diff --git a/pkg/proxy/util/endpoints.go b/pkg/proxy/util/endpoints.go
new file mode 100644
index 00000000000..32e770d4f94
--- /dev/null
+++ b/pkg/proxy/util/endpoints.go
@@ -0,0 +1,51 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/golang/glog"
+)
+
+// IPPart returns just the IP part of an IP or IP:port or endpoint string. If the IP
+// part is an IPv6 address enclosed in brackets (e.g. "[fd00:1::5]:9999"),
+// then the brackets are stripped as well.
+func IPPart(s string) string {
+	if ip := net.ParseIP(s); ip != nil {
+		// IP address without port
+		return s
+	}
+	// Must be IP:port
+	ip, _, err := net.SplitHostPort(s)
+	if err != nil {
+		glog.Errorf("Error parsing '%s': %v", s, err)
+		return ""
+	}
+	return ip
+}
+
+// ToCIDR returns a host address of the form <ip-address>/32 for
+// IPv4 and <ip-address>/128 for IPv6
+func ToCIDR(ip net.IP) string {
+	len := 32
+	if ip.To4() == nil {
+		len = 128
+	}
+	return fmt.Sprintf("%s/%d", ip.String(), len)
+}
diff --git a/pkg/proxy/util/endpoints_test.go b/pkg/proxy/util/endpoints_test.go
new file mode 100644
index 00000000000..618f59e96a8
--- /dev/null
+++ b/pkg/proxy/util/endpoints_test.go
@@ -0,0 +1,68 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"net"
+	"testing"
+)
+
+func TestIPPart(t *testing.T) {
+	const noError = ""
+
+	testCases := []struct {
+		endpoint      string
+		expectedIP    string
+		expectedError string
+	}{
+		{"1.2.3.4", "1.2.3.4", noError},
+		{"1.2.3.4:9999", "1.2.3.4", noError},
+		{"2001:db8::1:1", "2001:db8::1:1", noError},
+		{"[2001:db8::2:2]:9999", "2001:db8::2:2", noError},
+		{"1.2.3.4::9999", "", "too many colons"},
+		{"1.2.3.4:[0]", "", "unexpected '[' in address"},
+	}
+
+	for _, tc := range testCases {
+		ip := IPPart(tc.endpoint)
+		if tc.expectedError == noError {
+			if ip != tc.expectedIP {
+				t.Errorf("Unexpected IP for %s: Expected: %s, Got %s", tc.endpoint, tc.expectedIP, ip)
+			}
+		} else if ip != "" {
+			t.Errorf("Error did not occur for %s, expected: '%s' error", tc.endpoint, tc.expectedError)
+		}
+	}
+}
+
+func TestToCIDR(t *testing.T) {
+	testCases := []struct {
+		ip           string
+		expectedAddr string
+	}{
+		{"1.2.3.4", "1.2.3.4/32"},
+		{"2001:db8::1:1", "2001:db8::1:1/128"},
+	}
+
+	for _, tc := range testCases {
+		ip := net.ParseIP(tc.ip)
+		addr := ToCIDR(ip)
+		if addr != tc.expectedAddr {
+			t.Errorf("Unexpected host address for %s: Expected: %s, Got %s", tc.ip, tc.expectedAddr, addr)
+		}
+	}
+}