when needed). taprouter is targetted to people that don't have in-depth networking=20 knowledge, and just want 'internet to work in DOSemu', or simply don't=20 have time to wonder if their DOSemu setup will brake whenever they move= =20 from one network to another. > Also, if tap0 is bridged with eth0, > dosemu will be able to reach an outer DHCP server. > Is this not true? Totally true. But again, it applies to the situation when there is a=20 DHCP server out there, AND you are allowed to use more than 1 IP addres= s=20 at a time. > I am not sure what does this mean: > --- > taprouter expects you to use the IP address 10.0.2.1 as a default ga= teway > --- > you mean default gateway for dosemu or what? Yes, that's exactly what I meant. From the point of view of DOSemu,=20 DOSemu thinks it's in a 10.0.2.0/24 LAN with a single gateway, and a=20 single DNS server - and these won't change, no matter how the 'real'=20 network situation of the host looks like. > Why your tool itself need a tap device? because it acts like a tap client. You'd have to imagine that the bridg= e=20 is a L2 switch, and tap interfaces are RJ45 sockets :). You connect bot= h=20 your DOSemu and the router to the switch, so they can speak to each=20 other. I think this needs to be explained with a drawing - a will do=20 such schema and post it on my website. > Never used dosemu with DHCP, but I haven't expected there > are any problems that need an extra tool to solve. Because in fact, technically there is no need - you can just as well=20 obtain the same result with pure bridging or tap routing + masquerading= ,=20 with optionally a DHCP server running on your PC, and maybe a DNS relay= =2E=20 But it's far from being trivial to set up, and additionally you have to= =20 keep in mind that you need to adapt the whole thing when your network=20 settings change, and make sure that nobody can use your machine now as = a=20 DNS server and/or anonymous router and/or DHCP server. I hope it's a bit clearer now :) Let me know. cheers, Mateusz On 06/24/2013 03:23 PM, Stas Sergeev wrote: > 24.06.2013 15:36, Mateusz Viste =D0=BF=D0=B8=D1=88=D0=B5=D1=82: >> Hi all, >> >> I'm happily using DOSemu since a long time now, and the one thing th= at >> has always been bothering me is the complicated networking settings. >> Playing with bridging and masquerading and transforming the host int= o >> a routing machine is usually fine on a home desktop PC, but it becom= es >> a real pain on a laptop which, by nature, often change it's network >> settings and physical locations. >> >> This is why I wrote a tool to make DOSemu networking much easier (at >> least from my POV): taprouter. > Hi! > > Maybe a naive question, but, what problem does it > actually solve? I can see some advantage of this over > the bridging tap0 with eth0 solution, but what advantage > does it give over the static route with masquerading solution? > > You seem to be saying that the dosemu's networking > configuration tends to change when you relocate your > laptop - I can agree with this if we talk about bridging, > but is it still true for the routing case? > > I think I can just install a generic DHCP server and dosemu > will be able to reach it. Also, if tap0 is bridged with eth0, > dosemu will be able to reach an outer DHCP server. > Is this not true? > > I am not sure what does this mean: > --- > taprouter expects you to use the IP address 10.0.2.1 as a default gat= eway > --- > you mean default gateway for dosemu or what? > > Why your tool itself need a tap device? > > Sorry, I am just a bit lost. :) > Never used dosemu with DHCP, but I haven't expected there > are any problems that need an extra tool to solve. > -- To unsubscribe from this list: send the line "unsubscribe linux-msdos" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html