diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt
index 2d66ed688125..bb5ab6de5924 100644
--- a/Documentation/filesystems/nfs/nfsroot.txt
+++ b/Documentation/filesystems/nfs/nfsroot.txt
@@ -157,6 +157,9 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:
 		  both:        use both BOOTP and RARP but not DHCP
 		               (old option kept for backwards compatibility)
 
+		if dhcp is used, the client identifier can be used by following
+		format "ip=dhcp,client-id-type,client-id-value"
+
                 Default: any
 
   <dns0-ip>	IP address of first nameserver.
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index ed4ef09c2136..0bc7412d9e14 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -146,6 +146,10 @@ u8 root_server_path[256] = { 0, };	/* Path to mount as root */
 /* vendor class identifier */
 static char vendor_class_identifier[253] __initdata;
 
+#if defined(CONFIG_IP_PNP_DHCP)
+static char dhcp_client_identifier[253] __initdata;
+#endif
+
 /* Persistent data: */
 
 static int ic_proto_used;			/* Protocol used, if any */
@@ -728,6 +732,16 @@ ic_dhcp_init_options(u8 *options)
 			memcpy(e, vendor_class_identifier, len);
 			e += len;
 		}
+		len = strlen(dhcp_client_identifier + 1);
+		/* the minimum length of identifier is 2, include 1 byte type,
+		 * and can not be larger than the length of options
+		 */
+		if (len >= 1 && len < 312 - (e - options) - 1) {
+			*e++ = 61;
+			*e++ = len + 1;
+			memcpy(e, dhcp_client_identifier, len + 1);
+			e += len + 1;
+		}
 	}
 
 	*e++ = 255;	/* End of the list */
@@ -1557,8 +1571,24 @@ static int __init ic_proto_name(char *name)
 		return 0;
 	}
 #ifdef CONFIG_IP_PNP_DHCP
-	else if (!strcmp(name, "dhcp")) {
+	else if (!strncmp(name, "dhcp", 4)) {
+		char *client_id;
+
 		ic_proto_enabled &= ~IC_RARP;
+		client_id = strstr(name, "dhcp,");
+		if (client_id) {
+			char *v;
+
+			client_id = client_id + 5;
+			v = strchr(client_id, ',');
+			if (!v)
+				return 1;
+			*v = 0;
+			if (kstrtou8(client_id, 0, dhcp_client_identifier))
+				DBG("DHCP: Invalid client identifier type\n");
+			strncpy(dhcp_client_identifier + 1, v + 1, 251);
+			*v = ',';
+		}
 		return 1;
 	}
 #endif