System registration fails with "Name or service not known"

Solution Verified - Updated -

Environment

  • Red Hat Network(RHN)
  • Red Hat Enterprise Linux(RHEL)
  • Red Hat subscription Manager(RHSM)

Issue

  • System registration fails with error Name or service not known :

    Error communicating with server. The message was:
Name or service not known

  • Unable to register system its fails error gaierror: [Errno -2] Name or service not known :

    2014-06-18 14:33:50,133 [ERROR]  @managercli.py:151 - Error during registration: [Errno -2] Name or service not known
2014-06-18 14:33:50,134 [ERROR]  @managercli.py:152 - [Errno -2] Name or service not known
Traceback (most recent call last):
  File "/usr/share/rhsm/subscription_manager/managercli.py", line 1045, in _do_command
    owner_key = self._determine_owner_key(admin_cp)
  File "/usr/share/rhsm/subscription_manager/managercli.py", line 1148, in _determine_owner_key
    owners = cp.getOwnerList(self.username)
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 852, in getOwnerList
    return self.conn.request_get(method)
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 541, in request_get
    return self._request("GET", method)
  File "/usr/lib64/python2.6/site-packages/rhsm/connection.py", line 448, in _request
    conn.request(request_type, handler, body=body, headers=headers)
  File "/usr/lib64/python2.6/httplib.py", line 914, in request
    self._send_request(method, url, body, headers)
  File "/usr/lib64/python2.6/httplib.py", line 951, in _send_request
    self.endheaders()
  File "/usr/lib64/python2.6/httplib.py", line 908, in endheaders
    self._send_output()
  File "/usr/lib64/python2.6/httplib.py", line 780, in _send_output
    self.send(msg)
  File "/usr/lib64/python2.6/httplib.py", line 739, in send
    self.connect()
  File "/usr/lib64/python2.6/site-packages/M2Crypto/httpslib.py", line 51, in connect
    socket.getaddrinfo(self.host, self.port, 0, socket.SOCK_STREAM):
gaierror: [Errno -2] Name or service not known

  • yum update fails with Error communicating with server. The message was Name or service unknown

Resolution

  • Start the messagebus and haldaemon services, if not running.

  • Check /etc/resolv.conf file to see if the DNS server entry is present in this file. If not, then verify your DNS server and then add its entry.

    # vi /etc/resolv.conf

nameserver <dns_server_ip>

  • Check if sslCACert is define properly in /etc/sysconfig/rhn/up2date
    It should be:

      sslCACert=/usr/share/rhn/RHNS-CA-CERT

  • Restart network service:

    # service network restart

For a system registered with RHSM:

  • Correct Server hostname and Server prefix entries in /etc/rhsm/rhsm.conf file as below:

    [server]
# Server hostname:
hostname = subscription.rhn.redhat.com

# Server prefix:
prefix = /subscription

  • Now register system

For a system registered with Satellite/Capsule:

  • Set the correct Satellite hostname in Capsule /etc/hosts file.

Root Cause

  • Firewall blocking some ports.
  • Incorrect CA certificate in /etc/sysconfig/rhn/up2date
    For system registered using RHN Classic, value is "sslCACert=/usr/share/rhn/RHNS-CA-CERT"
  • Incorrect Server hostname and Server prefix entries in /etc/rhsm/rhsm.conf file.

Diagnostic Steps

  • From error message it seems that there is an issue with name resolution.

  • Check whether inbound and outbound ports i.e. 443 and 80 are open.

  • To check communication between client and server,

    # telnet xmlrpc.rhn.redhat.com 80
# telnet xmlrpc.rhn.redhat.com 443
# nc -z rhn.redhat.com 80 -Xconnect
# nc -z rhn.redhat.com 443 -Xconnect
# echo -e "TRACE / HTTP/1.1\nHost: xmlrpc.rhn.redhat.com\n\n" | nc xmlrpc.rhn.redhat.com 80

  • Check whether messagebus and haldaemon services are running:

    # /etc/init.d/messagebus status
# /etc/init.d/haldaemon status

For system registered with Red Hat Subscription Manager

  • Check /etc/rhsm/rhsm.conf file to verify following entries :

    [server]
# Server hostname:
hostname = subscription.rhn.redhat.com

# Server prefix:
prefix = /subscription

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