tests: update README about servers and port numbers

Closes #7242

diff --git a/tests/README.md b/tests/README.md
index 3ecfb4ac07db02b0efbc03e5a973828d0460d7f7..db884a2bea509f292da166b01d4944ed5f35865c 100644 (file)
--- a/tests/README.md
+++ b/tests/README.md
@@ -51,17 +51,15 @@
 
 ### Test servers
 
-  The test suite runs simple FTP, POP3, IMAP, SMTP, HTTP and TFTP stand-alone
-  servers on the ports listed above to which it makes requests. For SSL tests,
-  it runs stunnel to handle encryption to the regular servers. For SSH, it
-  runs a standard OpenSSH server. For SOCKS4/5 tests SSH is used to perform
-  the SOCKS functionality and requires a SSH client and server.
-
-  The base port number (8990), which all the individual port numbers are
-  indexed from, can be set explicitly using runtests.pl' -b option to allow
-  running more than one instance of the test suite simultaneously on one
-  machine, or just move the servers in case you have local services on any of
-  those ports.
+  The test suite runs stand-alone servers on random ports to which it makes
+  requests. For SSL tests, it runs stunnel to handle encryption to the regular
+  servers. For SSH, it runs a standard OpenSSH server. For SOCKS4/5 tests SSH
+  is used to perform the SOCKS functionality and requires a SSH client and
+  server.
+
+  The listen port numbers for the test servers are picked randomly to allow
+  users to run multiple test cases concurrently and to not collide with other
+  existing services that might listen to ports on the machine.
 
   The HTTP server supports listening on a Unix domain socket, the default
   location is 'http.sock'.
@@ -87,6 +85,8 @@
   line). The latter is meant for local temporary disables and will be ignored
   by git.
 
+  Test cases mentioned in `DISABLED` can still be run if `-f` is provided.
+
   When `-s` is not present, each successful test will display on one line the
   test number and description and on the next line a set of flags, the test
   result, current test sequence, total number of tests to be run and an