diff --git a/interviews/match-ip-addresses/README.md b/interviews/match-ip-addresses/README.md
new file mode 100644
index 0000000..f172ddb
--- /dev/null
+++ b/interviews/match-ip-addresses/README.md
@@ -0,0 +1,9 @@
+# IP Blacklist
+
+Handle a IP blacklist structure in which you receive IP Addresses in the form of:
+
+1. Single IP: `10.0.0.1`
+2. IP Range: `11.0.0.1-11.0.0.255`
+3. IP CIDR: `12.0.0.0/16`
+
+And then you can check if a given IP matches any of those rules.
diff --git a/interviews/match-ip-addresses/main.go b/interviews/match-ip-addresses/main.go
new file mode 100644
index 0000000..dd8a4e2
--- /dev/null
+++ b/interviews/match-ip-addresses/main.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"encoding/binary"
+	"fmt"
+	"net"
+	"strings"
+)
+
+func netIPToUint32(ip []byte) uint32 {
+	if len(ip) == 16 {
+		return binary.BigEndian.Uint32(ip[12:16])
+	}
+	return binary.BigEndian.Uint32(ip)
+}
+
+type IPRange struct {
+	Start uint32
+	End   uint32
+}
+
+type IPMatcher struct {
+	ranges []IPRange
+}
+
+func int2ip(nn uint32) net.IP {
+	ip := make(net.IP, 4)
+	binary.BigEndian.PutUint32(ip, nn)
+	return ip
+}
+
+func (ipm *IPMatcher) Set(rules []string) error {
+	var ranges []IPRange
+
+	for _, rule := range rules {
+		if strings.Contains(rule, "/") {
+			// CIDR
+			_, network, err := net.ParseCIDR(rule)
+			if err != nil {
+				return fmt.Errorf("error parsing rules for %s: %s", rule, err)
+			}
+			ranges = append(ranges, IPRange{
+				Start: netIPToUint32(network.IP),
+				End:   (netIPToUint32(network.IP) & netIPToUint32(network.Mask)) | (netIPToUint32(network.Mask) ^ 0xffffffff),
+			})
+		} else if strings.Contains(rule, "-") {
+			// Range
+			parts := strings.Split(rule, "-")
+			ranges = append(ranges, IPRange{
+				Start: netIPToUint32(net.ParseIP(parts[0])),
+				End:   netIPToUint32(net.ParseIP(parts[1])),
+			})
+		} else {
+			// Single IP
+			ranges = append(ranges,
+				IPRange{
+					Start: netIPToUint32(net.ParseIP(rule)),
+					End:   netIPToUint32(net.ParseIP(rule)),
+				})
+		}
+	}
+
+	// TODO: Sort ranges
+	// TODO: Find overlapping ranges
+	ipm.ranges = ranges
+
+	return nil
+}
+
+func (ipm *IPMatcher) Matches(ip net.IP) bool {
+	incomingIp := netIPToUint32(ip)
+	for _, ipRange := range ipm.ranges {
+		if (ipRange.Start <= incomingIp) && (incomingIp <= ipRange.End) {
+			return true
+		}
+	}
+	return false
+}
+
+func main() {
+	matcher := IPMatcher{}
+	matcher.Set([]string{
+		"11.0.0.0/24",
+		"10.0.0.1",
+		"12.0.0.1-12.0.255.255",
+	})
+
+	assert(matcher.Matches(net.ParseIP("10.0.0.2")), false, "10.0.0.2 should not match")
+	assert(matcher.Matches(net.ParseIP("10.0.0.1")), true, "10.0.0.1 should match")
+	assert(matcher.Matches(net.ParseIP("11.0.0.50")), true, "11.0.0.50 should match")
+	assert(matcher.Matches(net.ParseIP("11.0.0.255")), true, "11.0.0.255 should match")
+	assert(matcher.Matches(net.ParseIP("12.0.0.0")), false, "12.0.0.0 should not match")
+	assert(matcher.Matches(net.ParseIP("12.0.50.1")), true, "12.0.50.1 should match")
+	fmt.Println("done!")
+}
+
+func assert(result, expected bool, description string) {
+	if result != expected {
+		fmt.Println(description)
+	}
+}