Weird Network problems....

[mcmanus69]

Haven't posted in a while (which means no probs! :D ) but I finally ran into a snag...

Okay, my problem is this (and I can't find ANY information about it...):

1.) I am running MDK8.1 now, and using default kernel. I am using cable modem, and sometimes I run my computer straight into the modem, and sometimes I run it through a router. However, whenever I switch back & forth, I get bad network problems. Internet works fine, but apps (GAIM, mcedit, etc.) have a problem loading.... they seem to be timing out or something on 'lo' before they finally snap back to life and try the internet and then whala, everything works. It also sez my hostname is "dhcp-441-14" and it can't find it, etc. etc. etc. The only thing I have in /etc/hosts is "127.0.0.1 localhost.localdomain localhost" (which is normal).. so my question, where is it setting that dhcp-441-14 hostname, and when/where is dhcpcd being called? I'd like to understand the underlying network structure of linux better. Thanx.

2.) How do you change firewall settings from 'medium' back to 'low' or 'off'... I think the firewall is giving me problems... I can't seem to find the option for it. (and I have a firewall running on my router, so I'm still pretty secure, heh)

3.) I recently compiled a linux kernel w/out 'lo' evidently. I searched for it, but couldn't find the option for it. all new kernels have no 'lo' protocol/interface (whatever) so it's doing the same timeout thing as above (question #1). Maybe the 2 are linked.... any help? Thanx!!!

Linux networking sure is complicated, and the GUI tools don't fix anything, or maybe I'm not doing something right. blech....

[ 10 October 2001: Message edited by: mcmanus69 ]

[mcmanus69]

*sigh*... linux is such a mystery...
problem #1 is gone, very mysteriously, and I found out 'draksec' can set the security options, so problem #2 is now gone, too. Only problem left is #3. Linux networking still remains a mystery to me, heh....


Actually, problem #1 is not completely gone. My hostname (when connected to the internet) is still dhcp-441-14. If anyone knows how to change that (where/when dhcpcd is being called is my guess), I'd be happy to know, thx.

[ 10 October 2001: Message edited by: mcmanus69 ]

[mcmanus69]

Okay, well, I found out where to change the hostname... /bin/hostname duh. hehe... but that's more of a temporary fix, and I still would like to find out where/when 'dhcpcd' is being called. Anyone know? THX.

[mrBen]

dhcpcd is called during bootup. It'll be in one of them confusing rc.d type directories ;)

Networking is a bit of a black art in Linux. I was trying to set up a dhcp server, but it keeps trying to run dhcpcd first, which is a bit crap because then the server is trying to listen for an address, which obviously isn't there.

I think I might give up dhcp for a while and go for straight networking. Not that I know how to do that really either :(

[mcmanus69]

heh, that's what I thought.... I searched for it, but eventually gave up. Oh well. I wouldn't mind so much if there wuzn't such an impact on 'performance'. All apps seem to be waiting for SOMETHING to time-out before they start to run. Oh well................ I've been reading a lot of info, and I did find out that dhcpcd sets the hostname... but what's weird is that the whole system seems to get fubar'ed whenever I plug directly into the cable modem... *sigh*... I think I'll just stick to using my router box, hehe...

[DMR]

Cable modems read (and store) the MAC address of the network device you plug into them, so when you switch between your Linux box and the router, you should power down the modem. After you connect your interface, repower the modem to allow it to get the new MAC address when it initializes.

[Joeri Sebrechts]

When you compile in tcp/ip support into your kernel you automatically get lo support. The reason you're not seeing a lo is most likely errors in your interface configuration files. I don't know which files are meant to do this, but on my debian system it's the /etc/network/interfaces file, and that contains the following section:

auto lo
iface lo inet loopback

which sets up a loopback interface apparently. I'd suggest you look in the networking configuration files in your /etc dir for a file that contains your network interfaces and figure out how to add your loopback interface there (not much help, I know)