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I just installed Ubuntu 12.10 on about 30 computers at a high school computer lab (and deleted Win XP and Win 7). The problem that I have now is that we are unable to access the internet over our network.

The school has an aDSL router and a single ethernet cable that comes to the computer lab. This cable connects to a 24 port Trendnet Ethernet Switch. Half of the computers are connected to this switch. Another ethernet cable goes from this switch to an identical switch across the lab giving internet access to the other half of the computers. I did not set up the network this way, but it used to work when the computers had windows loaded on them. After installing ubuntu we no longer have internet connectivity over the network.

When I connect the ethernet cable from the aDSL router directly to one of the computers the internet works properly, but when I connect it to the switch we get nothing. Ubuntu does not even assign local ip addresses to the computer when set to automatic DHCP. I tried setting manual ip addresses outside the DHCP range: I set the ip address to 192.168.1.101 through 192.168.1.130. I set the gateway to 192.168.1.1, the subnet mask to 255.255.255.0 and the DNS router to 192.168.1.1. I later switched the DNS router to opendns's ip addresses.

Setting the ip addresses manually did allow me to ping computers on the local network as long as the were on the same switch. It would time out if the computer were on the other switch or if they were outside the local network and still no internet access.

I also tried restarting the router and the switches with no luck.

Does anyone have any suggestions about how to access the internet over our local network and how to network the computers across both switches?

EDIT:

Here is what the syslog gives me:

computer8 dbus[835]: [system] Successfully activated service 'org.freedesktop.PolicyKit1'
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: init!
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: update_system_hostname
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPluginIfupdown: management mode: unmanaged
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/pci0000:00/0000:00:05.0/0000:02:00.0/net/eth0, iface: eth0)
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: device added (path: /sys/devices/pci0000:00/0000:00:05.0/0000:02:00.0/net/eth0, iface: eth0): no ifupdown configuration found.
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/lo, iface: lo)
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/lo, iface: lo): no ifupdown configuration found.
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: end _init.
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> Loaded plugin ifupdown: (C) 2008 Canonical Ltd.  To report bugs please use the NetworkManager mailing list.
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> Loaded plugin keyfile: (c) 2007 - 2010 Red Hat, Inc.  To report bugs please use the NetworkManager mailing list.
Feb 19 16:18:59 computer8 NetworkManager[902]:    Ifupdown: get unmanaged devices count: 0
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: (-1240455032) ... get_connections.
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: (-1240455032) ... get_connections (managed=false): return empty list.
Feb 19 16:18:59 computer8 NetworkManager[902]:    keyfile: parsing Wired connection 1 ... 
Feb 19 16:18:59 computer8 NetworkManager[902]:    keyfile:     read connection 'Wired connection 1'
Feb 19 16:18:59 computer8 NetworkManager[902]:    Ifupdown: get unmanaged devices count: 0
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> modem-manager is now available
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> monitoring kernel firmware directory '/lib/firmware'.
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> WiFi enabled by radio killswitch; enabled by state file
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> WWAN enabled by radio killswitch; enabled by state file
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> WiMAX enabled by radio killswitch; enabled by state file
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> Networking is enabled by state file
Feb 19 16:18:59 computer8 NetworkManager[902]: <warn> failed to allocate link cache: (-10) Operation not supported
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): carrier is OFF
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): new Ethernet device (driver: 'r8169' ifindex: 2)
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): exported as /org/freedesktop/NetworkManager/Devices/0
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): now managed
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): device state change: unmanaged -> unavailable (reason 'managed') [10 20 2]
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): bringing up device.
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): preparing device.
Feb 19 16:18:59 computer8 NetworkManager[902]: <info> (eth0): deactivating device (reason 'managed') [2]
Feb 19 16:18:59 computer8 NetworkManager[902]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring...
Feb 19 16:18:59 computer8 NetworkManager[902]: <warn> /sys/devices/virtual/net/lo: couldn't determine device driver; ignoring...
Feb 19 16:18:59 computer8 kernel: [   15.621206] r8169 0000:02:00.0: >eth0: link down
Feb 19 16:18:59 computer8 kernel: [   15.621396] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
Feb 19 16:18:59 computer8 kernel: [   15.621674] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready
Feb 19 16:18:59 computer8 avahi-daemon[905]: Network interface enumeration completed.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Registering HINFO record with values 'I686'/'LINUX'.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Server startup complete. Host name is computer8.local. Local service cookie is 2464504904.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Service "computer8" (/services/udisks.service) successfully established.
Feb 19 16:18:59 computer8 anacron[996]: Anacron 2.3 started on 2013-02-19
Feb 19 16:18:59 computer8 acpid: starting up with proc fs
Feb 19 16:18:59 computer8 cron[966]: (CRON) INFO (pidfile fd = 3)
Feb 19 16:18:59 computer8 kernel: [   15.777742] Bridge firewalling registered
Feb 19 16:18:59 computer8 avahi-daemon[905]: Joining mDNS multicast group on interface lxcbr0.IPv4 with address 10.0.3.1.
Feb 19 16:18:59 computer8 avahi-daemon[905]: New relevant interface lxcbr0.IPv4 for mDNS.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Registering new address record for 10.0.3.1 on lxcbr0.IPv4.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Withdrawing address record for 10.0.3.1 on lxcbr0.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Leaving mDNS multicast group on interface lxcbr0.IPv4 with address 10.0.3.1.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Interface lxcbr0.IPv4 no longer relevant for mDNS.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Joining mDNS multicast group on interface lxcbr0.IPv4 with address 10.0.3.1.
Feb 19 16:18:59 computer8 avahi-daemon[905]: New relevant interface lxcbr0.IPv4 for mDNS.
Feb 19 16:18:59 computer8 avahi-daemon[905]: Registering new address record for 10.0.3.1 on lxcbr0.IPv4.
Feb 19 16:18:59 computer8 NetworkManager[902]: <warn> /sys/devices/virtual/net/lxcbr0: couldn't determine device driver; ignoring...
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: devices added (path: /sys/devices/virtual/net/lxcbr0, iface: lxcbr0)
Feb 19 16:18:59 computer8 NetworkManager[902]:    SCPlugin-Ifupdown: device added (path: /sys/devices/virtual/net/lxcbr0, iface: lxcbr0): no ifupdown configuration found.
Feb 19 16:19:00 computer8 cron[1048]: (CRON) STARTUP (fork ok)
Feb 19 16:19:00 computer8 cron[1048]: (CRON) INFO (Running @reboot jobs)
Feb 19 16:19:00 computer8 ntpdate[1051]: Can't find host ntp.ubuntu.com: Name or service not known (-2)
Feb 19 16:19:00 computer8 ntpdate[1051]: no servers can be used, exiting
Feb 19 16:19:00 computer8 kernel: [   15.855197] ip_tables: (C) 2000-2006 Netfilter Core Team
Feb 19 16:19:00 computer8 kernel: [   15.865021] nf_conntrack version 0.5.0 (11983 buckets, 47932 max)
Feb 19 16:19:00 computer8 dnsmasq[1073]: started, version 2.63rc6 cachesize 150
Feb 19 16:19:00 computer8 dnsmasq[1073]: compile time options: IPv6 GNU-getopt DBus i18n IDN DHCP DHCPv6 no-Lua TFTP conntrack
Feb 19 16:19:00 computer8 dnsmasq-dhcp[1073]: DHCP, IP range 10.0.3.2 -- 10.0.3.254, lease time 1h
Feb 19 16:19:00 computer8 dnsmasq[1073]: no servers found in /etc/resolv.conf, will  retry
Feb 19 16:19:00 computer8 dnsmasq[1073]: read /etc/hosts - 7 addresses
Feb 19 16:19:00 computer8 anacron[996]: Will run job `cron.daily' in 5 min.
Feb 19 16:19:00 computer8 anacron[996]: Jobs will be executed sequentially
Feb 19 16:19:00 computer8 dbus[835]: [system] Activating service name='org.freedesktop.Accounts' (using servicehelper)
Feb 19 16:19:00 computer8 accounts-daemon[1094]: started daemon version 0.6.21
Feb 19 16:19:00 computer8 dbus[835]: [system] Successfully activated service 'org.freedesktop.Accounts'
Feb 19 16:19:00 computer8 dbus[835]: [system] Activating service name='org.freedesktop.ConsoleKit' (using servicehelper)
Feb 19 16:19:00 computer8 dbus[835]: [system] Successfully activated service 'org.freedesktop.ConsoleKit'
Feb 19 16:19:01 computer8 kernel: [   17.130284] r8169 0000:02:00.0: >eth0: link up
Feb 19 16:19:01 computer8 kernel: [   17.130497] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> (eth0): carrier now ON (device state 20)
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> (eth0): device state change: unavailable -> disconnected (reason 'carrier-changed') [20 30 40]
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Auto-activating connection 'Wired connection 1'.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) starting connection 'Wired connection 1'
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> (eth0): device state change: disconnected -> prepare (reason 'none') [30 40 0]
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 1 of 5 (Device Prepare) scheduled...
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 1 of 5 (Device Prepare) started...
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 2 of 5 (Device Configure) scheduled...
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 1 of 5 (Device Prepare) complete.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 2 of 5 (Device Configure) starting...
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> (eth0): device state change: prepare -> config (reason 'none') [40 50 0]
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 2 of 5 (Device Configure) successful.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 3 of 5 (IP Configure Start) scheduled.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 2 of 5 (Device Configure) complete.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 3 of 5 (IP Configure Start) started...
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> (eth0): device state change: config -> ip-config (reason 'none') [50 70 0]
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 5 of 5 (IPv4 Configure Commit) scheduled...
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Beginning IP6 addrconf.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 3 of 5 (IP Configure Start) complete.
Feb 19 16:19:01 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 5 of 5 (IPv4 Commit) started...
Feb 19 16:19:01 computer8 avahi-daemon[905]: Joining mDNS multicast group on interface eth0.IPv4 with address 192.168.1.108.
Feb 19 16:19:01 computer8 avahi-daemon[905]: New relevant interface eth0.IPv4 for mDNS.
Feb 19 16:19:01 computer8 avahi-daemon[905]: Registering new address record for 192.168.1.108 on eth0.IPv4.
Feb 19 16:19:01 computer8 acpid: 33 rules loaded
Feb 19 16:19:01 computer8 acpid: waiting for events: event logging is off
Feb 19 16:19:01 computer8 acpid: client connected from 1067[0:0]
Feb 19 16:19:01 computer8 acpid: 1 client rule loaded
Feb 19 16:19:01 computer8 avahi-daemon[905]: Joining mDNS multicast group on interface lxcbr0.IPv6 with address fe80::ac67:41ff:fe66:c671.
Feb 19 16:19:01 computer8 avahi-daemon[905]: New relevant interface lxcbr0.IPv6 for mDNS.
Feb 19 16:19:01 computer8 avahi-daemon[905]: Registering new address record for fe80::ac67:41ff:fe66:c671 on lxcbr0.*.
Feb 19 16:19:01 computer8 dbus[835]: [system] Activating service name='org.freedesktop.UPower' (using servicehelper)
Feb 19 16:19:01 computer8 dbus[835]: [system] Successfully activated service 'org.freedesktop.UPower'
Feb 19 16:19:02 computer8 avahi-daemon[905]: Joining mDNS multicast group on interface eth0.IPv6 with address fe80::224:21ff:fea0:cfd0.
Feb 19 16:19:02 computer8 avahi-daemon[905]: New relevant interface eth0.IPv6 for mDNS.
Feb 19 16:19:02 computer8 avahi-daemon[905]: Registering new address record for fe80::224:21ff:fea0:cfd0 on eth0.*.
Feb 19 16:19:02 computer8 kernel: [   17.856246] IPv6: eth0: IPv6 duplicate address fe80::224:21ff:fea0:cfd0 detected!
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> (eth0): device state change: ip-config -> activated (reason 'none') [70 100 0]
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> DNS: starting dnsmasq...
Feb 19 16:19:02 computer8 NetworkManager[902]: <error> [1361251142.663612] [nm-dns-dnsmasq.c:390] update(): dnsmasq not available on the bus, can't update servers.
Feb 19 16:19:02 computer8 NetworkManager[902]: <error> [1361251142.663656] [nm-dns-dnsmasq.c:392] update(): dnsmasq owner not found on bus: Could not get owner of name 'org.freedesktop.NetworkManager.dnsmasq': no such name
Feb 19 16:19:02 computer8 NetworkManager[902]: <warn> DNS: plugin dnsmasq update failed
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> ((null)): writing resolv.conf to /sbin/resolvconf
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> Policy set 'Wired connection 1' (eth0) as default for IPv4 routing and DNS.
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> Activation (eth0) successful, device activated.
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> Activation (eth0) Stage 5 of 5 (IPv4 Commit) complete.
Feb 19 16:19:02 computer8 dbus[835]: [system] Activating service name='org.freedesktop.nm_dispatcher' (using servicehelper)
Feb 19 16:19:02 computer8 dbus[835]: [system] Successfully activated service 'org.freedesktop.nm_dispatcher'
Feb 19 16:19:02 computer8 NetworkManager[902]: <warn> dnsmasq appeared on DBus: :1.22
Feb 19 16:19:02 computer8 dnsmasq[1506]: started, version 2.63rc6 cache disabled
Feb 19 16:19:02 computer8 dnsmasq[1506]: compile time options: IPv6 GNU-getopt DBus i18n IDN DHCP DHCPv6 no-Lua TFTP conntrack
Feb 19 16:19:02 computer8 dnsmasq[1506]: DBus support enabled: connected to system bus
Feb 19 16:19:02 computer8 dnsmasq[1506]: warning: no upstream servers configured
Feb 19 16:19:02 computer8 NetworkManager[902]: <info> ((null)): writing resolv.conf to /sbin/resolvconf
Feb 19 16:19:02 computer8 dnsmasq[1506]: setting upstream servers from DBus
Feb 19 16:19:02 computer8 dnsmasq[1506]: using nameserver 208.67.220.220#53
Feb 19 16:19:02 computer8 dnsmasq[1506]: using nameserver 208.67.222.222#53

This is what ifconfig gives me

eth0      Link encap:Ethernet  HWaddr 00:24:21:a0:cf:d0  
      inet addr:192.168.1.108  Bcast:192.168.1.255  Mask:255.255.255.0
      inet6 addr: fe80::224:21ff:fea0:cfd0/64 Scope:Link
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:1039910 errors:0 dropped:0 overruns:0 frame:0
      TX packets:199 errors:0 dropped:47 overruns:0 carrier:0
      collisions:0 txqueuelen:1000 
      RX bytes:68572248 (68.5 MB)  TX bytes:16079 (16.0 KB)

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:176 errors:0 dropped:0 overruns:0 frame:0
      TX packets:176 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:0 
      RX bytes:13122 (13.1 KB)  TX bytes:13122 (13.1 KB)

lxcbr0    Link encap:Ethernet  HWaddr ae:67:41:66:c6:71  
      inet addr:10.0.3.1  Bcast:10.0.3.255  Mask:255.255.255.0
      inet6 addr: fe80::ac67:41ff:fe66:c671/64 Scope:Link
      UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
      RX packets:0 errors:0 dropped:0 overruns:0 frame:0
      TX packets:40 errors:0 dropped:0 overruns:0 carrier:0
      collisions:0 txqueuelen:0 
      RX bytes:0 (0.0 B)  TX bytes:7989 (7.9 KB)
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1 Answer 1

It does sound like the routers are not correctly set up to forward DHCP requests. Could you check the logs to see if the computers even send the requests correctly? (should be visible in Log viewer -> syslog)

share|improve this answer
    
Thanks for your answer. I posted the syslog info. Does that help any? –  Brad Feb 19 '13 at 5:49
    
OK, so you have two interfaces: eth0 (192.168.1.108) which is the ethernet port and lxcbr0 (10.0.3.1) which seems to be some sort of bridging within LXC. I am not familiar with this. Do you know which of these you want to use? –  Magnus Jonsson Feb 19 '13 at 9:21
    
I want to use eth0. I'm not sure why the lxcbr0 is there. –  Brad Feb 19 '13 at 11:12

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