====== Interface Configuration for IP ====== For illustrative purposes I will describe the configuration of a desktop PC with a static IP address ''192.168.//x//.//y//'' using the default gateway ''192.168.//x//.1''. You should lookup and make a note of the values to use of //x// and //y// for the host you are configuring. These are to be found in **Table 2** below. You should replace //x// and //y// found in the following by the actual values that you have noted. ===== Check the Loopback interface ===== This should already be configured: icct@myhost:~$ ifconfig lo lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:11132 errors:0 dropped:0 overruns:0 frame:0 TX packets:11132 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:1009788 (986.1 KiB) TX bytes:1009788 (986.1 KiB) Check it works using: icct@myhost:~$ ping localhost PING localhost.localdomain (127.0.0.1) 56(84) bytes of data. 64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=1 ttl=64 time=0.050 ms 64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=2 ttl=64 time=0.045 ms 64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=3 ttl=64 time=0.048 ms 64 bytes from localhost.localdomain (127.0.0.1): icmp_seq=4 ttl=64 time=0.050 ms ^C --- localhost.localdomain ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 2999ms rtt min/avg/max/mdev = 0.045/0.048/0.050/0.005 ms ===== Wire up the network ===== First wire up the network. Power up the hubs and wire up the network so that it matches the physical layout of the map shown in **Figure 1** in the [[http://77.68.39.12/dokuwiki/|our configuration]]. * the first interface (''eth0'') of each cluster server, the server ''venus'' and one of the switched LAN ports on the Linksys router should be connected to the first hub (the hub is essentially the backbone of the ''icct-net'' network which as the network address ''192.168.1.0''). * the second interface (''eth1'') of the ''jupiter'' server and each of the hosts in ''jupiter-net'' should be connected to the second hub which represents network ''192.2.2.0''. * the second interface (''eth1'') of the ''saturn'' server and each of the hosts in ''saturn-net'' should be connected to the second hub which represents network ''192.2.3.0''. Note that the cluster servers each have two interfaces. These will be configured as routers from ''jupiter-net'' and ''saturn-net'' to ''icct-net'' and //vice versa//. ===== Configure the Ethernet interface on each host ===== To set up the rest of the network we make use of two basic tools ifconfig and route (see Chapter 4 of Bautts //et al.//, 2005((Tony Bautts, Terry Dawson and Gregor N. Purdy, Linux Network Administer's Guide, 3rd Ed., O'Reilly Media Inc., 2005. The 2nd edition is available online as http://www.oreilly.com/catalog/linag2/book/index.html.)) for general settings and the [[http://www.debian.org/doc/manuals/reference/ch-gateway.en.html|Network Configuration chapter]] of the Debian Reference((Chapter 10 -- Network Configuration, Debian Reference, http://www.debian.org/doc/manuals/reference/ch-gateway.en.html.)) for Debian/Ubuntu specific information). We cannot issue these commands from the command line, as implied in Bautts //et al.//, so they have to be set in the special file ''/etc/network/interfaces''. Example settings that you can use are to be found in the example ''/etc/networking/interface'' ((Example ''/etc/networking/interface'' file. Installed in the Ubuntu documentation set in file : ''/usr/share/doc/ifupdown/examples/network-interfaces''.)).You will be configuring the hosts as shown in **Table 2** to which you should refer in the following. Remember that for illustrative purposes I am using the hostname myhost with IP address ''192.168.x.y''. **Table 2**: //Static IP Address Settings for Hosts// ^ Host ^ Interface ^ Static IP Address ^ Netmask ^ Gateway Address ^ | ''venus'' | ''eth0'' | ''192.168.1.2'' | ''255.255.255.0'' | ''192.168.1.1'' | | ''jupiter'' | ''eth0'' | ''192.168.1.3'' | ''255.255.255.0'' | ''192.168.1.1'' | | | ''eth1'' | ''192.168.2.1'' | ''255.255.255.0'' | ''192.168.1.3'' | | ''callisto'' | ''eth0'' | ''192.168.2.2'' | ''255.255.255.0'' | ''192.168.2.1'' | | ''europa'' | ''eth0'' | ''192.168.2.3'' | ''255.255.255.0'' | ''192.168.2.1'' | | ''ganymede'' | ''eth0'' | ''192.168.2.4'' | ''255.255.255.0'' | ''192.168.2.1'' | | ''saturn'' | ''eth0'' | ''192.168.1.4'' | ''255.255.255.0'' | ''192.168.1.1'' | | | ''eth1'' | ''192.168.3.1'' | ''255.255.255.0'' | ''192.168.1.4'' | | ''dione'' | ''eth0'' | ''192.168.3.2'' | ''255.255.255.0'' | ''192.168.3.1'' | | ''tethys'' | ''eth0'' | ''192.168.3.3'' | ''255.255.255.0'' | ''192.168.3.1'' | | ''titan'' | ''eth0'' | ''192.168.3.4'' | ''255.255.255.0'' | ''192.168.3.1'' | To set up your Ethernet interface on a desktop machine you need to convert your settings from DHCP to Static IP addressing. Edit the file ''/etc/network/interfaces'' and look for the line which reads: iface eth0 inet dhcp auto eth0 Replace this by a configuration of IP address, netmask and gateway based on the following: auto eth0 iface eth0 inet static address 192.168.x.y network 192.168.x.0 netmask 255.255.255.0 gateway 192.168.x.1 This setting assigns the IP address ''192.168.x.y'' to the first Ethernet interface ''eth0''. From the entries in ''/etc/hosts'', the system knows that an alias of this interface is ''myhost''. The netmask ''255.255.255.0'' ensures that ''myhost'' is made part of the subnet ''192.168.x.0'' rather than the larger network ''192.168.0.0''. The ''gateway'' setting tells the operating system that any packets that are not for the network ''192.168.x.0'' should be forwarded through interface ''192.168.x.1''. To restart the network with these new settings use: icct@myhost:~$ sudo /etc/init.d/networking restart Now check using ''sudo ifconfig eth0'' and you should see something like: eth0 Link encap:Ethernet HWaddr 00:40:D0:2E:EE:6B inet addr:192.168.x.y Bcast:192.168.x.255 Mask:255.255.255.0 inet6 addr: fe80::240:d0ff:fe2e:ee6b/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:302 errors:0 dropped:0 overruns:0 frame:0 TX packets:753 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:348172 (340.0 KiB) TX bytes:45775 (44.7 KiB) Interrupt:10 Base address:0xe400 From this you should note that the system has changed the IP address and netmask and has automatically set the broadcast address (''192.168.x.255''). It has also set the Maximum Transfer Unit (MTU) to 1500 bytes which is the largest packet size that Ethernet can carry. This completes the basic configuration and each desktop host on a subnet should be able to "see" each other. To confirm this, use //ping//. For example from ''dione'' use ''ping titan'' to check that the interface on ''dione'' can send data to ''titan''. Do the same from ''titan'' to ''dione''. Check the settings by issuing: icct@myhost:~$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.x.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 0.0.0.0 192.168.x.1 0.0.0.0 UG 1 0 0 eth0 ---- [[eg-253:network:step2|Previous Step]] | [[eg-253:network:home|Home]] | [[eg-253:network:step4|Next Step]]