Потеряйте Интернет при соединении с Ethernet-коммутатором Trendnet

Я просто установил Ubuntu 12.10 приблизительно на 30 компьютерах в компьютерной лаборатории средней школы (и удалил Win XP и Win 7). Проблема, которую я имею теперь, состоит в том, что мы не можем получить доступ к Интернету по нашей сети.

Школа имеет маршрутизатор ADSL и единственный кабель Ethernet, который прибывает в компьютерную лабораторию. Этот кабель соединяется с 24 портами Trendnet Ethernet Switch. Половина компьютеров подключена к этому переключателю. Другой кабель Ethernet идет с этого переключателя на идентичный переключатель через лабораторию, дающую доступ в Интернет другой половине компьютеров. Я не настраивал сеть этот путь, но это раньше работало, когда компьютерам загрузили окна на них. После установки человечности у нас больше нет интернет-соединения по сети.

Когда я соединяю кабель Ethernet от маршрутизатора ADSL непосредственно к одному из компьютеров, Интернет работает правильно, но когда я подключаю его к переключателю, мы ничего не получаем. Ubuntu даже не присваивает локальные IP-адреса компьютеру, когда установлено на автоматический DHCP. Я пытался установить ручные IP-адреса вне диапазона DHCP: Я установил IP-адрес на 192.168.1.101 до 192.168.1.130. Я установил шлюз на 192.168.1.1, маску подсети к 255.255.255.0 и маршрутизатор DNS к 192.168.1.1. Я позже переключил маршрутизатор DNS на IP-адреса opendns.

Установка IP-адресов вручную позволяла мне проверять с помощью ping-запросов компьютеры в локальной сети пока на том же переключателе. Это испытало бы таймаут, если бы компьютер был на другом переключателе или если они были вне локальной сети и все еще никакого доступа в Интернет.

Я также пытался перезапустить маршрутизатор и переключатели без удачи.

У кого-либо есть какие-либо предложения о том, как получить доступ к Интернету по нашей локальной сети и как объединить компьютеры в сеть через оба переключателя?

Править:

Вот то, что системный журнал дает мне:

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

Это - то, что ifconfig дает мне

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)