diff --git a/networking/udhcp/Config.src b/networking/udhcp/Config.src
index 79f58e9d3..e393429a9 100644
--- a/networking/udhcp/Config.src
+++ b/networking/udhcp/Config.src
@@ -132,14 +132,22 @@ config UDHCPC_DEFAULT_DECLINE_SCRIPT
 	string "Absolute path to decline script"
 	default "/usr/share/udhcpc/decline.script"
 	depends on UDHCPC
 	help
 	The script is called after client receives offer from server.
 	Decline script returns 0 when offer should be accepted.
 
+config FEATURE_UDHCPC_COS
+	bool "Support Class of Service for DHCP Client"
+	default y
+	depends on UDHCPC
+	help
+	If selected, udhcpc will set -y socket priority.
+	script returns 1.
+
 config UDHCP_DEBUG
 	int "Maximum verbosity level (0..9)"
 	default 2
 	range 0 9
 	depends on UDHCPD || UDHCPC || UDHCPC6 || DHCPRELAY
 	help
 	Verbosity can be increased with multiple -v options.
diff --git a/networking/udhcp/d6_dhcpc.c b/networking/udhcp/d6_dhcpc.c
index 8d11a7539..43760a112 100644
--- a/networking/udhcp/d6_dhcpc.c
+++ b/networking/udhcp/d6_dhcpc.c
@@ -125,14 +125,15 @@ static const char udhcpc6_longopts[] ALIGN1 =
 	"foreground\0"     No_argument       "f"
 	"stateless\0"      No_argument       "l"
 	USE_FOR_MMU(
 	"background\0"     No_argument       "b"
 	)
 ///	IF_FEATURE_UDHCPC_ARPING("arping\0"	No_argument       "a")
 	IF_FEATURE_UDHCP_PORT("client-port\0"	Required_argument "P")
+	IF_FEATURE_UDHCPC_COS("cos\0"	Required_argument "y")
 	;
 #endif
 /* Must match getopt32 option string order */
 enum {
 	OPT_i = 1 << 0,
 	OPT_n = 1 << 1,
 	OPT_p = 1 << 2,
@@ -1147,14 +1148,17 @@ static void client_background(void)
 //usage:     "\n	-S		Log to syslog too"
 //usage:	IF_FEATURE_UDHCP_PORT(
 //usage:     "\n	-P PORT		Use PORT (default 546)"
 //usage:	)
 ////usage:	IF_FEATURE_UDHCPC_ARPING(
 ////usage:     "\n	-a		Use arping to validate offered address"
 ////usage:	)
+//usage:	IF_FEATURE_UDHCPC_COS(
+//usage:     "\n	-y PRIORITY	CoS value 0 .. 7, default 0"
+//usage:	)
 //usage:     "\n	-l		Send 'information request' instead of 'solicit'"
 //usage:     "\n			(used for servers which do not assign IPv6 addresses)"
 //usage:     "\n	-r IPv6		Request this address ('no' to not request any IP)"
 //usage:     "\n	-d		Request prefix"
 //usage:     "\n	-o		Don't request any options (unless -O is given)"
 //usage:     "\n	-O OPT		Request option OPT from server (cumulative)"
 //usage:     "\n	-x OPT:VAL	Include option OPT in sent packets (cumulative)"
@@ -1208,23 +1212,25 @@ int udhcpc6_main(int argc UNUSED_PARAM, char **argv)
 	/* Parse command line */
 	opt = getopt32long(argv, "^"
 		/* O,x: list; -T,-t,-A take numeric param */
 		"i:np:qRr:s:T:+t:+SA:+O:*ox:*fld"
 		USE_FOR_MMU("b")
 		///IF_FEATURE_UDHCPC_ARPING("a")
 		IF_FEATURE_UDHCP_PORT("P:")
+		IF_FEATURE_UDHCPC_COS("y:+")
 		"v"
 		"\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */
 		, udhcpc6_longopts
 		, &client_data.interface, &client_data.pidfile, &str_r /* i,p */
 		, &client_data.script /* s */
 		, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
 		, &list_O
 		, &list_x
 		IF_FEATURE_UDHCP_PORT(, &str_P)
+		IF_FEATURE_UDHCPC_COS(, &sk_prio)
 		IF_UDHCP_VERBOSE(, &dhcp_verbose)
 	);
 	requested_ipv6 = NULL;
 	option_mask32 |= OPT_r;
 	if (opt & OPT_l) {
 		/* for -l, do not require IPv6 assignment from server */
 		option_mask32 &= ~OPT_r;
diff --git a/networking/udhcp/d6_packet.c b/networking/udhcp/d6_packet.c
index c1949f6e3..141cc5e59 100644
--- a/networking/udhcp/d6_packet.c
+++ b/networking/udhcp/d6_packet.c
@@ -107,14 +107,22 @@ int FAST_FUNC d6_send_raw_packet_from_client_data_ifindex(
 			(uint8_t *)&packet + 4,
 			offsetof(struct ip6_udp_d6_packet, data) - 4 + d6_pkt_size
 	);
 	/* fix 'hop limit' and 'next header' after UDP checksumming */
 	packet.ip6.ip6_hlim = 1; /* observed Windows machines to use hlim=1 */
 	packet.ip6.ip6_nxt = IPPROTO_UDP;
 
+IF_FEATURE_UDHCPC_COS(
+	if (sk_prio) {
+		if (setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &sk_prio, sizeof(sk_prio))) {
+			log1s("raw: SO_PRIORITY (dscp v6) setsockopt() failed");
+		}
+	})
+
+
 	d6_dump_packet(d6_pkt);
 	result = sendto(fd, &packet, offsetof(struct ip6_udp_d6_packet, data) + d6_pkt_size,
 			/*flags:*/ 0,
 			(struct sockaddr *) &dest_sll, sizeof(dest_sll)
 	);
 	msg = "sendto";
  ret_close:
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 2b75940fe..f8c0baceb 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -76,14 +76,15 @@ static const char udhcpc_longopts[] ALIGN1 =
 	USE_FOR_MMU(
 	"background\0"     No_argument       "b"
 	)
 	"broadcast\0"      No_argument       "B"
 	IF_FEATURE_UDHCPC_ARPING("arping\0"	Optional_argument "a")
 	IF_FEATURE_UDHCP_PORT("client-port\0"	Required_argument "P")
 	IF_FEATURE_UDHCPC_DECLINE("decline-script\0"	Required_argument "d")
+	IF_FEATURE_UDHCPC_COS("cos\0"	Required_argument "y")
 	;
 #endif
 /* Must match getopt32 option string order */
 enum {
 	OPT_C = 1 << 0,
 	OPT_V = 1 << 1,
 	OPT_F = 1 << 2,
@@ -1237,14 +1238,17 @@ static int udhcp_run_decline_script(struct dhcp_packet *packet)
 //usage:     "\n	-q		Exit after obtaining lease"
 //usage:     "\n	-R		Release IP on exit"
 //usage:     "\n	-f		Run in foreground"
 //usage:     "\n	-S		Log to syslog too"
 //usage:	IF_FEATURE_UDHCPC_ARPING(
 //usage:     "\n	-a[MSEC]	Validate offered address with ARP ping"
 //usage:	)
+//usage:	IF_FEATURE_UDHCPC_COS(
+//usage:     "\n	-y PRIORITY	CoS value 0 .. 7, default 0"
+//usage:	)
 //usage:     "\n	-r IP		Request this IP address"
 //usage:     "\n	-o		Don't request any options (unless -O is given)"
 //usage:     "\n	-O OPT		Request option OPT from server (cumulative)"
 //usage:     "\n	-x OPT:VAL	Include option OPT in sent packets (cumulative)"
 //usage:     "\n			Examples of string, numeric, and hex byte opts:"
 //usage:     "\n			-x hostname:bbox - option 12"
 //usage:     "\n			-x lease:3600 - option 51 (lease time)"
@@ -1303,27 +1307,29 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 	opt = getopt32long(argv, "^"
 		/* O,x: list; -T,-t,-A take numeric param */
 		"CV:F:i:np:qRr:s:T:+t:+SA:+O:*ox:*fB"
 		USE_FOR_MMU("b")
 		IF_FEATURE_UDHCPC_ARPING("a::")
 		IF_FEATURE_UDHCP_PORT("P:")
 		IF_FEATURE_UDHCPC_DECLINE("d:")
+		IF_FEATURE_UDHCPC_COS("y:+")
 		"v"
 		"\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */
 		, udhcpc_longopts
 		, &str_V, &str_F
 		, &client_data.interface, &client_data.pidfile /* i,p */
 		, &str_r /* r */
 		, &client_data.script /* s */
 		, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
 		, &list_O
 		, &list_x
 		IF_FEATURE_UDHCPC_ARPING(, &str_a)
 		IF_FEATURE_UDHCP_PORT(, &str_P)
 		IF_FEATURE_UDHCPC_DECLINE(, &client_data.decline_script)
+		IF_FEATURE_UDHCPC_COS(, &sk_prio)
 		IF_UDHCP_VERBOSE(, &dhcp_verbose)
 	);
 	if (opt & OPT_F) {
 		char *p;
 		unsigned len;
 		/* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
 		len = strlen(str_F);
diff --git a/networking/udhcp/dhcpc.h b/networking/udhcp/dhcpc.h
index ed51683dc..4b5659aef 100644
--- a/networking/udhcp/dhcpc.h
+++ b/networking/udhcp/dhcpc.h
@@ -3,14 +3,16 @@
  * Licensed under GPLv2, see file LICENSE in this source tree.
  */
 #ifndef UDHCP_DHCPC_H
 #define UDHCP_DHCPC_H 1
 
 PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 
+IF_FEATURE_UDHCPC_COS(extern uint32_t sk_prio;)
+
 struct client_data_t {
 	uint8_t client_mac[6];          /* Our mac address */
 	IF_FEATURE_UDHCP_PORT(uint16_t port;)
 	int ifindex;                    /* Index number of the interface to use */
 	uint32_t xid;
 	uint8_t opt_mask[256 / 8];      /* Bitmask of options to send (-O option) */
 // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ TODO: DHCPv6 has 16-bit option numbers
diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c
index 78f580ce9..ef56e54d2 100644
--- a/networking/udhcp/packet.c
+++ b/networking/udhcp/packet.c
@@ -8,14 +8,16 @@
  */
 #include "common.h"
 #include "dhcpd.h"
 #include <netinet/in.h>
 #include <netinet/if_ether.h>
 #include <netpacket/packet.h>
 
+IF_FEATURE_UDHCPC_COS(uint32_t sk_prio;)
+
 #if ENABLE_UDHCPC || ENABLE_UDHCPD
 void FAST_FUNC udhcp_init_header(struct dhcp_packet *packet, char type)
 {
 	memset(packet, 0, sizeof(*packet));
 	packet->op = BOOTREQUEST; /* if client to a server */
 	switch (type) {
 	case DHCPOFFER:
@@ -170,14 +172,21 @@ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt,
 	/* but for sending, it is set to IP packet len */
 	packet.ip.tot_len = htons(IP_UDP_DHCP_SIZE - padding);
 	packet.ip.ihl = sizeof(packet.ip) >> 2;
 	packet.ip.version = IPVERSION;
 	packet.ip.ttl = IPDEFTTL;
 	packet.ip.check = inet_cksum(&packet.ip, sizeof(packet.ip));
 
+IF_FEATURE_UDHCPC_COS(
+	if (sk_prio) {
+		if (setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &sk_prio, sizeof(sk_prio))) {
+			log1s("raw: SO_PRIORITY (dscp v6) setsockopt() failed");
+		}
+	})
+
 	udhcp_dump_packet(dhcp_pkt);
 	result = sendto(fd, &packet, IP_UDP_DHCP_SIZE - padding, /*flags:*/ 0,
 			(struct sockaddr *) &dest_sll, sizeof(dest_sll));
 	msg = "sendto";
  ret_close:
 	close(fd);
 	if (result < 0) {