Nic card configuration on the server

Most of the configuration for your nic cards is handled by the file /etc/rc.d/rc.inet1.conf this file holds the config settings that get used when you run your /etc/rc.d/rc.inet1 executable. I just happened to stumble on it when I was doing all this, lucky I did ! The last part where I define “gateway” is the gateway provided by my isp, its not some other computer on my local network (obviously from the format) you will need to get this value, you cant use my config without it.

Setting up your /etc/rc.d/rc.inet1.conf

1. Edit your /etc/rc.d/rc.inet1.conf
2. This is what mine looks like edit yours accordingly

   # /etc/rc.d/rc.inet1.conf
   #
   # This file contains the configuration settings for network interfaces.
   # If USE_DHCP[interface] is set to "yes", this overrides any other settings.
   # If you don't have an interface, leave the settings null ("").
    
   # You can configure network interfaces other than eth0,eth1... by setting
   # IFNAME[interface] to the interface's name. If IFNAME[interface] is unset
   # or empty, it is assumed you're configuring eth.
    
   # Several other parameters are available, the end of this file contains a
   # comprehensive set of examples.
    
   # =============================================================================
    
   # Config information for eth0:(this is the 3com card 30)
   IPADDR[0]=""
   NETMASK[0]=""
   USE_DHCP[0]="yes"
   DHCP_HOSTNAME[0]=""
    
   # Config information for eth1: (this is the built in card i think
   IPADDR[1]="192.168.10.1"
   NETMASK[1]="255.255.255.0"
   USE_DHCP[1]=""
   DHCP_HOSTNAME[1]=""
    
   # Config information for eth2: (this is the gigabit card 01)
   IPADDR[2]="192.168.1.200"
   NETMASK[2]="255.255.255.0"
   USE_DHCP[2]=""
   DHCP_HOSTNAME[2]=""
    
   # Config information for eth3:
   IPADDR[3]=""
   NETMASK[3]=""
   USE_DHCP[3]=""
   DHCP_HOSTNAME[3]=""
    
   # Default gateway IP address:
   GATEWAY="98.195.216.1"
    
   # Change this to "yes" for debugging output to stdout.  Unfortunately,
   # /sbin/hotplug seems to disable stdout so you'll only see debugging output
   # when rc.inet1 is called directly.
   DEBUG_ETH_UP="yes"
    
   ## Example config information for wlan0.  Uncomment the lines you need and fill
   ## in your info.  (You may not need all of these for your wireless network)
   #IFNAME[4]="wlan0"
   #IPADDR[4]=""
   #NETMASK[4]=""
   #USE_DHCP[4]="yes"
   #DHCP_HOSTNAME[4]="icculus-wireless"
   #DHCP_KEEPRESOLV[4]="yes"
   #DHCP_KEEPNTP[4]="yes"
   #DHCP_KEEPGW[4]="yes"
   #DHCP_IPADDR[4]=""
   #WLAN_ESSID[4]=BARRIER05
   #WLAN_MODE[4]=Managed
   ##WLAN_RATE[4]="54M auto"
   ##WLAN_CHANNEL[4]="auto"
   ##WLAN_KEY[4]="D5AD1F04ACF048EC2D0B1C80C7"
   ##WLAN_IWPRIV[4]="AuthMode=WPAPSK EncrypType=TKIP WPAPSK=7B1ABEEB5D197741923ED26727569C365E31212096A0EAFAD563B268BAD01CAF TxRate=0"
   #WLAN_WPA[4]="wpa_supplicant"
   #WLAN_WPADRIVER[4]="ndiswrapper"
    
   ## Some examples of additional network parameters that you can use.
   ## Config information for wlan0:
   #IFNAME[4]="wlan0"              # Use a different interface name nstead of
                                   # the default 'eth4'
   #HWADDR[4]="00:01:23:45:67:89"  # Overrule the card's hardware MAC address
   #MTU[4]=""                      # The default MTU is 1500, but you might need
                                   # 1360 when you use NAT'ed IPSec traffic.
   #DHCP_KEEPRESOLV[4]="yes"       # If you dont want /etc/resolv.conf overwritten
   #DHCP_KEEPNTP[4]="yes"          # If you don't want ntp.conf overwritten
   #DHCP_KEEPGW[4]="yes"           # If you don't want the DHCP server to change
                                   # your default gateway
   #DHCP_IPADDR[4]=""              # Request a specific IP address from the DHCP
                                   # server
   #WLAN_ESSID[4]=DARKSTAR         # Here, you can override _any_ parameter
                                   # defined in rc.wireless.conf, by prepending
                                   # 'WLAN_' to the parameter's name. Useful for
                                   # those with multiple wireless interfaces.
   #WLAN_IWPRIV[4]="AuthMode=WPAPSK EncrypType=TKIP WPAPSK=thekey TxRate=0"
                                   # Some drivers require a private ioctl to be
                                   # set through the iwpriv command. If more than
                                   # one is required, you can place them in the
                                   # IWPRIV parameter (space-separated, see the
                                   # example).

   So, in my configuration remember that eth0 is for the internet the other two are for local lan, the third one is the default.

   The gateway from your ISP
   

   The most IMPORTANT thing, that isn’t really straightforward is the “gateway” that ip address is the gateway provided by my ISP. The only way I could find that value was to plug in my old router, go to the status and get it. If you do plug in your old router to get this value get the DNS servers also, If you can just print the whole page your router gives you its gold.

   Restarting everything

   At this point we just want to restart all the network stuff, so type in these commands in your /etc/rc.d/

   cd /etc/rc.d/
   ./rc.inet1 restart
   ./rc.inet2 restart
   ./rc.inetd restart
   ./rc.iptables

   Not sure if they are all needed, but restarting them does not hurt. Also if you have a webserver restart that with “./rc.httpd restart”

   If your running a web server

   If you had a web server running before you started, you should note now that a lot of ip’s have changed. If you had specified ip’s in your virtualhost settings in httpd.conf go back and change them all to *. This way its name based virtual hosts and the ip’s don’t matter. When I first did this all I would get from my webserver was a directory listing, of course I got everything else working before I was testing my webserver though !

   Testing at this point

   Well, hopefully we setup the server as a nat. There is not much you can test at this point. Since I’m not running a dhcp server when I start up my computers that are connected to my server they will ask server for a ip and the server wont give it to them, at that point everything stops. Sorry, we need to go setup at least one computer before we can test. In hindsight a dhcp server on the linux box is much more convient, it makes it so the computers can just automatically get their ip’s and you would be done at this point. But, I didnt do it this way, its not that much harder to setup your nic configs on the client machines, but later I’ll write a article when I setup dhcp on my server.
   You should be able to ping places like yahoo.com from your server at this point, if your server does not have internet access nothing connected to it will either. Type in ifconfig and make sure everything looks alright, make sure eth0 has a internet ip.

   Quick setup on a windows machine

   Im using windows XP, not that unspeakable garbage that came after it. If your setting up a router you should be pretty familiar with this stuff. You basically need to setup the settings so your pc knows its static ip, gateway, and DNS servers. These will be the instructions for a windows machine on the subnetwork 192.168.10.x, it’s the 100Mbs network.

   1. Go to your network connection
   2. Right click the network connection you are connecting to the server and click properties
   3. Click the “internet protocol tcp/ip” and click properties
   4. Give it a static ip for its network, eg. If your nic on the server is 192.168.X.X set this ones static ip to 192.168.X.X+1
      NOTE: the third octal in the ip address is the network, so if your setting up two different lans like me then you need to make it the same as the nic you are connecting it to. So in my case I connected the normal computers to 192.168.10.1 and I gave them ip’s like 192.168.10.1
   5. Set subnet mask 255.255.255.0
   6. Set gateway to the ip of the nic that you are connecting to on the server eg. 192.168.10.1
   7. Set the DNS’s to the DNS ip addresses your ISP uses, I got these values from my router. You need to put something in here or you wont be able to browse webpages.
      NOTE: if you can access shares on server and ping the server and ip addresses on the internet but you cannot ping places like yahoo.com or google.com your problem is step 7, your either using the wrong DNS or you haven’t set it.

   You should be able to connect to your server and the internet through your server now. If not try restarting the computer, if you still cant try and ping the server, make sure your connected to the right nic.

   Connecting a linux machine

   Im using ubuntu on the machine im connecting. You might be using another distro. The setup is pretty straightforward. We need to do what we did in windows, set ip, set gateway, set dns’s. Ill give the instructions for the Ubuntu machine connected to the 192.168.1.x network.

   1. Edit /etc/network/interfaces this is how I set mine (setup ip’s and gateway)

      auto lo
      iface lo inet loopback
       
      #our inet interface to the server
      auto eth0
      iface eth0 inet static
      address 192.168.1.11
      gateway 192.168.1.200
      netmask 255.255.255.0
      network 192.168.1.0
      broadcast 192.168.1.255

   2. Edit /etc/ resolv.conf this isn’t generated by network manager J (setup dns’s)

      # Generated by NetworkManager
      nameserver 68.87.85.98

   3. Restart your network “sudo /etc/init.d/networking restart”

   Finished

   That’s it. Now, hopefully everything works, if not you will have to use sound, logical reasoning to narrow down the problems. Every network is different so its kinda hard for people to help you with really detailed stuff like this. Once you get to this point, you are the last hope for your network, there are no heroes out there that can save you.

   Conclusions

   This gives you much greater control over your network. Now I have two subnetworks that can’t see each other, but can see the internet, and the server. This way you can setup your wifi to be completely separate from the rest of your network, but allow wifi users to connect to the internet through it.

   A note on crossovers
   

   If you are connecting a computer to a computer like I am you will need a crossover cable, I’m not a very patient person so I made one. I also ordered a “crossover converter” from ebay for a few bucks. Its not very hard to make a “converter” or to just rewire your cable a little. Pretty much you need to swap two pairs of wires, so all together from the eight pins you just mess with four.

   I did something like this http://www.instructables.com/id/Crossover-Dongle/ but not as pretty J

   

   Ill just use that till my other converter shows up, so far its working ok. I actually cut a old cable and took the connector off of a old 3com nic.

   How much speed did I get from my gigabit Ethernet ?
   

   One of the main goals of all this was to allow two computers to share gigabit Ethernet without having to buy a router. So, how much of a boost did I get.

   I tested my gigabit connection and I tested my other sub network connection between two 100Mbs. My tests were quick and dirty, I did all the conversions myself and just looked at the time to see how long it would take for it to transmit a ~700meg file.

   Below are all my calculations. What I found was that I’m only getting about 17% of what I should from my gigabit Ethernet which is about 169Mbs. For the 100Mbs I’m only getting about 65% of what I should which is about 65Mbs. So even though my throughput is horrible im still going almost three times as fast. I’m pretty sure the low bandwidth is from a bottleneck on the server pci bus speed or my Ethernet cable. Ill troubleshoot it later.

   transfer of file: size 716,808 KB or 716808000 bytes or 5734464000 bits

   @gigabit, time ~34seconds; speed 168,660,705.88 or about 169Mbs ; eff=17%

   @100Mbs, time ~88seconds; speed 65,164,363.63 so about 65Mbs ; eff=65%

   Equation I derived Speed=size in bytes / time in seconds

   What’s Next ?

   Well, the next thing I need to tackle is a better understanding of iptables. I always need to route ports and such for playing games. Like we play nexiuz a lot and I need to be able to forward port 26000 to the machine im playing on. Also I plan on reusing my old router to give me better wifi signal upstairs and outside.

   Further reading

   http://www.makeitsimple.com/how-to/dyi_crossover.htm (how crossovers work)

   http://www.yolinux.com/TUTORIALS/LinuxTutorialIptablesNetworkGateway.html

   http://www.yolinux.com/TUTORIALS/LinuxTutorialNetworking.html (good tutorial)

   http://www.slackware.com/~alien/efg/ (generates iptables config, I didn’t use but might later)