<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML ><HEAD ><TITLE >Testing internal MASQ client to MASQ server connectivity</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Linux IP Masquerade HOWTO" HREF="index.html"><LINK REL="UP" TITLE="Testing IP Masquerade " HREF="testing.html"><LINK REL="PREVIOUS" TITLE="Testing internal MASQ client PC connectivity" HREF="testing-the-masqed-pc.html"><LINK REL="NEXT" TITLE="Testing internal MASQ server connectivity" HREF="testing-masq-server-internal.html"></HEAD ><BODY CLASS="SECT1" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Linux IP Masquerade HOWTO</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="testing-the-masqed-pc.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" >Chapter 5. Testing IP Masquerade</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="testing-masq-server-internal.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="TESTING-MASQED-PC-TO-MASQ-SERVER" ></A >5.3. Testing internal MASQ client to MASQ server connectivity</H1 ><P ><P ></P ><UL ><LI ><P ><STRONG >Step Three: Testing internal MASQ client to MASQ server connectivity</STRONG > </P ><P >Next, from the same internal MASQed computer, try pinging the the IP address of the Linux MASQ server's INTERNAL interface (i.e. <STRONG >ping 192.168.0.1 </STRONG >). This will verify that TCP/IP is correctly working on both the local and Linux MASQ machine. Almost ALL modern operating systems have built-in support for the "ping" command. If this ping doesn't work, make sure that TCP/IP is correctly configured on the MASQed Server as described by the various Network HOWTOs (URLs can be found in the requirements section for your 2.4.x kernel in <A HREF="kernel-2.4.x-requirements.html" >Section 2.6</A >, 2.2.x kernel in <A HREF="kernel-2.2.x-requirements.html" >Section 2.7</A >, or 2.0.x kernel in <A HREF="kernel-2.0.x-requirements.html" >Section 2.8</A >). The output should look something like the following (hit Control-C to abort the ping):</P ><P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" WIDTH="90%" ><TR ><TD ><FONT COLOR="#000000" ><PRE CLASS="PROGRAMLISTING" >------------------------------------ masq-client# ping 192.168.0.1 PING 192.168.0.1 (192.168.0.1): 56 data bytes 64 bytes from 192.168.0.1: icmp_seq=0 ttl=255 time=0.8 ms 64 bytes from 192.168.0.1: icmp_seq=1 ttl=255 time=0.4 ms 64 bytes from 192.168.0.1: icmp_seq=2 ttl=255 time=0.4 ms 64 bytes from 192.168.0.1: icmp_seq=3 ttl=255 time=0.5 ms ^C --- 192.168.0.1 ping statistics --- 4 packets transmitted, 4 packets received, 0% packet loss round-trip min/avg/max = 0.4/0.5/0.8 ms ------------------------------------</PRE ></FONT ></TD ></TR ></TABLE ></P ><P >If the ping failed, check the network connection between the MASQ server and the PC. If it's a DIRECT Ethernet connection (no hub or switch), you MUST have a "Ethernet cross-over cable". These cables are common and can be found at any computer store. Without this cable, the NICs (network cards) will not give you a "LINK" light. If you are using a hub or switch, make sure the ports connected to the MASQ server and MASQed client machine have a LINK light. If they do and the pings STILL don't work or there is a lot of packet loss, try different ports on the hub/switch (it not all that uncommon to have hub/switch ports die). Finally, if things still don't work perfectly, try replacing each of the NICs in the machines. You would be surprised how many people I've helped have found that their NIC cards were going bad and caused them all kinds of grief.</P ></LI ></UL > </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="testing-the-masqed-pc.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="testing-masq-server-internal.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Testing internal MASQ client PC connectivity</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="testing.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Testing internal MASQ server connectivity</TD ></TR ></TABLE ></DIV ></BODY ></HTML >