Bug 3301: Update CONNECT_FAIL message to mention DNS and connectivity issues

diff --git a/errors/templates/ERR_CANNOT_FORWARD b/errors/templates/ERR_CANNOT_FORWARD
index 7e7a7a45185747a395ccd5739ed9738eeca90363..6abe3ce1a58385724621fafe3abe9af1124ce4ec 100644 (file)
--- a/errors/templates/ERR_CANNOT_FORWARD
+++ b/errors/templates/ERR_CANNOT_FORWARD
@@ -23,7 +23,15 @@ body
 <p><b>Unable to forward this request at this time.</b></p>
 </blockquote>
 
-<p>This request could not be forwarded to the origin server or to any parent caches. The most likely cause for this error is that the cache administrator does not allow this cache to make direct connections to origin servers, and all configured parent caches are currently unreachable.</p>
+<p>This request could not be forwarded to the origin server or to any parent caches.</p>
+
+<p>Some possible problems are:</p>
+<ul>
+<li id="missing-dns">The domain name <q>%H</q> might not be found in DNS.</li>
+<li id="network-down">An Internet connection needed to access this domains origin servers may be down.</li>
+<li id="no-peer">All configured parent caches may be currently unreachable.</li>
+<li id="permission-denied">The administrator may not allow this cache to make direct connections to origin servers.</li>
+</ul>
 
 <p>Your cache administrator is <a href="mailto:%w%W">%w</a>.</p>