diff --git a/fail2ban/server/ipdns.py b/fail2ban/server/ipdns.py
index 2841eac1..959e39c4 100644
--- a/fail2ban/server/ipdns.py
+++ b/fail2ban/server/ipdns.py
@@ -64,7 +64,7 @@ class DNSUtils:
 		if ips is not None: 
 			return ips
 		# retrieve ips
-		ips = list()
+		ips = set()
 		saveerr = None
 		for fam, ipfam in ((socket.AF_INET, IPAddr.FAM_IPv4), (socket.AF_INET6, IPAddr.FAM_IPv6)):
 			try:
@@ -75,7 +75,7 @@ class DNSUtils:
 					# (some python-versions resp. host configurations causes returning of integer there):
 					ip = IPAddr(str(result[4][0]), ipfam)
 					if ip.isValid:
-						ips.append(ip)
+						ips.add(ip)
 			except Exception as e:
 				saveerr = e
 		if not ips and saveerr:
@@ -103,19 +103,19 @@ class DNSUtils:
 	def textToIp(text, useDns):
 		""" Return the IP of DNS found in a given text.
 		"""
-		ipList = list()
+		ipList = set()
 		# Search for plain IP
 		plainIP = IPAddr.searchIP(text)
 		if plainIP is not None:
 			ip = IPAddr(plainIP)
 			if ip.isValid:
-				ipList.append(ip)
+				ipList.add(ip)
 
 		# If we are allowed to resolve -- give it a try if nothing was found
 		if useDns in ("yes", "warn") and not ipList:
 			# Try to get IP from possible DNS
 			ip = DNSUtils.dnsToIp(text)
-			ipList.extend(ip)
+			ipList.update(ip)
 			if ip and useDns == "warn":
 				logSys.warning("Determined IP using DNS Lookup: %s = %s",
 					text, ipList)
diff --git a/fail2ban/tests/filtertestcase.py b/fail2ban/tests/filtertestcase.py
index 350d46b0..b22cd0f8 100644
--- a/fail2ban/tests/filtertestcase.py
+++ b/fail2ban/tests/filtertestcase.py
@@ -1800,7 +1800,7 @@ class DNSUtilsNetworkTests(unittest.TestCase):
 
 	def testUseDns(self):
 		res = DNSUtils.textToIp('www.example.com', 'no')
-		self.assertEqual(res, [])
+		self.assertSortedEqual(res, [])
 		res = DNSUtils.textToIp('www.example.com', 'warn')
 		# sort ipaddr, IPv4 is always smaller as IPv6
 		self.assertSortedEqual(res, ['93.184.216.34', '2606:2800:220:1:248:1893:25c8:1946'])
@@ -1821,12 +1821,13 @@ class DNSUtilsNetworkTests(unittest.TestCase):
 				# sort ipaddr, IPv4 is always smaller as IPv6
 				self.assertSortedEqual(res, ['93.184.216.34', '2606:2800:220:1:248:1893:25c8:1946'])
 			else:
-				self.assertEqual(res, [])
+				self.assertSortedEqual(res, [])
 		# pure ips:
 		for s in ('93.184.216.34', '2606:2800:220:1:248:1893:25c8:1946'):
 			ips = DNSUtils.textToIp(s, 'yes')
-			self.assertEqual(ips, [s])
-			self.assertTrue(isinstance(ips[0], IPAddr))
+			self.assertSortedEqual(ips, [s])
+			for ip in ips:
+				self.assertTrue(isinstance(ip, IPAddr))
 
 	def testIpToName(self):
 		unittest.F2B.SkipIfNoNetwork()
diff --git a/fail2ban/tests/utils.py b/fail2ban/tests/utils.py
index d6a5e678..31822c76 100644
--- a/fail2ban/tests/utils.py
+++ b/fail2ban/tests/utils.py
@@ -322,12 +322,16 @@ def initTests(opts):
 		# precache all wrong dns to ip's used in test cases:
 		c = DNSUtils.CACHE_nameToIp
 		for i in (
-			('999.999.999.999', []),
-			('abcdef.abcdef', []),
-			('192.168.0.', []),
-			('failed.dns.ch', []),
+			('999.999.999.999', set()),
+			('abcdef.abcdef', set()),
+			('192.168.0.', set()),
+			('failed.dns.ch', set()),
 		):
 			c.set(*i)
+		# if fast - precache all host names as localhost addresses (speed-up getSelfIPs/ignoreself):
+		if unittest.F2B.fast: # pragma: no cover
+			for i in DNSUtils.getSelfNames():
+				c.set(i, DNSUtils.dnsToIp('localhost'))
 
 
 def mtimesleep():