My next question:
What exactly is an HTTP/S server -- apparently it is a requirement for
browser administration access to a Xen-based system? Is Apache such a
server and if not can it be turned into such a server???
  

HTTPS?  It's a secured version of HTTP.  I don't think you shouldn't need to install anything extra to make this work - Twisted includes its own HTTP server.

(btw, Apache can serve over HTTPS but we don't use it in Xen)
 

netstat -anp  excerpt of Xen 2.0.4 on CentOS 3.4:

 tcp        0      0 0.0.0.0:8000                0.0.0.0:*                   LISTEN      17856/python        tcp        0      0 0.0.0.0:8001                0.0.0.0:*                   LISTEN      17856/python        tcp        0      0 0.0.0.0:8002                0.0.0.0:*                   LISTEN      17855/xfrd          tcp        0      0 0.0.0.0:8080                0.0.0.0:*                   LISTEN      17977/python      
User manual says this can be configured via /usr/lib/python2.3/site-packages/xen/sv/params.py. This file does not exist in the /usr/lib/python*, but /etc/xen/xend-config.sxp includes:

 # Port xend should use for the HTTP interface.
 (xend-port         8000)

Questions:

1) xend web interface appears on port 8080 (non SSL).  Is the xend-config.sxp parameter not honored?

2) Does Twisted natively support SSL? I found conflicting statements in my brief research.

3) What is listening on ports 8000 and 8001?

4) Related subject, how is xfrd (port 8002) secured against malicious domain transfers?


Rich