src/net/netip/inlining_test.go |  2 --
 src/net/netip/netip.go         | 26 +++++++++++++++++++++++++-
 src/net/netip/netip_test.go    | 50 ++++++++++++++++++++++++++++++++++++++++++++++----

diff --git a/src/net/netip/inlining_test.go b/src/net/netip/inlining_test.go
index b521eeebfd8f38cbcf3b2951523f2ba4c725d79d..98584b098df1b3a3e44b1b30e9f415d8fc92b7fe 100644
--- a/src/net/netip/inlining_test.go
+++ b/src/net/netip/inlining_test.go
@@ -36,8 +36,6 @@ 		"Addr.hasZone",
 		"Addr.Is4",
 		"Addr.Is4In6",
 		"Addr.Is6",
-		"Addr.IsLoopback",
-		"Addr.IsMulticast",
 		"Addr.IsInterfaceLocalMulticast",
 		"Addr.IsValid",
 		"Addr.IsUnspecified",
diff --git a/src/net/netip/netip.go b/src/net/netip/netip.go
index 7a189e8e16f4fb893557b9c08711495271ee42e5..92cb57efef9a6c3cea0aaf19872f7679d5592736 100644
--- a/src/net/netip/netip.go
+++ b/src/net/netip/netip.go
@@ -508,6 +508,10 @@ }
 
 // IsLinkLocalUnicast reports whether ip is a link-local unicast address.
 func (ip Addr) IsLinkLocalUnicast() bool {
+	if ip.Is4In6() {
+		ip = ip.Unmap()
+	}
+
 	// Dynamic Configuration of IPv4 Link-Local Addresses
 	// https://datatracker.ietf.org/doc/html/rfc3927#section-2.1
 	if ip.Is4() {
@@ -523,6 +527,10 @@ }
 
 // IsLoopback reports whether ip is a loopback address.
 func (ip Addr) IsLoopback() bool {
+	if ip.Is4In6() {
+		ip = ip.Unmap()
+	}
+
 	// Requirements for Internet Hosts -- Communication Layers (3.2.1.3 Addressing)
 	// https://datatracker.ietf.org/doc/html/rfc1122#section-3.2.1.3
 	if ip.Is4() {
@@ -538,6 +546,10 @@ }
 
 // IsMulticast reports whether ip is a multicast address.
 func (ip Addr) IsMulticast() bool {
+	if ip.Is4In6() {
+		ip = ip.Unmap()
+	}
+
 	// Host Extensions for IP Multicasting (4. HOST GROUP ADDRESSES)
 	// https://datatracker.ietf.org/doc/html/rfc1112#section-4
 	if ip.Is4() {
@@ -556,7 +568,7 @@ // multicast address.
 func (ip Addr) IsInterfaceLocalMulticast() bool {
 	// IPv6 Addressing Architecture (2.7.1. Pre-Defined Multicast Addresses)
 	// https://datatracker.ietf.org/doc/html/rfc4291#section-2.7.1
-	if ip.Is6() {
+	if ip.Is6() && !ip.Is4In6() {
 		return ip.v6u16(0)&0xff0f == 0xff01
 	}
 	return false // zero value
@@ -564,6 +576,10 @@ }
 
 // IsLinkLocalMulticast reports whether ip is a link-local multicast address.
 func (ip Addr) IsLinkLocalMulticast() bool {
+	if ip.Is4In6() {
+		ip = ip.Unmap()
+	}
+
 	// IPv4 Multicast Guidelines (4. Local Network Control Block (224.0.0/24))
 	// https://datatracker.ietf.org/doc/html/rfc5771#section-4
 	if ip.Is4() {
@@ -592,6 +608,10 @@ 		// Invalid or zero-value.
 		return false
 	}
 
+	if ip.Is4In6() {
+		ip = ip.Unmap()
+	}
+
 	// Match package net's IsGlobalUnicast logic. Notably private IPv4 addresses
 	// and ULA IPv6 addresses are still considered "global unicast".
 	if ip.Is4() && (ip == IPv4Unspecified() || ip == AddrFrom4([4]byte{255, 255, 255, 255})) {
@@ -609,6 +629,10 @@ // (IPv4 addresses) and RFC 4193 (IPv6 addresses). That is, it reports whether
 // ip is in 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, or fc00::/7. This is the
 // same as [net.IP.IsPrivate].
 func (ip Addr) IsPrivate() bool {
+	if ip.Is4In6() {
+		ip = ip.Unmap()
+	}
+
 	// Match the stdlib's IsPrivate logic.
 	if ip.Is4() {
 		// RFC 1918 allocates 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 as
diff --git a/src/net/netip/netip_test.go b/src/net/netip/netip_test.go
index a748ac34f13ccb9ce338425a99af0c0c43404bc3..56a6c7dacb0dc4dbb5f8bc06c13935e9bbd50d7b 100644
--- a/src/net/netip/netip_test.go
+++ b/src/net/netip/netip_test.go
@@ -591,10 +591,13 @@
 		ilm6     = mustIP("ff01::1")
 		ilmZone6 = mustIP("ff01::1%eth0")
 
-		private4a = mustIP("10.0.0.1")
-		private4b = mustIP("172.16.0.1")
-		private4c = mustIP("192.168.1.1")
-		private6  = mustIP("fd00::1")
+		private4a        = mustIP("10.0.0.1")
+		private4b        = mustIP("172.16.0.1")
+		private4c        = mustIP("192.168.1.1")
+		private6         = mustIP("fd00::1")
+		private6mapped4a = mustIP("::ffff:10.0.0.1")
+		private6mapped4b = mustIP("::ffff:172.16.0.1")
+		private6mapped4c = mustIP("::ffff:192.168.1.1")
 	)
 
 	tests := []struct {
@@ -619,6 +622,11 @@ 			ip:            unicast4,
 			globalUnicast: true,
 		},
 		{
+			name:          "unicast v6 mapped v4Addr",
+			ip:            AddrFrom16(unicast4.As16()),
+			globalUnicast: true,
+		},
+		{
 			name:          "unicast v6Addr",
 			ip:            unicast6,
 			globalUnicast: true,
@@ -640,6 +648,12 @@ 			linkLocalMulticast: true,
 			multicast:          true,
 		},
 		{
+			name:               "multicast v6 mapped v4Addr",
+			ip:                 AddrFrom16(multicast4.As16()),
+			linkLocalMulticast: true,
+			multicast:          true,
+		},
+		{
 			name:               "multicast v6Addr",
 			ip:                 multicast6,
 			linkLocalMulticast: true,
@@ -657,6 +671,11 @@ 			ip:               llu4,
 			linkLocalUnicast: true,
 		},
 		{
+			name:             "link-local unicast v6 mapped v4Addr",
+			ip:               AddrFrom16(llu4.As16()),
+			linkLocalUnicast: true,
+		},
+		{
 			name:             "link-local unicast v6Addr",
 			ip:               llu6,
 			linkLocalUnicast: true,
@@ -679,6 +698,11 @@ 		},
 		{
 			name:     "loopback v6Addr",
 			ip:       IPv6Loopback(),
+			loopback: true,
+		},
+		{
+			name:     "loopback v6 mapped v4Addr",
+			ip:       AddrFrom16(IPv6Loopback().As16()),
 			loopback: true,
 		},
 		{
@@ -714,6 +738,24 @@ 		},
 		{
 			name:          "private v6Addr",
 			ip:            private6,
+			globalUnicast: true,
+			private:       true,
+		},
+		{
+			name:          "private v6 mapped v4Addr 10/8",
+			ip:            private6mapped4a,
+			globalUnicast: true,
+			private:       true,
+		},
+		{
+			name:          "private v6 mapped v4Addr 172.16/12",
+			ip:            private6mapped4b,
+			globalUnicast: true,
+			private:       true,
+		},
+		{
+			name:          "private v6 mapped v4Addr 192.168/16",
+			ip:            private6mapped4c,
 			globalUnicast: true,
 			private:       true,
 		},