100 lines
6.0 KiB
HTML
100 lines
6.0 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<meta name="DC.Type" content="task" />
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<meta name="DC.Title" content="Ping the loopback interface on your server" />
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<meta name="abstract" content="Ping the loopback interface to verify that your TCP/IP software is installed, started, and working properly." />
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<meta name="description" content="Ping the loopback interface to verify that your TCP/IP software is installed, started, and working properly." />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1997, 2006" />
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<meta name="DC.Identifier" content="pingloopback" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>Ping the loopback interface on your server</title>
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</head>
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<body id="pingloopback"><a name="pingloopback"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Ping the loopback interface on your server</h1>
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<div><p>Ping the loopback interface to verify that your TCP/IP software
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is installed, started, and working properly. </p>
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<div class="section"><p>You can perform the test without being connected to a physical
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line or network.</p>
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<p>i5/OS™ reserves the IP address 127.0.0.1,
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the host name LOOPBACK, and the line description value of *LOOPBACK for verifying
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the software. Similarly for IPv6, i5/OS reserves the IP address ::1 and the
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line description <span>*LOOPBACK</span> for this purpose. The IPv6
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loopback interface does not have a corresponding host name because the local
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host tables do not currently support IPv6 addresses. However, you can use
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a Domain Name System (DNS) to store the IPv6 host name instead of using the
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local host table.</p>
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<p>To ping the loopback interface on your server to troubleshoot
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the problem, follow these steps:</p>
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</div>
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<ol><li class="stepexpand"><span>At the command line, type these commands:</span><ul><li>For IPv4: <samp class="codeph">PING '127.0.0.1'</samp> or <samp class="codeph">PING LOOPBACK</samp></li>
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<li>For IPv6: <samp class="codeph">PING '::1'</samp></li>
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</ul>
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See Ping parameters to fine-tune the Ping command to get the most accurate
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results. Prompt on the Ping command by selecting F4 for complete details on
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the Ping parameters.</li>
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<li class="stepexpand"><span>Failures might indicate the following problems.</span>
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<table border="1" frame="hsides" rules="rows" cellpadding="4" cellspacing="0" summary="" class="choicetableborder">
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<thead><tr><th valign="bottom" align="left" id="d0e51-option">Problem</th>
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<th valign="bottom" align="left" id="d0e51-desc">Recovery</th></tr></thead>
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<tbody><tr><td valign="top" headers="d0e51-option" id="d0e58"><strong>The local host table does not have an entry for the IPv4
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LOOPBACK host name and IP address of 127.0.0.1.</strong></td>
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<td valign="top" headers="d0e51-desc d0e58"><p>You need
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to add the entry to the host table. This is only relevant for IPv4 because
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host tables do not currently support IPv6. To verify the host table entries,
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follow these steps:</p>
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<ol type="a"><li>At the command line, type <samp class="codeph">CFGTCP</samp> (Configure TCP/IP).</li>
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<li>Select option 10 (Work with TCP/IP Host Table Entries).</li>
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<li>Verify that the host table contains an entry for the LOOPBACK host name
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and IP address 127.0.0.1.</li>
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</ol>
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</td>
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</tr>
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<tr><td valign="top" headers="d0e51-option" id="d0e74"><strong>The loopback interface is not active.</strong></td>
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<td valign="top" headers="d0e51-desc d0e74"><p>To
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activate the loopback interface: </p>
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<ol type="a"><li>At the command line, type <samp class="codeph">NETSTAT</samp>.</li>
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<li>Select option 1 (Work with TCP/IP interface status) for IPv4 interfaces,
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or select option 4 (Work with IPv6 interface status) for IPv6 interfaces.</li>
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<li>Scroll down to find the loopback interface (127.0.0.1 or ::1), and select
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option 9 (Start) from the Work with TCP/IP interface status menu.</li>
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</ol>
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</td>
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</tr>
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<tr><td valign="top" headers="d0e51-option" id="d0e90"><strong>TCP/IP has not been started.</strong></td>
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<td valign="top" headers="d0e51-desc d0e90">To start TCP/IP,
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type <samp class="codeph">STRTCP</samp> (Start TCP/IP) at the command line.</td>
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</tr>
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</tbody></table>
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</li>
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</ol>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzakupingcharbased.htm" title="You can use the PING command from the character-based interface to test your TCP/IP connectivity.">Ping from a character-based interface</a></div>
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</div>
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<div class="relref"><strong>Related reference</strong><br />
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<div><a href="rzakupingerrors.htm" title="Use these common error messages to find out how to resolve the errors.">Common error messages</a></div>
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<div><a href="rzakupingparam.htm" title="Ping parameters enable you to adjust the way the Ping command performs its test of connectivity.">Ping parameters</a></div>
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</div>
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</div>
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</body>
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</html>
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