Lighttpd

Lighty responds with a 404 Bad Request when the virtual host name starts with a number.

diff -ruN lighttpd-1.4.19.orig/src/request.c lighttpd-1.4.19/src/request.c
--- lighttpd-1.4.19.orig/src/request.c  2008-06-19 06:30:05.000000000 +0200
+++ lighttpd-1.4.19/src/request.c       2008-06-19 06:30:33.000000000 +0200
@@ -125,7 +125,7 @@
                                }
                        } else if (i == 0) {
                                /* the first character of the hostname */
-                               if (!light_isalpha(c)) {
+                               if (!light_isalnum(c)) {
                                        return -1;
                                }
                                label_len++;

This bug was originally reported at
http://bugs.gentoo.org/show_bug.cgi?id=228281

Arthur Hagen states on that bug:

If following the RFCs strictly, a host name can not start with a number.

Quoting RFC952:
<name> ::= <let>[*[<let-or-digit-or-hyphen>]<let-or-digit>]

However, after someone (by mistake) assigned 3com the domain name 3com.com some
twenty-odd years ago, the practice has been to allow it even though it's
technically wrong (cf. Mockapetris et al.)

In other words, yeah, this should be fixed despite being "correct".