Author Topic: Dedicated networking  (Read 3198 times)

LameDuck

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Dedicated networking
« on: December 15, 2008, 06:11:13 pm »
I'll probably be flamed for this, but I'm only offering my opinion in an attempt to contribute.

I don't like the core expecting to be the DHCP server and the gateway for the network, it's not the way most people use modern networks.  Most people (and by people I mean the average man inthe street, not kernel hackers), have a wireless modem router, typically supplied by their ISP, a laptop that is configured by plugging in the ISP cdrom.  I think it's too much to expect them to have a dual Nic'd machine and have them configure a router to switch off dhcp.  Wireless is wide spread now, because people don't want wires.  I use it personally because I live in a rented flat and I can't drill holes in the wall and don't want 20 meter cat5 tripping me up on my way to the bathroom!

I understand the reason for doing it and like the idea of netbooting thin (and potentially cheap) clients.  A clever solution to a tricky problem, I like it.

Why not have alternative solutions, like a distributed architecture, in addition.  So that those of us who want, can have something different. 

Just a thought.

Ok, light those pilots and make me cornflake ;-)

krys

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Re: Dedicated networking
« Reply #1 on: December 15, 2008, 06:23:19 pm »
I would personally recommend that you edit this post before its too late... I have seen a number of people complain about the core being the DHCP and it never ends well.

LameDuck

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Re: Dedicated networking
« Reply #2 on: December 15, 2008, 06:30:36 pm »
I think it's a great idea as far as it goes, but the number of complaint about it demonstrate that it's an issue for many users.  I'm not sure why it is the dhcp server, because IIRC, the image server does not need to be on the same IP as the DCHP server, it just needs to be on the the same subnet.

Personally speaking, I'd leave it as it is for the main, but I'd like to have an option to change it at install time.  Hey, I'm very old and opinionated, therefore used to being flamed  ;)

freymann

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Re: Dedicated networking
« Reply #3 on: December 15, 2008, 06:46:18 pm »
I think it's a great idea as far as it goes, but the number of complaint about it demonstrate that it's an issue for many users.  I'm not sure why it is the dhcp server, because IIRC, the image server does not need to be on the same IP as the DCHP server, it just needs to be on the the same subnet.

Um, well, let me see... since LinuxMCE is much more than just a "media center" and offers Plug 'n Play and Home Automation control, the requirements to use it are a little bit different than most other plain 'ole Media Centers.

If you read the answers to those posts that complained about this, you would have read why this is necessary. I don't think too many experienced users in the forums will even bother to respond to your post since this has been hashed about many times and is well documented as to the how's and why's.

As for wireless, you can't netboot a wireless media director (well, it *can* be done but you're wasting your time) so you've already cut off one major benefit of LMCE. At best you could set up a core but that'll give you only one media station, and if you set up with one network card then you've already invited trouble.

As I've learned (the hard way) if you don't follow the suggested setup and configuration you're not going to have a very good experience with LMCE. Don't blame the crew or the software, the requirements are laid out and are very clear. Follow them and you will most likely enjoy LMCE. Ignore them and you'll pay the price.

I do agree that some people cannot make use of LinuxMCE because they don't want to or can't follow the proper network configuration, for the reasons you've cited. I would have to say to that group that LMCE isn't for you then... go use MythBuntu, XBMC, or some of those awful windoze based Media Centers.

krys

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Re: Dedicated networking
« Reply #4 on: December 15, 2008, 07:08:06 pm »
Personally speaking, I'd leave it as it is for the main, but I'd like to have an option to change it at install time.  Hey, I'm very old and opinionated, therefore used to being flamed  ;)

sounds like you are someone who wants to be flamed, also know as a troll.

tschak909

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Re: Dedicated networking
« Reply #5 on: December 16, 2008, 01:05:31 am »
I'm one of the devs,

and believe me, if there was a way we could keep all the features, and keep them plug and play as they are now, and not be the center of the home network... we would do it.

There is no clean way to do this, and yes..stuff has been tried... it gets rather nasty.

-Thom

sp00nhead

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Re: Dedicated networking
« Reply #6 on: December 16, 2008, 12:26:22 pm »
Ok so we all know the reasons why is has to be the server, netboot pxe hooks and the auto detect etc.

FYI I'm just thinking aloud here, if its already been shot down then so be it.

Now i used to play around with arp monitoring and detecting machines being added/removed from a network using the arp tables on the switches/routers. If we could get this linked into firing off the network plug and play scripts that would remove the need for the dhcp being on the core. We'd still need the bootp being setup to point to the CORE, which most home routers/modems will not allow you to do.
One idea could be to have a usb boot image that gets the local network up and then uses a broadcast address to find the core and carry on the boot process via net mounts. This would allow us to support wireless devices on boot.
This would need alot of looking at to make it just work and get to the current place we are with teh CORE being teh router and HUB. but in my mind i can see it working.
Step one > Getting arp detection working on a single network core << i'm halfway there with my msi media single card core
Step two > Patch the network scanning for arp use

Step three > Looks at needed mini boot env for wireless systems

Not sure if its do able at all and will take a long time to get close to current system but hey thats the wounder of FOSS development, people can take tangents and explorer other options. Will also help me understand the system abit more, which can't be a bad thing.

Well that my view on the whole thing. and i've not even started to talk about vlans :)

tschak909

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Re: Dedicated networking
« Reply #7 on: December 16, 2008, 01:13:44 pm »
Hari did this very thing.

-Thom

los93sol

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Re: Dedicated networking
« Reply #8 on: December 16, 2008, 02:09:00 pm »
Good stuff going on here, I'd love to offload the DHCP server from my CORE, but for the time being I am using VLANS to solve my issue.  The problem for me was that I cannot physically place my core where it needs to be in my network (well...I could but it would make development very difficult).  My solution was to create a VLAN so my connection is setup as follows:

Internet<>Switch #1 VLAN 1<>Switch #2 VLAN 1<>CORE<>Switch #2 VLAN 2

In this way I've simulated the core being where it needs to be on my network and all LMCE connected devices run on VLAN 2.  I can easily switch ports over as needed and my switches support WVLAN's as well so no trouble there.  So far I haven't found any issues with this method, but I'm sure a networking guru could poke a few holes in it. :)

hari

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Re: Dedicated networking
« Reply #9 on: December 16, 2008, 02:19:10 pm »
the arp detection works pretty fine. The problem is that there is no unified way to configure that random "foreign" dhcp server. I was playing a bit with IOS, this is all achievable. But as TSCHAK said, there is no _uniform_ way to do it for every dhcp server, out of the box and without special config.

I for my part did not follow the arpwatch approach any further, why not use the luxury from lmce :-) For other people with special networking requirements: use a dedicated VLAN for LMCE and be happy without hazzles.

But if somebody comes up with a brilliant idea, why not. It is just that until now all approaches were flawed in one way or the other.
 
br, Hari
rock your home - http://www.agocontrol.com home automation

sp00nhead

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Re: Dedicated networking
« Reply #10 on: December 16, 2008, 03:06:37 pm »
it good to see others has looked at this before.
The only problem with VLANs is the lack of support on consumer routers.

I'll setup a vmware network tonight and see what i can do via arpwatch, with a bit of arp poisoning might bea ble to do re-writes on the fly to direct all requests to the core.

But really why bother :) two lan card are the way

hari

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Re: Dedicated networking
« Reply #11 on: December 16, 2008, 05:41:45 pm »
this was the original thread: http://forum.linuxmce.org/index.php?topic=2817.0

br, Hari
rock your home - http://www.agocontrol.com home automation

los93sol

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Re: Dedicated networking
« Reply #12 on: December 16, 2008, 05:54:15 pm »
Actually, dd-wrt makes VLANS possible and simple to use/configure for literally hundreds of off-the-shelf routers.  I think the real problem is that your average Joe can barely get his/her head around basic networking nevertheless flashing a custom firmware and understanding VLANS.  I'm interested to see how you get on as the issue of needing the core to have a specific physical location in the network was an initial stumbling block for me and I'm sure others since I don't have a surplus of machines laying around to just start dabbling.

sp00nhead

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Re: Dedicated networking
« Reply #13 on: December 16, 2008, 07:02:01 pm »
Thanks for the pointer hari, i'll use that as a base to start from.

If we're offering just a single node hybrid mode (a lot of these people testing the water are only interested in this) then we don't even need to touch the existing dhcp server on the routers. And if i go down the road of USB based boot image then no need top offer bootp/PXE server, so the dhcp server isn't needed. We can just update the stored ip addresses for any network device as and when they change on the network.

LameDuck

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Re: Dedicated networking
« Reply #14 on: December 18, 2008, 07:17:18 pm »
Ok, so clearly LMCE is not going to be for me, but hats off to a good effort.  LMCE is main stream now, a lot of ordinary people are talking about it and that's one heck of an achievement in the Linux Open Source arena, puts you right up there with Apache and the like.  Very impressive.

One last cheeky question ;).   Some alternatives were suggested.  Xmbc doesn't appear to handle TV, so that's a non starter.  Unless MythTv has got a lot less flakey, I won't be trying that!  I have to work with windows, so hate having it at home.  I did however come across FreeVo, which has multiple backends and front ends on one network, which is exactly what "I" am looking for.  Has anyone tried that?  I figure you guys will tell me it's bad points, but their forum may be slightly biased towards it ;-)