Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: ping -c 2 8.8.8.8 connect: Network is unreachable

  1. #1
    Join Date
    Sep 2020
    Beans
    4

    ping -c 2 8.8.8.8 connect: Network is unreachable

    I need a same problem with my ubuntu configs

    Can help me ?

    Code:
    root@srv00:~# sudo /etc/init.d/networking restart && sudo dhclient
    [ ok ] Restarting networking (via systemctl): networking.service.
    root@srv00:~# ping -c 2 8.8.8.8
    connect: Network is unreachable
    root@srv00:~# uname -a
    Linux srv00 4.15.0-117-generic #118-Ubuntu SMP Fri Sep 4 20:02:41 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
    root@srv00:~# cat /etc/hosts
    127.0.0.1 localhost
    #10.0.0.8 localhost
    127.0.1.1 srv00
    
    
    # The following lines are desirable for IPv6 capable hosts
    ::1     ip6-localhost ip6-loopback
    fe00::0 ip6-localnet
    ff00::0 ip6-mcastprefix
    ff02::1 ip6-allnodes
    ff02::2 ip6-allrouters
    root@srv00:~# cat /hosts
    cat: /hosts: No such file or directory
    root@srv00:~# cat /etc/hosts
    127.0.0.1 localhost
    #10.0.0.8 localhost
    127.0.1.1 srv00
    
    
    # The following lines are desirable for IPv6 capable hosts
    ::1     ip6-localhost ip6-loopback
    fe00::0 ip6-localnet
    ff00::0 ip6-mcastprefix
    ff02::1 ip6-allnodes
    ff02::2 ip6-allrouters
    root@srv00:~# ifconfig -a
    docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
            inet 172.17.0.1  netmask 255.255.0.0  broadcast 172.17.255.255
            ether 02:42:d2:de:b4:a8  txqueuelen 0  (Ethernet)
            RX packets 0  bytes 0 (0.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 0  bytes 0 (0.0 B)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    
    enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet6 fe80::a00:27ff:fe85:ffbd  prefixlen 64  scopeid 0x20<link>
            ether 08:00:27:85:ff:bd  txqueuelen 1000  (Ethernet)
            RX packets 0  bytes 0 (0.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 141  bytes 43718 (43.7 KB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
            device interrupt 19  base 0xd020
    
    
    enp0s8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.0.125  netmask 255.255.255.0  broadcast 192.168.0.255
            inet6 fe80::a00:27ff:fe47:71be  prefixlen 64  scopeid 0x20<link>
            inet6 2804:5500:0:8401:a00:27ff:fe47:71be  prefixlen 64  scopeid 0x0<global>
            ether 08:00:27:47:71:be  txqueuelen 1000  (Ethernet)
            RX packets 1557  bytes 196338 (196.3 KB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 1244  bytes 192594 (192.5 KB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
            device interrupt 16  base 0xd240
    
    
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 12  bytes 720 (720.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 12  bytes 720 (720.0 B)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    
    root@srv00:~#
    Last edited by ajgreeny; September 16th, 2020 at 04:39 PM. Reason: code tags

  2. #2
    Join Date
    Mar 2010
    Location
    Squidbilly-Land
    Beans
    21,341
    Distro
    Ubuntu Mate 16.04 Xenial Xerus

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    I can't help at all with docker, but for normal ubuntu servers, please follow these troubleshooting steps, in order.
    https://blog.jdpfu.com/2013/03/01/li...101-networking

    My first guesses are that either
    • a routing problem,
    • firewall problem, or
    • driver problem.

    Could be a HW issue too. Can it ping anything else on the LAN?

    That's why troubleshooting steps should be done in order.
    Last edited by TheFu; September 16th, 2020 at 08:38 PM. Reason: bullet points, not code tags.

  3. #3
    Join Date
    Nov 2008
    Location
    Metro Boston
    Beans
    15,293
    Distro
    Kubuntu 20.04 Focal Fossa

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    Install traceroute from the repositories. It will show every step along the way between you and 8.8.8.8.

    Code:
    $ traceroute 8.8.8.8
    traceroute to 8.8.8.8 (8.8.8.8), 64 hops max
      1   192.168.100.1  0.520ms  0.387ms  0.380ms 
      2   10.16.144.1  7.433ms  7.926ms  8.568ms 
      3   146.115.22.197  9.605ms  9.285ms  11.257ms 
      4   207.172.18.97  17.750ms  17.335ms  19.046ms 
      5   207.172.19.76  18.634ms  17.730ms  18.568ms 
      6   207.172.19.94  16.642ms  16.666ms  16.504ms 
      7   72.14.219.192  16.955ms  15.984ms  16.560ms 
      8   108.170.248.97  15.653ms  16.049ms  15.869ms 
      9   8.8.8.8  16.822ms  17.470ms  16.826ms
    If you ask for help, do not abandon your request. Please have the courtesy to check for responses and thank the people who helped you.

    Blog · Linode System Administration Guides · Android Apps for Ubuntu Users

  4. #4
    Join Date
    Nov 2007
    Location
    London, England
    Beans
    7,080
    Distro
    Xubuntu 20.04 Focal Fossa

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    Can you post the result of these commands:
    Code:
    ip address
    ip route
    ip route get 8.8.8.8
    ip neighbor

  5. #5
    Join Date
    Sep 2020
    Beans
    4

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    root@srv00:~# traceroute 8.8.8.8
    traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 60 byte packets
    1 192.168.0.1 (192.168.0.1) 8.288 ms 8.262 ms 9.421 ms
    2 10.100.100.1 (10.100.100.1) 9.897 ms 9.527 ms 9.478 ms
    3 9.164.165.45.fiberfamily.com.br (45.165.164.9) 9.260 ms 9.222 ms 11.077 ms
    4 170-246-215-241.redebandalarga.net.br (170.246.215.241) 11.365 ms 11.351 ms 11.336 ms
    5 as15169.saopaulo.sp.ix.br (187.16.218.58) 11.853 ms 11.743 ms 10.723 ms
    6 108.170.245.129 (108.170.245.129) 10.737 ms 4.432 ms 74.125.243.1 (74.125.243.1) 4.010 ms
    7 209.85.248.167 (209.85.248.167) 6.485 ms 209.85.250.51 (209.85.250.51) 7.480 ms 72.14.239.25 (72.14.239.25) 6.048 ms
    8 dns.google (8.8.8.8) 5.984 ms 6.141 ms 5.920 ms
    root@srv00:~# ping www.uol.com.br
    PING http://www.uol.com.br(2600:9000:214e...5a19:8b40:93a1 (2600:9000:214e:aa00:1:5a19:8b40:93a1)) 56 data bytes
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=1 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=2 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=3 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=4 Destination unreachable: No route
    ^C

  6. #6
    Join Date
    Sep 2020
    Beans
    4

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    root@srv00:~# ip address
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
    valid_lft forever preferred_lft forever
    2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 1000
    link/ether 08:00:27:85:ff:bd brd ff:ff:ff:ff:ff:ff
    inet6 fe80::a00:27ff:fe85:ffbd/64 scope link
    valid_lft forever preferred_lft forever
    3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UNKNOWN group default qlen 1000
    link/ether 08:00:27:47:71:be brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.125/24 brd 192.168.0.255 scope global enp0s8
    valid_lft forever preferred_lft forever
    inet 192.168.0.128/24 brd 192.168.0.255 scope global secondary enp0s8
    valid_lft forever preferred_lft forever
    inet 192.168.0.105/24 brd 192.168.0.255 scope global secondary dynamic enp0s8
    valid_lft 23558sec preferred_lft 23558sec
    inet6 2804:5500:0:8401:a00:27ff:fe47:71be/64 scope global dynamic mngtmpaddr noprefixroute
    valid_lft 295sec preferred_lft 115sec
    inet6 fe80::a00:27ff:fe47:71be/64 scope link
    valid_lft forever preferred_lft forever
    4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:d2:de:b4:a8 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
    valid_lft forever preferred_lft forever
    root@srv00:~# ip route
    default via 192.168.0.1 dev enp0s8
    default via 192.168.0.1 dev enp0s8 proto dhcp src 192.168.0.105 metric 100
    172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
    192.168.0.0/24 dev enp0s8 proto kernel scope link src 192.168.0.125
    192.168.0.1 dev enp0s8 proto dhcp scope link src 192.168.0.105 metric 100
    root@srv00:~# ip route get 8.8.8.8
    8.8.8.8 via 192.168.0.1 dev enp0s8 src 192.168.0.125 uid 0
    cache
    root@srv00:~# ip neighbor
    192.168.0.113 dev enp0s8 lladdr f8:da:0c:23:e8:d1 REACHABLE
    192.168.0.1 dev enp0s8 lladdr b0:be:76:33:bc:09 REACHABLE
    fe80::8432:9591:20a:9a21 dev enp0s8 lladdr f8:da:0c:23:e8:d1 router STALE
    2804:5500:0:8401:fd73:5f84:1bee:4e88 dev enp0s8 lladdr f8:da:0c:23:e8:d1 router STALE
    fe80::b2be:76ff:fe33:bc09 dev enp0s8 lladdr b0:be:76:33:bc:09 router STALE
    root@srv00:~#

  7. #7
    Join Date
    Mar 2010
    Location
    Squidbilly-Land
    Beans
    21,341
    Distro
    Ubuntu Mate 16.04 Xenial Xerus

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    IPv6 is being used. I find it easier to just disable it completely, but that isn't an option for everyone.
    sudoedit /etc/default/grub
    Modify the line as follows:
    Code:
    GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 quiet splash"
    sudo update-grub
    and reboot the system.
    That should disable IPv6 on the box, completely.


    And please, please, please, please, please, please, please, please use code tags whenever posting terminal output.

  8. #8
    Join Date
    Sep 2020
    Beans
    4

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    --- www.uol.com.br ping statistics ---
    15 packets transmitted, 0 received, +15 errors, 100% packet loss, time 14035ms


    root@srv00:~# sudo update-grub
    Sourcing file `/etc/default/grub'
    Generating grub configuration file ...
    Found linux image: /boot/vmlinuz-4.15.0-117-generic
    Found initrd image: /boot/initrd.img-4.15.0-117-generic
    Found linux image: /boot/vmlinuz-4.15.0-109-generic
    Found initrd image: /boot/initrd.img-4.15.0-109-generic
    done
    root@srv00:~# ping www.uol.com.br
    PING http://www.uol.com.br(2600:9000:214e...5a19:8b40:93a1 (2600:9000:214e:5400:1:5a19:8b40:93a1)) 56 data bytes
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=1 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=2 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=3 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=4 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=5 Destination unreachable: No route
    From 2804:5500:ffff:ffff::2 (2804:5500:ffff:ffff::2) icmp_seq=6 Destination unreachable: No route
    ^C
    --- www.uol.com.br ping statistics ---
    6 packets transmitted, 0 received, +6 errors, 100% packet loss, time 5013ms


    root@srv00:~#

  9. #9
    Join Date
    Mar 2010
    Location
    Squidbilly-Land
    Beans
    21,341
    Distro
    Ubuntu Mate 16.04 Xenial Xerus

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    Please prove/confirm that /etc/default/grub was modified and that you rebooted the system.

    BTW, ping with only IPv4 should look like this:
    Code:
    $ ping www.uol.com.br 
    PING dftex7xfha8fh.cloudfront.net (13.249.123.45) 56(84) bytes of data.
    64 bytes from server-13-249-123-45.atl51.r.cloudfront.net (13.249.123.45): icmp_seq=1 ttl=243 time=14.4 ms
    64 bytes from server-13-249-123-45.atl51.r.cloudfront.net (13.249.123.45): icmp_seq=2 ttl=243 time=16.4 ms

  10. #10
    Join Date
    Nov 2008
    Location
    Metro Boston
    Beans
    15,293
    Distro
    Kubuntu 20.04 Focal Fossa

    Re: ping -c 2 8.8.8.8 connect: Network is unreachable

    I usually disable IPv6 in /etc/sysctl.conf.

    Code:
    net.ipv6.conf.all.disable_ipv6 = 1
    net.ipv6.conf.default.disable_ipv6 = 1
    This works on an ancient CentOS 6.10 machine. But the directory structure under /proc/sys/net/ipv6/conf on my 20.04 machine is the same. So I'd guess adding these two lines to /etc/sysctl.conf and rebooting will also do the trick.
    If you ask for help, do not abandon your request. Please have the courtesy to check for responses and thank the people who helped you.

    Blog · Linode System Administration Guides · Android Apps for Ubuntu Users

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •