On 05/17/2012 10:51 PM, Sanjay Arora wrote: > Hello all > > I am setting up a Centos 6 machine with one network card& one onboard > network port. Both are recognized& work. Onboard Network port is unused > yet, but is required for dedicated access to LTSP LAN, which would allow > older PIII machines to boot from this system. I have installed LTSP but > again Networking seems to be the problem area, as the clients won't boot > from this machine. > > Have muddled& tinkered with Networking a bit...deleted& reconfigured the > ifcfg files again& again but as I don't understand NetworkManager and > Google is not helping get relevant results, so I have brought the system to > minimum working condition, where one network card is providing LAN access > on which Internet Router is configured. And now I am posting my system's > condition below as output of various commands. > > My network-scripts directory: > > [root at swyam network-scripts]# ls > ifcfg-Internet_GW ifup-eth > ifcfg-lo ifup-ippp > ifdown ifup-ipv6 > ifdown-bnep ifup-isdn > ifdown-eth ifup-plip > ifdown-ippp ifup-plusb > ifdown-ipv6 ifup-post > ifdown-isdn ifup-ppp > ifdown-post ifup-routes > ifdown-ppp ifup-sit > ifdown-routes ifup-tunnel > ifdown-sit ifup-wireless > ifdown-tunnel init.ipv6-global > ifup net.hotplug > ifup-aliases network-functions > ifup-bnep network-functions-ipv6 > > Ifconfig output: > > [root at swyam network-scripts]# ifconfig > eth0 Link encap:Ethernet HWaddr E0:69:95:77:A7:F3 > UP BROADCAST MULTICAST MTU:1500 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) > Interrupt:20 Memory:fe600000-fe620000 > > eth1 Link encap:Ethernet HWaddr 00:60:52:0C:0B:DE > inet addr:192.168.1.3 Bcast:192.168.1.255 Mask:255.255.255.0 > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:2245698 errors:0 dropped:0 overruns:0 frame:0 > TX packets:1785431 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:3105161344 (2.8 GiB) TX bytes:148843277 (141.9 MiB) > Interrupt:16 Base address:0x2000 > > lo Link encap:Local Loopback > inet addr:127.0.0.1 Mask:255.0.0.0 > UP LOOPBACK RUNNING MTU:16436 Metric:1 > RX packets:525 errors:0 dropped:0 overruns:0 frame:0 > TX packets:525 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:53459 (52.2 KiB) TX bytes:53459 (52.2 KiB) > > [root at swyam network-scripts]# cat ifcfg-Internet_GW > TYPE=Ethernet > BOOTPROTO=none > IPADDR=192.168.1.3 > PREFIX=24 > GATEWAY=192.168.1.1 > DNS1=218.248.245.1 > DNS2=8.8.8.8 > DOMAIN="218.248.245.1 8.8.8.8 8.8.4.4" > DEFROUTE=yes > IPV4_FAILURE_FATAL=yes > IPV6INIT=no > NAME="Internet GW" > UUID=d4535709-a05b-459d-a4fd-f08ec9460bcc > ONBOOT=yes > DNS3=8.8.4.4 > > Network Manager is running and the above card "Internet_GW" was configured > through the NetworkManager applet. Internet works. One can disconnect > Internet through the NetworkManager applet. Yet the applet's Edit > Connection --> Wired --> Last Used status shows "Never". > > Now let's come to what I want to do with this machine....The Onboard > network port for LTSP services....Network card on network > 192.168.1.0/24(192.168.1.1 is the ISP ADSL router) to provide LAN > access& Internet > access. > > Now what I want to do is to create a third network for my virtual machines > (KVM) say 172.16.1.1/24. Now create some sort of dummy bridge and get these > machines talking to the Internet....said bridge to either forward the > packets through the normal Internet path or somehow use NAT to do it. I > think this should be doable but haven't come across any example or any > tutorial for this. > > Now comes why I want a separate network....why not use > 192.168.1.0/24...problem is...I don't want to disable Network Manager by > putting Managed=NO in my ifcfg file. As with Network Manager enabled, I can > use USB devices whenever my ISP goes down....and I'm afraid it happens more > frequently than I care to bear. > > I frankly also don't understand how Network Manager works....in a broad > manner....literature I found was either too technical or too old or was > focussed on a particular problem. > > I would like to know a network/bridge/device topology that can solve my > issue....three networks...lan. ltsp, virtual machines, all having access to > each other& the net, while keeping the option of using networkmanager or > any other tool (I'm open) to plugin any other wireless internet access > device. > > I am not very advanced admin, but can follow instructions. > > Kindly help. > NetworkManager does not (as far as I know) use ifcfg files unless you select "Available for all users" checkbox, but rather keeps interface data somewhere inside $HOME directory (.gconf subdirectory maybe) in unreadable format for humans. "Available for all users" will help you, or run "network" service and disable "NetworkManager" service. -- Ljubomir Ljubojevic (Love is in the Air) PL Computers Serbia, Europe Google is the Mother, Google is the Father, and traceroute is your trusty Spiderman... StarOS, Mikrotik and CentOS/RHEL/Linux consultant