diff --git a/test/net/TestIPv4Address.cxx b/test/net/TestIPv4Address.cxx
index a6c05e681..94c8c8592 100644
--- a/test/net/TestIPv4Address.cxx
+++ b/test/net/TestIPv4Address.cxx
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2012-2022 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,6 +29,7 @@
 
 #include "net/IPv4Address.hxx"
 #include "net/ToString.hxx"
+#include "util/Compiler.h"
 
 #include <gtest/gtest.h>
 
@@ -38,6 +39,70 @@
 #include <arpa/inet.h>
 #endif
 
+#if GCC_CHECK_VERSION(11,0)
+/* suppress warning for calling GetSize() on uninitialized object */
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+
+TEST(IPv4AddressTest, Basic)
+{
+	IPv4Address dummy;
+	EXPECT_EQ(dummy.GetSize(), sizeof(struct sockaddr_in));
+}
+
+TEST(IPv4AddressTest, Port)
+{
+	IPv4Address a(12345);
+	EXPECT_EQ(a.GetPort(), 12345u);
+
+	a.SetPort(42);
+	EXPECT_EQ(a.GetPort(), 42u);
+}
+
+TEST(IPv4AddressTest, NumericAddress)
+{
+	IPv4Address a(12345);
+	EXPECT_EQ(a.GetNumericAddress(), 0u);
+	EXPECT_EQ(a.GetNumericAddressBE(), 0u);
+
+	a = IPv4Address(192, 168, 1, 2, 42);
+	EXPECT_EQ(a.GetNumericAddress(), 0xc0a80102);
+	EXPECT_EQ(a.GetNumericAddressBE(), ToBE32(0xc0a80102));
+}
+
+TEST(IPv4AddressTest, Mask)
+{
+	EXPECT_EQ(IPv4Address::MaskFromPrefix(0).GetNumericAddress(),
+		  IPv4Address(0, 0, 0, 0, 0).GetNumericAddress());
+	EXPECT_EQ(IPv4Address::MaskFromPrefix(1).GetNumericAddress(),
+		  IPv4Address(128, 0, 0, 0, 0).GetNumericAddress());
+	EXPECT_EQ(IPv4Address::MaskFromPrefix(23).GetNumericAddress(),
+		  IPv4Address(255, 255, 254, 0, 0).GetNumericAddress());
+	EXPECT_EQ(IPv4Address::MaskFromPrefix(24).GetNumericAddress(),
+		  IPv4Address(255, 255, 255, 0, 0).GetNumericAddress());
+	EXPECT_EQ(IPv4Address::MaskFromPrefix(32).GetNumericAddress(),
+		  IPv4Address(255, 255, 255, 255, 0).GetNumericAddress());
+}
+
+TEST(IPv4AddressTest, And)
+{
+	EXPECT_EQ((IPv4Address::MaskFromPrefix(32) &
+		   IPv4Address(192, 168, 1, 2, 0)).GetNumericAddress(),
+		  IPv4Address(192, 168, 1, 2, 0).GetNumericAddress());
+	EXPECT_EQ((IPv4Address::MaskFromPrefix(24) &
+		   IPv4Address(192, 168, 1, 2, 0)).GetNumericAddress(),
+		  IPv4Address(192, 168, 1, 0, 0).GetNumericAddress());
+	EXPECT_EQ((IPv4Address::MaskFromPrefix(16) &
+		   IPv4Address(192, 168, 1, 2, 0)).GetNumericAddress(),
+		  IPv4Address(192, 168, 0, 0, 0).GetNumericAddress());
+	EXPECT_EQ((IPv4Address::MaskFromPrefix(8) &
+		   IPv4Address(192, 168, 1, 2, 0)).GetNumericAddress(),
+		  IPv4Address(192, 0, 0, 0, 0).GetNumericAddress());
+	EXPECT_EQ((IPv4Address::MaskFromPrefix(0) &
+		   IPv4Address(192, 168, 1, 2, 0)).GetNumericAddress(),
+		  IPv4Address(0, 0, 0, 0, 0).GetNumericAddress());
+}
+
 static std::string
 ToString(const struct in_addr &a)
 {
diff --git a/test/net/TestIPv6Address.cxx b/test/net/TestIPv6Address.cxx
index cdadf6a7f..3e0dac6b9 100644
--- a/test/net/TestIPv6Address.cxx
+++ b/test/net/TestIPv6Address.cxx
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 Max Kellermann <max.kellermann@gmail.com>
+ * Copyright 2012-2022 Max Kellermann <max.kellermann@gmail.com>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,6 +29,7 @@
 
 #include "net/IPv6Address.hxx"
 #include "net/ToString.hxx"
+#include "util/Compiler.h"
 
 #include <gtest/gtest.h>
 
@@ -38,6 +39,67 @@
 #include <arpa/inet.h>
 #endif
 
+#if GCC_CHECK_VERSION(11,0)
+/* suppress warning for calling GetSize() on uninitialized object */
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+
+TEST(IPv6AddressTest, Basic)
+{
+	IPv6Address dummy;
+	EXPECT_EQ(dummy.GetSize(), sizeof(struct sockaddr_in6));
+}
+
+TEST(IPv6AddressTest, Port)
+{
+	IPv6Address a(12345);
+	EXPECT_EQ(a.GetPort(), 12345u);
+
+	a.SetPort(42);
+	EXPECT_EQ(a.GetPort(), 42u);
+}
+
+static bool
+operator==(const struct in6_addr &a, const struct in6_addr &b)
+{
+	return memcmp(&a, &b, sizeof(a)) == 0;
+}
+
+TEST(IPv6AddressTest, Mask)
+{
+	EXPECT_EQ(IPv6Address::MaskFromPrefix(0).GetAddress(),
+		  IPv6Address(0, 0, 0, 0, 0, 0, 0, 0, 0).GetAddress());
+	EXPECT_EQ(IPv6Address::MaskFromPrefix(128).GetAddress(),
+		  IPv6Address(0xffff, 0xffff, 0xffff, 0xffff,
+			      0xffff, 0xffff, 0xffff, 0xffff, 0).GetAddress());
+	EXPECT_EQ(IPv6Address::MaskFromPrefix(127).GetAddress(),
+		  IPv6Address(0xffff, 0xffff, 0xffff, 0xffff,
+			      0xffff, 0xffff, 0xffff, 0xfffe, 0).GetAddress());
+	EXPECT_EQ(IPv6Address::MaskFromPrefix(64).GetAddress(),
+		  IPv6Address(0xffff, 0xffff, 0xffff, 0xffff,
+			      0, 0, 0, 0, 0).GetAddress());
+	EXPECT_EQ(IPv6Address::MaskFromPrefix(56).GetAddress(),
+		  IPv6Address(0xffff, 0xffff, 0xffff, 0xff00,
+			      0, 0, 0, 0, 0).GetAddress());
+}
+
+TEST(IPv6AddressTest, And)
+{
+	EXPECT_EQ((IPv6Address::MaskFromPrefix(128) &
+		   IPv6Address::MaskFromPrefix(56)).GetAddress(),
+		  IPv6Address::MaskFromPrefix(56).GetAddress());
+	EXPECT_EQ((IPv6Address::MaskFromPrefix(48) &
+		   IPv6Address(0x2a00, 0x1450, 0x4001, 0x816,
+			       0, 0, 0, 0x200e, 0)).GetAddress(),
+		  IPv6Address(0x2a00, 0x1450, 0x4001, 0,
+			      0, 0, 0, 0, 0).GetAddress());
+	EXPECT_EQ((IPv6Address::MaskFromPrefix(24) &
+		   IPv6Address(0x2a00, 0x1450, 0x4001, 0x816,
+			       0, 0, 0, 0x200e, 0)).GetAddress(),
+		  IPv6Address(0x2a00, 0x1400, 0, 0,
+			      0, 0, 0, 0, 0).GetAddress());
+}
+
 static std::string
 ToString(const struct in6_addr &a)
 {