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Centos 6.4 "ping : unknown host google.com"

kucingbelang4kucingbelang4 Member
in Help

Help me, i am newbie in server. I have server with centos 6.4 , lo and eth0 is already up. but it cannot ping to google . setting /etc/resolv.conf nameserver 127.0.0.1 .

please help me. thx before

«1

Comments

  • awsonawson Member

    fix your dns server

  • taronyutaronyu Member

    Change 127.0.0.1 to 8.8.8.8 (public dns by Google)

  • ShardHostSarahShardHostSarah Member
    edited August 2013

    Add the following to resolv.conf

    nameserver 8.8.8.8
    nameserver 8.8.4.4

  • kucingbelang4kucingbelang4 Member
    edited August 2013

    @ShardHost said:
    Add the following to resolv.conf

    nameserver 8.8.8.8
    nameserver 8.8.4.4

    now my /etc/resolv.conf nameserver 8.8.8.8 nameserver 8.8.4.4 , still cannot ping google.com it said "ping: unknown host google.com"

  • kucingbelang4kucingbelang4 Member

    i tried to pinging itself and return "Destination Host Prohibited". what is that??

  • knopix80knopix80 Member

    Is it connected to internet ? Pleease test ping to 8.8.4.4 and 8.8.8.8, what is the result?

  • CasiusCasius Member

    Try restarting your server.

  • knopix80knopix80 Member

    Are u Indonesian ?

  • kucingbelang4kucingbelang4 Member

    @knopix80 said:
    Is it connected to internet ? Pleease test ping to 8.8.4.4 and 8.8.8.8, what is the result?

    yes , when i tried to ping 8.8.4.4 and 8.8.8.8 the result was return nothing (i forced to stop ctrl + z)

  • knopix80knopix80 Member
    edited August 2013

    It seems you should fix the gateway until your box connected to internet.

  • c0yc0y Member

    @kucingbelang4 said:
    i forced to stop ctrl + z

    ^Z doesn't stop it, it moves it to the background (resume using the 'fg' command)

    Use ^C instead (^ = control of course)

  • kucingbelang4kucingbelang4 Member
    edited August 2013

    @knopix80 said:

    It seems you should fix the gateway until your box connected to internet.

    gateway?? am using 192.168.19.1 , and the webserver 192.168.19.20 . can i assign etc/resolv.conf with 192.168.19.1 ??

  • kucingbelang4kucingbelang4 Member

    @knopix80 said:
    Are u Indonesian ?

    yess , sory for my bad english :p

  • knopix80knopix80 Member

    @kucingbelang4 said:
    gateway?? am using 192.168.19.1 , and the webserver 192.168.19.20 . can i assign etc/resolv.conf with 192.168.19.1 ??
    @kucingbelang4 said:
    gateway?? am using 192.168.19.1 , and the webserver 192.168.19.20 . can i assign etc/resolv.conf with 192.168.19.1 ??

    Please do tracert 8.8.4.4

  • kucingbelang4kucingbelang4 Member
    edited August 2013

    @Casius said:
    Try restarting your server.

    am done with restart the server, and still return "
    ping: unknown host google.com" :/

  • kucingbelang4kucingbelang4 Member

    @knopix80 said:
    Please do tracert 8.8.4.4

    am traceroute 8.8.4.4 and return "

    traceroute to 8.8.4.4 (8.8.4.4), 30 hops max, 60 byte packets
    1 192.168.19.1 (192.168.19.1) 0.291 ms 0.461 ms 0.299 ms
    1 192.168.19.1 (192.168.19.1) 0.291 ms 0.461 ms 0.299 ms
    1 192.168.19.1 (192.168.19.1) 0.291 ms 0.461 ms 0.299 ms
    2 * * *
    3 * * *
    4 * * *
    5 * * *
    6 * * *
    ",

    what is that mean??

  • kucingbelang4kucingbelang4 Member

    @Frost said:
    Use ^C instead (^ = control of course)

    i stop it forced because get more than 3 minutes to respond. its timeout right?

  • c0yc0y Member

    @kucingbelang4 said:
    i stop it forced because get more than 3 minutes to respond. its timeout right?

    Ping on linux will keep pinging (or at least attempting) until you kill it or when you specify an amount of pings it should emit (-c flag)

    To see if it's still running, try:

    ps aux | grep ping | grep -v grep

    To get rid of them the easy way is:

    killall ping

    Although one could argue this is a cleaner method in general:

    for x in $(ps aux | grep ping | grep -v grep | awk '{print $2}'); do kill $x; done
  • AdducAdduc Member

    If it's a default install, eth0 isn't setup by default. Even by running ifconfig eth0 up, you'll still have issues. The CentOS FAQ has more info.

    Thanked by 1seriesn
  • kucingbelang4kucingbelang4 Member

    @Adduc said:
    If it's a default install, eth0 isn't setup by default. Even by running ifconfig eth0 up, you'll still have issues. The CentOS FAQ has more info.

    am using minimal install centos 6.4 final

  • kucingbelang4kucingbelang4 Member

    @Frost said:

    for x in $(ps aux | grep ping | grep -v grep | awk '{print $2}'); do kill $x; done

    when i use killall ping, it return "ping: no process killed"

  • prredprred Member

    Is NetworkManager running ? Disabling it might help.

    service NetworkManager stop
chkconfig NetworkManager off
reboot
  • twaintwain Member

    @Frost - pls don't hijack this thread with your fancy commands.

  • DennisdeWitDennisdeWit Member

    To be sure wether you have internet at all, does your internet work correctly?

    route -n

  • kucingbelang4kucingbelang4 Member

    @DennisdeWit said:
    To be sure wether you have internet at all, does your internet work correctly?

    route -n

    when i try route -n , it return "

    Kernel IP routing table
    Destination Gateway Genmask Flags Metric Ref Use Iface
    192.168.19.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
    169.254.0.0 0.0.0.0 255.255.0.0 U 1002 0 0 eth0
    0.0.0.0 192.168.19.1 0.0.0.0 UG 0 0 0 eth0

    ".
    whats that mean?

  • kucingbelang4kucingbelang4 Member
    edited August 2013

    @prred said:
    Is NetworkManager running ? Disabling it might help.

    service NetworkManager stop
chkconfig NetworkManager off
reboot

    why should i disabling it off?

  • AlexBarakovAlexBarakov Patron Provider, Veteran

    What kind of VPS is this? KVM/OpenVZ?

    Are gateways setup properly? Are you using DHCP or manually configuring the network? If you try pinging an ip directly (8.8.8.8) do you get a response?

    To me it sounds like a gateway issue.

  • ErawanArifNugrohoErawanArifNugroho Member

    is this a virtualbox or vmware?

    try to change the network adapter :)

  • MelitaMelita Member, Host Rep
    edited August 2013

    Seems like just a local office computer?

    IP address 192.168.19.20, gateway 192.168.19.1. Please check if there are other windows computer with same network / gateway which can connect to internet. Your LAN router might not passing any traffic at all.

    My other suspicion is this (since you tell about prohibited packet): Would you mind to tell the output of

    iptables -L -n -v

    You can also always try to do

    service iptables stop

    then

    ping 8.8.8.8

    does it works?

    If it's working, just edit /etc/resolv.conf to

    nameserver 8.8.8.8

    nameserver 8.8.4.4

    And it should be able to resolve hostname now.

  • Master_BoMaster_Bo Member

    Let's start with basics. Run

    ifconfig -a

    to show the state of network interfaces. Is eth0/whatever it's called up?

    iptables -L

    will show firewall status.

    cat /etc/resolv.conf

    shows current resolver state (what NS records are available). Note that under normal circumstances you don't have to correct /etc/resolv.conf manually.

    Unless network interface is up and tuned correctly, no external connectivity would occur.

    Advice: when posting file contents/program outputs, add four spaces in front of every line, in order the output was just as programs output them, not concatenated to a single line.

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