Changing CORE IP#?

[Matthew]

When I installed LMCE, I accepted its offer to run a DHCP server, even though my LAN already has one running, and the LMCE PC has only one ethernet port, which is connected to that LAN. Now I can't ping between the LMCE host and other hosts on the LAN. Or to the router on the LAN (so, eg. (apt-get update) fails to connect).

How can I make the LMCE PC use the LAN DHCP? Is its IP# stored anywhere but in its own DHCP config (and its DHCP client's cache, which seems to be pointing at its own DHCPd)? If I just remove the DHCPd startup from the Kubuntu startup scripts, can I just expect the LMCE to start up, use its DHCP client to get an address from my existing LAN DHCPd, and count on the IP# to propagate throughout LMCE properly?

I'd prefer to use an LMCE UI to fix this, but I'll use the Kubuntu desktop (and its commandline shell) without reservation if that's the only way.

[tschak909]

I recommend using LMCE's DHCP server, otherwise you will lose a great deal of plug and play functionality. With that said, the Web Admin gives you the ability to turn on and off the DHCP server.

-Thom

[teedge77]

how'd i know someone was gonna say that? 

[tschak909]

i'm tellin ya... i'm gonna make a set of macros for us with canned responses. I'm getting slightly tired of people asking the same questions over and over without at least...seeing...oh...if they've been asked before...

-Thom

[Zaerc]

i'm tellin ya... i'm gonna make a set of macros for us with canned responses. I'm getting slightly tired of people asking the same questions over and over without at least...seeing...oh...if they've been asked before...

-Thom

That's more or less how I use the wiki, easier to paste an url then to repeat the same things over and over again.

Next I'm willing to bet Matthew is going to comment how he just wants a media center without the other features...

[Matthew]

I did search the forums for "dhcp", but I got a long list of results to comb through, with very few matching my config (single NIC, version 0704). The one thread that specifically addressed my actual question included some flat assertions that changing the /etc/network/interfaces value was the simple answer, with no complex intermediary dependencies distributed throughout the rest of LMCE, and then some contradictions with evidence of that. As well as some confused anwsers, including some from you, Zaerc. But not a conclusive answer of whether changing the IP# in its OS-authoritave location would create inconsistencies among other LMCE dependencies not updating properly.

And I couldn't find any other clear answer to why the LMCE has to be the DHCP server for my network. Or any discussion of why its DHCPd would set up a subnet that can't connect to my router, when there's an existing DHCPd running on that router.

Maybe this question is indeed asked quite a lot. That's what a FAQ is for. Such a FAQ is a lot more helpful than insulting responses that the question is asked a lot, without offering a useful answer. Which in turn makes this problem look even more like a bug, really a design flaw, since a single NIC LMCE on an existing network seem the most common setup for an installer to expect, especially with the project in its current state (ie. attracting a lot of people trying it out before committing to using it).

But the bottom line is that even after I did search the forums, the people who did respond to this question didn't give me any info to help solve my problem - and therefore the problem of probably others who will find my question when they do their search.

So I'll ask again: given my predictable, automatically installed IP config on my LAN with my existing DHCP server, how can I assign LMCE an IP# on the existing LAN segment so it can route to the Internet, and without disconnecting other LMCE services which will still look for the original IP#? Can I just edit /etc/network/interfaces ? Should I edit LMCE's DHCPd configs? Must I disable my existing DHCPd, and let my whole LAN get its IP#s from LMCE (rebooting every LAN host)? Or is there another best way to handle this common problem?

[Zaerc]

The best way is to use 2 network cards and put the LMCE core (or hybrid) in between the internet and the rest of your network and let the lmce core do the DHCP on the internal network. http://wiki.linuxmce.org/index.php/Why_dual_network_cards%3F

Is that the answer you were looking for?  Because I can't make heads or tails out of your question (both times), beyond that it seems to have something to do with DHCP and a single NIC setup.   Try reading: http://www.catb.org/~esr/faqs/smart-questions.html maybe that helps a bit.

Also feel free to update the FAQ, it is in the WIKI after all, but aparently nobody that "suffered" from this horrendous problem seemed to care enough to bother. 

Now if you'll excuse me, I have other things to do besides answering the same question over and over and over again, just because some people who can't figure things out for themselves don't feel like using the recommended setup.  And just to get things straight, your self inflicted problem is not my responsability.

Is there anything else you'd like to lecture us on?

[1audio]

Matthew:
Zaerc can get a little cranky when its this far past his bedtime. And he is doing very useful stuff with the DC ripping system. However I have answered this question many times myself for installations very like yours. Here goes again.
If all you want to try is a stand alone box then disable the internal DHCP server and make sure the external IP is set to DHCP in advanced-network-network settings. and turn off the firewall so you can access it from the network. Don't change anything elsewhere or you may never recover. The scripts drive everything.
You can play with it to your hearts content then. But to get the value and utility you will need to set it up in a more standard mode- single NIC: disable the DHCP on your router, set a fixed IP for the box in the router's range, turn on DHCP and you may as well use the default IP range. Restart or reset the network on any other device you have in your network so they get new IP addresses from the LMCE box. I currently have 30 devices on my network and no problems managing them.
I use network magic on my PC's and it lets me see the devices and their mac addresses, which is a great diagnostic tool.
If I can figure out the WiKi editing I'll give it a try again. (The last few times I couldn't find a way in.)

[Hagen]

Rule #1
LMCE should be the DHCP server

Rule #2
There should not be other DHCP servers

Rule #3
LMCE is more than a media centre

At worst, if you have set up a lot of port forwarding or access trough your router just disable the LMCE internal firewall (in the web admin) and rely on the router as firewall.

And you might have found a bit more with a search 'single NIC', if you find 'too many posts to comb trough' then narrow your search.

[teedge77]

Rule #4
Theres exceptions to every rule (ie "rule 1")

Zaerc admires some who take the path of most resistance and despises others. I wouldnt worry much about it. Definitely search exhaustively before asking for help though.

[Zaerc]

Rule #4
Theres exceptions to every rule (ie "rule 1")

Zaerc admires some who take the past of most resistance and despises others. I wouldnt worry much about it. Definitely search exhaustively before asking for help though.

I'm so glad you're around to tell me what I admire and despise...

[teedge77]

sure thing. oh...and i fixed it....path...not past...

http://forum.linuxmce.org/index.php?topic=2639.0


and i dont think i need to post how many people you despise.   

[Matthew]

The best way is to use 2 network cards and put the LMCE core (or hybrid) in between the internet and the rest of your network and let the lmce core do the DHCP on the internal network. http://wiki.linuxmce.org/index.php/Why_dual_network_cards%3F

Is that the answer you were looking for?  Because I can't make heads or tails out of your question (both times), beyond that it seems to have something to do with DHCP and a single NIC setup.   Try reading: http://www.catb.org/~esr/faqs/smart-questions.html maybe that helps a bit.

I was perfectly clear in specifying that I have a single NIC. Others have had no trouble either understanding the question or replying helpfully. I recommend you studying the wisdom of not saying anything if you don't have anything helpful to say.

Also feel free to update the FAQ, it is in the WIKI after all, but aparently nobody that "suffered" from this horrendous problem seemed to care enough to bother.

When I've got a tested answer, I'll update the FAQ. I did post it keeping in mind that a single NIC setup on a cablemodem or other router whose DHCP might not be optional is likely a popular situation that LMCE can probably handle if configured right, so others will probably benefit from a correct answer if I find it. People who have something useful to offer, other than flames, get the useful info before answering the question. And don't post merely self indulgent flames that damage the community.

Now if you'll excuse me, I have other things to do besides answering the same question over and over and over again, just because some people who can't figure things out for themselves don't feel like using the recommended setup.  And just to get things straight, your self inflicted problem is not my responsability.

I didn't ask you to take responsibility for this problem, which I "inflicted" on myself by doing a basic LMCE install according to its instructions, which left me with a system with basic defects (like not routing to the Internet). You volunteered your low S/N posts yourself - why bother, when you could be doing something useful?

Is there anything else you'd like to lecture us on?

No, I think you've got enough to work on for now.

[teedge77]

single nic might have been a better search than dhcp. there can be a few hoops to jump through to get the single nic setup working correctly. it might tell you how to change the dhcp settings to work with the single nic setup and you can work it so that you are changing it to use the dhcp from the other dhcp server. you might try this one

http://forum.linuxmce.org/index.php?topic=1367.0

i tried for a while to do the single nic but it was easier to just vlan the switch instead. sorry if this wasnt much help.

[Hagen]

Put it this way, if the core is not the DHCP server it requires you to have all your media on the core itself.
You can't use other MDs (less they all be independent neutered cores).
You woun't find any media on any other machine (without a bunch of hassle and manual set-up)
You can't stream any content.. oh, I allready covered that...

Basicly you'll be having a dumb neutered box, and if that's what you want you can simply switch the internal DHCP off in the web-admin.
(requires a reboot as well)
For such a use 'mediaportal' might arguably be better.