diff --git a/test/Makefile.am b/test/Makefile.am
index f8f546c6..5432dcb5 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -51,6 +51,8 @@ rtorrent_Test_Rpc_SOURCES = $(rtorrent_Test_Common) \
 rtorrent_Test_Src_SOURCES = $(rtorrent_Test_Common) \
 	src/test_command_dynamic.cc \
 	src/test_command_dynamic.h \
+	src/test_command_ip.cc \
+	src/test_command_ip.h \
 	src/test_command_system.cc \
 	src/test_command_system.h \
 	src/test_command_path.cc \
diff --git a/test/src/test_command_ip.cc b/test/src/test_command_ip.cc
new file mode 100644
index 00000000..9b34f05f
--- /dev/null
+++ b/test/src/test_command_ip.cc
@@ -0,0 +1,55 @@
+#include "config.h"
+
+#include "test/src/test_command_ip.h"
+
+#include <cstdint>
+
+CPPUNIT_TEST_SUITE_REGISTRATION(TestCommandIp);
+
+bool ipv4_range_parse(const char* address, uint32_t* address_start, uint32_t* address_end);
+
+static uint32_t
+ipv4(uint32_t a, uint32_t b, uint32_t c, uint32_t d) {
+  return (a << 24) | (b << 16) | (c << 8) | d;
+}
+
+#define RANGE_ASSERT(address, expected_start, expected_end)             \
+  {                                                                     \
+    uint32_t start = 0;                                                 \
+    uint32_t end = 0;                                                   \
+                                                                        \
+    CPPUNIT_ASSERT(ipv4_range_parse(address, &start, &end));            \
+    CPPUNIT_ASSERT_EQUAL(expected_start, start);                        \
+    CPPUNIT_ASSERT_EQUAL(expected_end, end);                            \
+  }
+
+void
+TestCommandIp::test_single_address() {
+  RANGE_ASSERT("10.1.2.3", ipv4(10, 1, 2, 3), ipv4(10, 1, 2, 3));
+}
+
+void
+TestCommandIp::test_explicit_range() {
+  RANGE_ASSERT("10.1.2.3-10.1.2.9", ipv4(10, 1, 2, 3), ipv4(10, 1, 2, 9));
+}
+
+void
+TestCommandIp::test_cidr() {
+  RANGE_ASSERT("10.0.0.0/8", ipv4(10, 0, 0, 0), ipv4(10, 255, 255, 255));
+  RANGE_ASSERT("10.1.2.0/24", ipv4(10, 1, 2, 0), ipv4(10, 1, 2, 255));
+  RANGE_ASSERT("10.1.2.128/25", ipv4(10, 1, 2, 128), ipv4(10, 1, 2, 255));
+  RANGE_ASSERT("10.1.2.3/31", ipv4(10, 1, 2, 2), ipv4(10, 1, 2, 3));
+}
+
+void
+TestCommandIp::test_cidr_zero_mask() {
+  RANGE_ASSERT("0.0.0.0/0", ipv4(0, 0, 0, 0), ipv4(255, 255, 255, 255));
+  RANGE_ASSERT("10.1.2.3/0", ipv4(0, 0, 0, 0), ipv4(255, 255, 255, 255));
+}
+
+void
+TestCommandIp::test_cidr_full_mask() {
+  RANGE_ASSERT("10.1.2.3/32", ipv4(10, 1, 2, 3), ipv4(10, 1, 2, 3));
+  RANGE_ASSERT("0.0.0.0/32", ipv4(0, 0, 0, 0), ipv4(0, 0, 0, 0));
+  RANGE_ASSERT("255.255.255.255/32", ipv4(255, 255, 255, 255), ipv4(255, 255, 255, 255));
+}
diff --git a/test/src/test_command_ip.h b/test/src/test_command_ip.h
new file mode 100644
index 00000000..9d45a71b
--- /dev/null
+++ b/test/src/test_command_ip.h
@@ -0,0 +1,25 @@
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+
+// ipv4_range_parse is a pure function, so this does not use test_fixture and
+// the mock and logging setup that comes with it.
+class TestCommandIp : public CppUnit::TestFixture {
+  CPPUNIT_TEST_SUITE(TestCommandIp);
+
+  CPPUNIT_TEST(test_single_address);
+  CPPUNIT_TEST(test_explicit_range);
+
+  CPPUNIT_TEST(test_cidr);
+  CPPUNIT_TEST(test_cidr_zero_mask);
+  CPPUNIT_TEST(test_cidr_full_mask);
+
+  CPPUNIT_TEST_SUITE_END();
+
+public:
+  void test_single_address();
+  void test_explicit_range();
+
+  void test_cidr();
+  void test_cidr_zero_mask();
+  void test_cidr_full_mask();
+};