diff --git a/ChangeLog b/ChangeLog
index 92eb0825..cf38cbf5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -67,6 +67,7 @@ ver. 0.9.2 (2014/XX/XXX) - wanna-be-released
    * action.d/{sendmail-*,xarf-login-attack}.conf - report local
      timezone not UTC time/zone. Closes gh-911
    * Conditionally log Ignore IP with reason (dns, ip, command). Closes gh-916
+   * Absorbed DNSUtils.cidr into addr2bin in filter.py, added unittests
 
 
 ver. 0.9.1 (2014/10/29) - better, faster, stronger
diff --git a/fail2ban/server/filter.py b/fail2ban/server/filter.py
index 8b1642b4..12379cd0 100644
--- a/fail2ban/server/filter.py
+++ b/fail2ban/server/filter.py
@@ -367,8 +367,8 @@ class Filter(JailThread):
 					"(?<=b)1+", bin(DNSUtils.addr2bin(s[1]))).group())
 			s[1] = long(s[1])
 			try:
-				a = DNSUtils.cidr(s[0], s[1])
-				b = DNSUtils.cidr(ip, s[1])
+				a = DNSUtils.addr2bin(s[0], cidr=s[1])
+				b = DNSUtils.addr2bin(ip, cidr=s[1])
 			except Exception:
 				# Check if IP in DNS
 				ips = DNSUtils.dnsToIp(i)
@@ -913,22 +913,18 @@ class DNSUtils:
 		return ipList
 
 	@staticmethod
-	def cidr(i, n):
-		""" Convert an IP address string with a CIDR mask into a 32-bit
-			integer.
+	def addr2bin(ipstring, cidr=None):
+		""" Convert a string IPv4 address into binary form.
+		If cidr is supplied, return the network address for the given block
 		"""
-		# 32-bit IPv4 address mask
-		MASK = 0xFFFFFFFFL
-		return ~(MASK >> n) & MASK & DNSUtils.addr2bin(i)
+		if cidr is None:
+			return struct.unpack("!L", socket.inet_aton(ipstring))[0]
+		else:
+			MASK = 0xFFFFFFFFL
+			return ~(MASK >> cidr) & MASK & DNSUtils.addr2bin(ipstring)
 
 	@staticmethod
-	def addr2bin(string):
-		""" Convert a string IPv4 address into an unsigned integer.
+	def bin2addr(ipbin):
+		""" Convert a binary IPv4 address into string n.n.n.n form.
 		"""
-		return struct.unpack("!L", socket.inet_aton(string))[0]
-
-	@staticmethod
-	def bin2addr(addr):
-		""" Convert a numeric IPv4 address into string n.n.n.n form.
-		"""
-		return socket.inet_ntoa(struct.pack("!L", addr))
+		return socket.inet_ntoa(struct.pack("!L", ipbin))
diff --git a/fail2ban/tests/filtertestcase.py b/fail2ban/tests/filtertestcase.py
index 812a02cf..8fa13dfa 100644
--- a/fail2ban/tests/filtertestcase.py
+++ b/fail2ban/tests/filtertestcase.py
@@ -1026,6 +1026,22 @@ class DNSUtilsTests(unittest.TestCase):
 		res = DNSUtils.ipToName('10.0.0.0')
 		self.assertEqual(res, None)
 
+	def testAddr2bin(self):
+		res = DNSUtils.addr2bin('10.0.0.0')
+		self.assertEqual(res, 167772160L)
+		res = DNSUtils.addr2bin('10.0.0.0', cidr=None)
+		self.assertEqual(res, 167772160L)
+		res = DNSUtils.addr2bin('10.0.0.0', cidr=32L)
+		self.assertEqual(res, 167772160L)
+		res = DNSUtils.addr2bin('10.0.0.1', cidr=32L)
+		self.assertEqual(res, 167772161L)
+		res = DNSUtils.addr2bin('10.0.0.1', cidr=31L)
+		self.assertEqual(res, 167772160L)
+
+	def testBin2addr(self):
+		res = DNSUtils.bin2addr(167772160L)
+		self.assertEqual(res, '10.0.0.0')
+
 class JailTests(unittest.TestCase):
 
 	def testSetBackend_gh83(self):