Django getting lots of SuspiciousOperation: Invalid HTTP_HOST header

Django getting lots of SuspiciousOperation: Invalid HTTP_HOST header

I'm using Django 1.5, Apache, mod_wsgi and python 2.7, debian hosted on
linode.
Since I upgraded from django 1.3 to django 1.5, I started receive some
error messages, for example: "ERROR (EXTERNAL IP): Internal Server Error:
/feed/". With this traceback:
Traceback (most recent call last):
File
"/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py",
line 92, in get_response
response = middleware_method(request)
File
"/usr/local/lib/python2.7/dist-packages/django/middleware/common.py",
line 57, in process_request
host = request.get_host()
File "/usr/local/lib/python2.7/dist-packages/django/http/request.py",
line 72, in get_host
"Invalid HTTP_HOST header (you may need to set ALLOWED_HOSTS): %s" %
host)
SuspiciousOperation: Invalid HTTP_HOST header (you may need to set
ALLOWED_HOSTS): tadjenanet.montadamoslim.com
But, a few days ago, the volume of this errors increased greatly, and for
a lot of url's that I don't even have in my website.
I saw the answers here(Django's SuspiciousOperation Invalid HTTP_HOST
header) and I understand why I'm getting this, but I need to know how to
avoid this increasing my server security.