$Id: FAQ,v 1.1 2001/06/08 19:58:23 pcharles Exp $

                             jpcap FAQ


  Q. I'm using JDK1.2 and the performance is terrible.

  A. Although the project compiles and runs under JDK1.2, JDK1.3.1 is 
     highly recommended. (1.3.0_02 is ok, but isn't very stable on Linux.) 
     In general, the performance of the 1.3 VM is superior to 1.2.
     The difference is especially noticable in jpcap when using 
     the graphical component of net.sourceforge.jpcap.client.CaptureTool
     to visualize network traffic. The project has also been tested and 
     works with the JDK1.4 beta.


  Q. I'm trying to use jpcap on my Alpha machine, but I can't 
     capture any packets.

  A. There are problems with older versions of libpcap on Alpha.
      On 2.2.5-22 kernel Alpha machine, libpcap-0.4-19 and
      libpcap-0.4-29 distributions packaged by redhat do not work.
      All pcap functions return normally, but after entering 
      pcap_loop(), no packets are ever captured and the handler
      never called back.

      On alpha, upgrade to the latest version of libpcap.
      libpcap-0.6.2-3 (included in RawHide for Alpha distro) 
      is recommended. Try rpmfind.org to locate the latest for 
      your distribution.


  Q. I'm calling PacketCapture.getNetwork() and .getNetmask(), and 
     the methods always return zero or garbage.

  A.  These functions return random values which change with every 
      invocation on some older versions of libpcap, notably 0.4-16 
      included with the tool ethereal.

      Upgrading to libpcap v0.6.2 or later is recommended.

