diff --git a/firmware/test.cpp b/firmware/test.cpp
index a564458..b95fee2 100644
--- a/firmware/test.cpp
+++ b/firmware/test.cpp
@@ -29,8 +29,6 @@ static ResponseTest test_discovery() {
     ResponseTest resp;
     resp.pass = true;
 
-    w6300::set_socket_dest_mac(test_socket, picomap_discovery_mac);
-
     auto req = encode_request(0, RequestInfo{});
     auto send_result = w6300::send(test_socket, std::span<const uint8_t>{req});
     if (!send_result) {
diff --git a/firmware/w6300/w6300.cpp b/firmware/w6300/w6300.cpp
index 8c706cb..02da159 100644
--- a/firmware/w6300/w6300.cpp
+++ b/firmware/w6300/w6300.cpp
@@ -272,7 +272,6 @@ constexpr uint32_t REG_SN_CR(uint8_t n)      { return (0x0010 << 8) + SREG_BLOCK
 constexpr uint32_t REG_SN_IR(uint8_t n)      { return (0x0020 << 8) + SREG_BLOCK(n); }
 constexpr uint32_t REG_SN_IRCLR(uint8_t n)   { return (0x0028 << 8) + SREG_BLOCK(n); }
 constexpr uint32_t REG_SN_SR(uint8_t n)      { return (0x0030 << 8) + SREG_BLOCK(n); }
-constexpr uint32_t REG_SN_DHAR(uint8_t n)    { return (0x0118 << 8) + SREG_BLOCK(n); }
 constexpr uint32_t REG_SN_MR2(uint8_t n)     { return (0x0144 << 8) + SREG_BLOCK(n); }
 constexpr uint32_t REG_SN_TX_BSR(uint8_t n)  { return (0x0200 << 8) + SREG_BLOCK(n); }
 constexpr uint32_t REG_SN_TX_FSR(uint8_t n)  { return (0x0204 << 8) + SREG_BLOCK(n); }
@@ -339,7 +338,6 @@ uint8_t get_sn_ir(uint8_t sn) { return reg_read(REG_SN_IR(sn)); }
 void set_sn_irclr(uint8_t sn, uint8_t v) { reg_write(REG_SN_IRCLR(sn), v); }
 void set_sn_ir(uint8_t sn, uint8_t v) { set_sn_irclr(sn, v); }
 uint8_t get_sn_sr(uint8_t sn) { return reg_read(REG_SN_SR(sn)); }
-void set_sn_dhar(uint8_t sn, uint8_t* v) { reg_write_buf(REG_SN_DHAR(sn), v, 6); }
 void set_sn_mr2(uint8_t sn, uint8_t v) { reg_write(REG_SN_MR2(sn), v); }
 void set_sn_tx_bsr(uint8_t sn, uint8_t v) { reg_write(REG_SN_TX_BSR(sn), v); }
 void set_sn_txbuf_size(uint8_t sn, uint8_t v) { set_sn_tx_bsr(sn, v); }
@@ -475,9 +473,7 @@ uint8_t sock_pack_info[sock_count] = {0,};
 
 #define FAIL(e) return std::unexpected(sock_error::e)
 #define CHECK_SOCKNUM()   do { if(sn >= sock_count) FAIL(sock_num); } while(0)
-#define CHECK_SOCKMODE(mode)  do { if((get_sn_mr(sn) & 0x0F) != mode) FAIL(sock_mode); } while(0)
 #define CHECK_SOCKDATA()  do { if(len == 0) FAIL(data_len); } while(0)
-#define CHECK_IPZERO(addr, addrlen) do { uint16_t ipzero=0; for(uint8_t i=0; i<addrlen; i++) ipzero += (uint16_t)addr[i]; if(ipzero == 0) FAIL(ip_invalid); } while(0)
 
 std::expected<void, sock_error> close(socket_id sid) {
     uint8_t sn = static_cast<uint8_t>(sid);
@@ -522,7 +518,6 @@ std::expected<socket_id, sock_error> open_socket(socket_id sid, protocol proto,
     set_sn_cr(sn, SN_CR_OPEN);
     while (get_sn_cr(sn));
     sock_io_mode_bits &= ~(1 << sn);
-    sock_io_mode_bits |= ((fl & (static_cast<uint8_t>(sock_flag::io_nonblock) >> 3)) << sn);
     sock_is_sending &= ~(1 << sn);
     sock_remained_size[sn] = 0;
     sock_pack_info[sn] = PACK_COMPLETED;
@@ -650,9 +645,6 @@ std::expected<void, sock_error> set_socket_io_mode(socket_id sid, sock_io_mode m
     return {};
 }
 
-void set_socket_dest_mac(socket_id sid, const std::array<uint8_t, 6>& mac) {
-    set_sn_dhar(static_cast<uint8_t>(sid), const_cast<uint8_t*>(mac.data()));
-}
 
 uint16_t get_socket_recv_buf(socket_id sid) {
     return get_sn_rx_rsr(static_cast<uint8_t>(sid));
diff --git a/firmware/w6300/w6300.h b/firmware/w6300/w6300.h
index 60c1a0d..0764472 100644
--- a/firmware/w6300/w6300.h
+++ b/firmware/w6300/w6300.h
@@ -13,55 +13,21 @@ enum class socket_id : uint8_t {};
 enum class sock_error : int16_t {
     busy           =     0,
     sock_num       =    -1,
-    sock_opt       =    -2,
-    sock_init      =    -3,
     sock_closed    =    -4,
     sock_mode      =    -5,
-    sock_flag      =    -6,
-    sock_status    =    -7,
     arg            =   -10,
-    port_zero      =   -11,
-    ip_invalid     =   -12,
     timeout        =   -13,
     data_len       =   -14,
-    buffer         =   -15,
     fatal_packlen  = -1001,
 };
 
 enum class protocol : uint8_t {
-    tcp       = 0x01,
-    udp       = 0x02,
-    ipraw     = 0x03,
     macraw    = 0x07,
-    tcp6      = 0x09,
-    udp6      = 0x0A,
-    ipraw6    = 0x0B,
-    tcp_dual  = 0x0D,
-    udp_dual  = 0x0E,
 };
 
 enum class sock_flag : uint8_t {
     none            = 0,
-    multi_enable    = 1 << 7,
-    ether_own       = 1 << 7,
-    broad_block     = 1 << 6,
-    tcp_fpsh        = 1 << 6,
-    tcp_nodelay     = 1 << 5,
-    igmp_ver2       = 1 << 5,
-    solicit_block   = 1 << 5,
-    ether_multi4b   = 1 << 5,
-    uni_block       = 1 << 4,
-    ether_multi6b   = 1 << 4,
-    force_arp       = 1 << 0,
-    dha_manual      = 1 << 1,
-    io_nonblock     = 1 << 3,
 };
-constexpr sock_flag operator|(sock_flag a, sock_flag b) {
-    return static_cast<sock_flag>(static_cast<uint8_t>(a) | static_cast<uint8_t>(b));
-}
-constexpr uint8_t operator&(sock_flag a, sock_flag b) {
-    return static_cast<uint8_t>(a) & static_cast<uint8_t>(b);
-}
 
 enum class sock_io_mode : uint8_t {
     block    = 0,
@@ -93,7 +59,6 @@ std::expected<uint16_t, sock_error> send(socket_id sn, std::span<const uint8_t>
 std::expected<uint16_t, sock_error> recv(socket_id sn, std::span<uint8_t> buf);
 
 std::expected<void, sock_error> set_socket_io_mode(socket_id sn, sock_io_mode mode);
-void set_socket_dest_mac(socket_id sn, const std::array<uint8_t, 6>& mac);
 uint16_t get_socket_recv_buf(socket_id sn);
 
 } // namespace w6300