“host not found” on nxclient connect to nxserver

Cause: my user couldn’t read /etc/hosts

This entry was posted on Friday, April 9th, 2010 at 8:51 am and is filed under Linux. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

One Response to ““host not found” on nxclient connect to nxserver”

  1. Mladen says:
    February 16, 2012 at 6:57 pm

    I like this posting because its nice and simple, so responding to it.

    Indeed, users should have read permissions on /etc/hosts. This is typical:

    ls -l /etc/hosts
    -rw-r–r– 1 root root 386 2012-02-16 13:44 /etc/hosts

    But that may not be the real problem.

    If on the server running the nxserver can not ping localhost like this:

    ping localhost
    PING localhost.localdomain (127.0.0.1) 56(84) bytes of data.
    64 bytes from localhost.localdomain (127.0.0.1): icmp_req=1 ttl=64 time=0.018 ms
    64 bytes from localhost.localdomain (127.0.0.1): icmp_req=2 ttl=64 time=0.015 ms

    Instead you get something like this:

    ping localhost
    ping: unknown host localhost

    Then something is not right with your DNS lookup methods.

    First, verify that the following line exists in /etc/hosts:

    127.0.0.1 localhost.localdomain localhost

    Next, check your /etc/host.conf, it should have this:

    order hosts,bind
    multi on

    What this means is that for DNS lookups, you should first read the /etc/hosts file before “bind” — which is DNS.. HOWEVER, this is an old way of doing DNS lookups, so there is one more place to checK;

    /etc/nsswitch.conf

    If you have something similar to the following line, it will NOT work:

    hosts: mdns4_minimal [NOTFOUND=return] dns mdns4

    Instead, add “files” at the beginning of the value:

    hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4

    Now check that “ping localhost” works.

    Finally, if it still isn’t working, verify your routing table:

    netstat -rn
    Kernel IP routing table
    Destination Gateway Genmask Flags MSS Window irtt Iface
    0.0.0.0 9.26.118.1 0.0.0.0 UG 0 0 0 eth0
    9.26.118.0 0.0.0.0 255.255.254.0 U 0 0 0 eth0
    127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo
    169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0

    If you do NOT have the 127.0.0.0 line for “lo”, then you should add it:

    route add -net 127.0.0.0 netmask 255.0.0.0 dev lo

    Hope this also helps.

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