diff --git a/vendor/github.com/hashicorp/memberlist/memberlist.go b/vendor/github.com/hashicorp/memberlist/memberlist.go
index e1e38fc941..bdf333b436 100644
--- a/vendor/github.com/hashicorp/memberlist/memberlist.go
+++ b/vendor/github.com/hashicorp/memberlist/memberlist.go
@@ -308,23 +308,17 @@ func (m *Memberlist) tcpLookupIP(host string, defaultPort uint16) ([]ipPort, err
 // resolveAddr is used to resolve the address into an address,
 // port, and error. If no port is given, use the default
 func (m *Memberlist) resolveAddr(hostStr string) ([]ipPort, error) {
-	// Normalize the incoming string to host:port so we can apply Go's
-	// parser to it.
-	port := uint16(0)
-	if !hasPort(hostStr) {
-		hostStr += ":" + strconv.Itoa(m.config.BindPort)
-	}
+	// This captures the supplied port, or the default one.
+	hostStr = ensurePort(hostStr, m.config.BindPort)
 	host, sport, err := net.SplitHostPort(hostStr)
 	if err != nil {
 		return nil, err
 	}
-
-	// This will capture the supplied port, or the default one added above.
 	lport, err := strconv.ParseUint(sport, 10, 16)
 	if err != nil {
 		return nil, err
 	}
-	port = uint16(lport)
+	port := uint16(lport)
 
 	// If it looks like an IP address we are done. The SplitHostPort() above
 	// will make sure the host part is in good shape for parsing, even for
diff --git a/vendor/github.com/hashicorp/memberlist/suspicion.go b/vendor/github.com/hashicorp/memberlist/suspicion.go
index 5f573e1fc6..f8aa9e20a8 100644
--- a/vendor/github.com/hashicorp/memberlist/suspicion.go
+++ b/vendor/github.com/hashicorp/memberlist/suspicion.go
@@ -117,7 +117,7 @@ func (s *suspicion) Confirm(from string) bool {
 	// stop the timer then we will call the timeout function directly from
 	// here.
 	n := atomic.AddInt32(&s.n, 1)
-	elapsed := time.Now().Sub(s.start)
+	elapsed := time.Since(s.start)
 	remaining := remainingSuspicionTime(n, s.k, elapsed, s.min, s.max)
 	if s.timer.Stop() {
 		if remaining > 0 {
diff --git a/vendor/github.com/hashicorp/memberlist/util.go b/vendor/github.com/hashicorp/memberlist/util.go
index a4f926e3ab..e2381a6986 100644
--- a/vendor/github.com/hashicorp/memberlist/util.go
+++ b/vendor/github.com/hashicorp/memberlist/util.go
@@ -217,20 +217,6 @@ func decodeCompoundMessage(buf []byte) (trunc int, parts [][]byte, err error) {
 	return
 }
 
-// Given a string of the form "host", "host:port",
-// "ipv6::addr" or "[ipv6::address]:port",
-// return true if the string includes a port.
-func hasPort(s string) bool {
-	last := strings.LastIndex(s, ":")
-	if last == -1 {
-		return false
-	}
-	if s[0] == '[' {
-		return s[last-1] == ']'
-	}
-	return strings.Index(s, ":") == last
-}
-
 // compressPayload takes an opaque input buffer, compresses it
 // and wraps it in a compress{} message that is encoded.
 func compressPayload(inp []byte) (*bytes.Buffer, error) {
@@ -294,3 +280,31 @@ func decompressBuffer(c *compress) ([]byte, error) {
 func joinHostPort(host string, port uint16) string {
 	return net.JoinHostPort(host, strconv.Itoa(int(port)))
 }
+
+// hasPort is given a string of the form "host", "host:port", "ipv6::address",
+// or "[ipv6::address]:port", and returns true if the string includes a port.
+func hasPort(s string) bool {
+	// IPv6 address in brackets.
+	if strings.LastIndex(s, "[") == 0 {
+		return strings.LastIndex(s, ":") > strings.LastIndex(s, "]")
+	}
+
+	// Otherwise the presence of a single colon determines if there's a port
+	// since IPv6 addresses outside of brackets (count > 1) can't have a
+	// port.
+	return strings.Count(s, ":") == 1
+}
+
+// ensurePort makes sure the given string has a port number on it, otherwise it
+// appends the given port as a default.
+func ensurePort(s string, port int) string {
+	if hasPort(s) {
+		return s
+	}
+
+	// If this is an IPv6 address, the join call will add another set of
+	// brackets, so we have to trim before we add the default port.
+	s = strings.Trim(s, "[]")
+	s = net.JoinHostPort(s, strconv.Itoa(port))
+	return s
+}
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 4d9f8e68fe..5fa77838ed 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -59,7 +59,7 @@
 		{"path":"github.com/hashicorp/hil","checksumSHA1":"kqCMCHy2b+RBMKC+ER+OPqp8C3E=","revision":"1e86c6b523c55d1fa6c6e930ce80b548664c95c2","revisionTime":"2016-07-11T23:18:37Z"},
 		{"path":"github.com/hashicorp/hil/ast","checksumSHA1":"UICubs001+Q4MsUf9zl2vcMzWQQ=","revision":"1e86c6b523c55d1fa6c6e930ce80b548664c95c2","revisionTime":"2016-07-11T23:18:37Z"},
 		{"path":"github.com/hashicorp/logutils","checksumSHA1":"vt+P9D2yWDO3gdvdgCzwqunlhxU=","revision":"0dc08b1671f34c4250ce212759ebd880f743d883","revisionTime":"2015-06-09T07:04:31Z"},
-		{"path":"github.com/hashicorp/memberlist","checksumSHA1":"vwj2yOi577Mmn+IfJwV8YXYeALk=","revision":"687988a0b5daaf7ed5051e5e374aef27f8254822","revisionTime":"2017-09-19T17:31:51Z"},
+		{"path":"github.com/hashicorp/memberlist","checksumSHA1":"W1MrXPyP9I630SENN7b9Vn/K5r0=","revision":"caa5d20d6a642b7543b3745e54031a96008bee57","revisionTime":"2017-11-10T01:18:39Z"},
 		{"path":"github.com/hashicorp/net-rpc-msgpackrpc","checksumSHA1":"qnlqWJYV81ENr61SZk9c65R1mDo=","revision":"a14192a58a694c123d8fe5481d4a4727d6ae82f3","revisionTime":"2015-11-16T02:03:38Z"},
 		{"path":"github.com/hashicorp/raft","checksumSHA1":"JjJtGJi1ywWhVhs/PvTXxe4TeD8=","revision":"6d14f0c70869faabd9e60ba7ed88a6cbbd6a661f","revisionTime":"2017-10-03T22:09:13Z","version":"v1.0.0","versionExact":"v1.0.0"},
 		{"path":"github.com/hashicorp/raft-boltdb","checksumSHA1":"QAxukkv54/iIvLfsUP6IK4R0m/A=","revision":"d1e82c1ec3f15ee991f7cc7ffd5b67ff6f5bbaee","revisionTime":"2015-02-01T20:08:39Z"},