diff --git a/rtl/udp.v b/rtl/udp.v
index 22b0a0a2..24ed0ab2 100644
--- a/rtl/udp.v
+++ b/rtl/udp.v
@@ -109,7 +109,6 @@ module udp #
     input  wire [2:0]  input_udp_ip_flags,
     input  wire [12:0] input_udp_ip_fragment_offset,
     input  wire [7:0]  input_udp_ip_ttl,
-    input  wire [7:0]  input_udp_ip_protocol,
     input  wire [15:0] input_udp_ip_header_checksum,
     input  wire [31:0] input_udp_ip_source_ip,
     input  wire [31:0] input_udp_ip_dest_ip,
@@ -177,7 +176,6 @@ wire [15:0] tx_udp_ip_identification;
 wire [2:0]  tx_udp_ip_flags;
 wire [12:0] tx_udp_ip_fragment_offset;
 wire [7:0]  tx_udp_ip_ttl;
-wire [7:0]  tx_udp_ip_protocol;
 wire [15:0] tx_udp_ip_header_checksum;
 wire [31:0] tx_udp_ip_source_ip;
 wire [31:0] tx_udp_ip_dest_ip;
@@ -278,13 +276,12 @@ if (CHECKSUM_ENABLE) begin
         .input_ip_flags(input_udp_ip_flags),
         .input_ip_fragment_offset(input_udp_ip_fragment_offset),
         .input_ip_ttl(input_udp_ip_ttl),
-        .input_ip_protocol(input_udp_ip_protocol),
+        .input_ip_protocol(0),
         .input_ip_header_checksum(input_udp_ip_header_checksum),
         .input_ip_source_ip(input_udp_ip_source_ip),
         .input_ip_dest_ip(input_udp_ip_dest_ip),
         .input_udp_source_port(input_udp_source_port),
         .input_udp_dest_port(input_udp_dest_port),
-        .input_udp_length(input_udp_length),
         .input_udp_checksum(input_udp_checksum),
         .input_udp_payload_tdata(input_udp_payload_tdata),
         .input_udp_payload_tvalid(input_udp_payload_tvalid),
@@ -306,7 +303,7 @@ if (CHECKSUM_ENABLE) begin
         .output_ip_flags(tx_udp_ip_flags),
         .output_ip_fragment_offset(tx_udp_ip_fragment_offset),
         .output_ip_ttl(tx_udp_ip_ttl),
-        .output_ip_protocol(tx_udp_ip_protocol),
+        .output_ip_protocol(),
         .output_ip_header_checksum(tx_udp_ip_header_checksum),
         .output_ip_source_ip(tx_udp_ip_source_ip),
         .output_ip_dest_ip(tx_udp_ip_dest_ip),
@@ -336,7 +333,6 @@ end else begin
     assign tx_udp_ip_flags = input_udp_ip_flags;
     assign tx_udp_ip_fragment_offset = input_udp_ip_fragment_offset;
     assign tx_udp_ip_ttl = input_udp_ip_ttl;
-    assign tx_udp_ip_protocol = input_udp_ip_protocol;
     assign tx_udp_ip_header_checksum = input_udp_ip_header_checksum;
     assign tx_udp_ip_source_ip = input_udp_ip_source_ip;
     assign tx_udp_ip_dest_ip = input_udp_ip_dest_ip;
@@ -372,7 +368,7 @@ udp_ip_tx_inst (
     .input_ip_flags(tx_udp_ip_flags),
     .input_ip_fragment_offset(tx_udp_ip_fragment_offset),
     .input_ip_ttl(tx_udp_ip_ttl),
-    .input_ip_protocol(tx_udp_ip_protocol),
+    .input_ip_protocol(8'h11),
     .input_ip_header_checksum(tx_udp_ip_header_checksum),
     .input_ip_source_ip(tx_udp_ip_source_ip),
     .input_ip_dest_ip(tx_udp_ip_dest_ip),
diff --git a/rtl/udp_64.v b/rtl/udp_64.v
index f90d5334..c0c90ea4 100644
--- a/rtl/udp_64.v
+++ b/rtl/udp_64.v
@@ -111,7 +111,6 @@ module udp_64 #
     input  wire [2:0]  input_udp_ip_flags,
     input  wire [12:0] input_udp_ip_fragment_offset,
     input  wire [7:0]  input_udp_ip_ttl,
-    input  wire [7:0]  input_udp_ip_protocol,
     input  wire [15:0] input_udp_ip_header_checksum,
     input  wire [31:0] input_udp_ip_source_ip,
     input  wire [31:0] input_udp_ip_dest_ip,
@@ -181,7 +180,6 @@ wire [15:0] tx_udp_ip_identification;
 wire [2:0]  tx_udp_ip_flags;
 wire [12:0] tx_udp_ip_fragment_offset;
 wire [7:0]  tx_udp_ip_ttl;
-wire [7:0]  tx_udp_ip_protocol;
 wire [15:0] tx_udp_ip_header_checksum;
 wire [31:0] tx_udp_ip_source_ip;
 wire [31:0] tx_udp_ip_dest_ip;
@@ -285,13 +283,12 @@ if (CHECKSUM_ENABLE) begin
         .input_ip_flags(input_udp_ip_flags),
         .input_ip_fragment_offset(input_udp_ip_fragment_offset),
         .input_ip_ttl(input_udp_ip_ttl),
-        .input_ip_protocol(input_udp_ip_protocol),
+        .input_ip_protocol(0),
         .input_ip_header_checksum(input_udp_ip_header_checksum),
         .input_ip_source_ip(input_udp_ip_source_ip),
         .input_ip_dest_ip(input_udp_ip_dest_ip),
         .input_udp_source_port(input_udp_source_port),
         .input_udp_dest_port(input_udp_dest_port),
-        .input_udp_length(input_udp_length),
         .input_udp_checksum(input_udp_checksum),
         .input_udp_payload_tdata(input_udp_payload_tdata),
         .input_udp_payload_tkeep(input_udp_payload_tkeep),
@@ -314,7 +311,6 @@ if (CHECKSUM_ENABLE) begin
         .output_ip_flags(tx_udp_ip_flags),
         .output_ip_fragment_offset(tx_udp_ip_fragment_offset),
         .output_ip_ttl(tx_udp_ip_ttl),
-        .output_ip_protocol(tx_udp_ip_protocol),
         .output_ip_header_checksum(tx_udp_ip_header_checksum),
         .output_ip_source_ip(tx_udp_ip_source_ip),
         .output_ip_dest_ip(tx_udp_ip_dest_ip),
@@ -345,7 +341,6 @@ end else begin
     assign tx_udp_ip_flags = input_udp_ip_flags;
     assign tx_udp_ip_fragment_offset = input_udp_ip_fragment_offset;
     assign tx_udp_ip_ttl = input_udp_ip_ttl;
-    assign tx_udp_ip_protocol = input_udp_ip_protocol;
     assign tx_udp_ip_header_checksum = input_udp_ip_header_checksum;
     assign tx_udp_ip_source_ip = input_udp_ip_source_ip;
     assign tx_udp_ip_dest_ip = input_udp_ip_dest_ip;
@@ -382,7 +377,7 @@ udp_ip_tx_64_inst (
     .input_ip_flags(tx_udp_ip_flags),
     .input_ip_fragment_offset(tx_udp_ip_fragment_offset),
     .input_ip_ttl(tx_udp_ip_ttl),
-    .input_ip_protocol(tx_udp_ip_protocol),
+    .input_ip_protocol(8'h11),
     .input_ip_header_checksum(tx_udp_ip_header_checksum),
     .input_ip_source_ip(tx_udp_ip_source_ip),
     .input_ip_dest_ip(tx_udp_ip_dest_ip),
diff --git a/tb/test_udp.py b/tb/test_udp.py
index 5f1760b0..9f56e2bd 100755
--- a/tb/test_udp.py
+++ b/tb/test_udp.py
@@ -109,7 +109,6 @@ def dut_udp(clk,
             input_udp_ip_flags,
             input_udp_ip_fragment_offset,
             input_udp_ip_ttl,
-            input_udp_ip_protocol,
             input_udp_ip_header_checksum,
             input_udp_ip_source_ip,
             input_udp_ip_dest_ip,
@@ -225,7 +224,6 @@ def dut_udp(clk,
                 input_udp_ip_flags=input_udp_ip_flags,
                 input_udp_ip_fragment_offset=input_udp_ip_fragment_offset,
                 input_udp_ip_ttl=input_udp_ip_ttl,
-                input_udp_ip_protocol=input_udp_ip_protocol,
                 input_udp_ip_header_checksum=input_udp_ip_header_checksum,
                 input_udp_ip_source_ip=input_udp_ip_source_ip,
                 input_udp_ip_dest_ip=input_udp_ip_dest_ip,
@@ -313,7 +311,6 @@ def bench():
     input_udp_ip_flags = Signal(intbv(0)[3:])
     input_udp_ip_fragment_offset = Signal(intbv(0)[13:])
     input_udp_ip_ttl = Signal(intbv(0)[8:])
-    input_udp_ip_protocol = Signal(intbv(0)[8:])
     input_udp_ip_header_checksum = Signal(intbv(0)[16:])
     input_udp_ip_source_ip = Signal(intbv(0)[32:])
     input_udp_ip_dest_ip = Signal(intbv(0)[32:])
@@ -470,7 +467,6 @@ def bench():
                                        ip_flags=input_udp_ip_flags,
                                        ip_fragment_offset=input_udp_ip_fragment_offset,
                                        ip_ttl=input_udp_ip_ttl,
-                                       ip_protocol=input_udp_ip_protocol,
                                        ip_header_checksum=input_udp_ip_header_checksum,
                                        ip_source_ip=input_udp_ip_source_ip,
                                        ip_dest_ip=input_udp_ip_dest_ip,
@@ -586,7 +582,6 @@ def bench():
                   input_udp_ip_flags,
                   input_udp_ip_fragment_offset,
                   input_udp_ip_ttl,
-                  input_udp_ip_protocol,
                   input_udp_ip_header_checksum,
                   input_udp_ip_source_ip,
                   input_udp_ip_dest_ip,
diff --git a/tb/test_udp.v b/tb/test_udp.v
index 278552e2..e6ba1c71 100644
--- a/tb/test_udp.v
+++ b/tb/test_udp.v
@@ -71,7 +71,6 @@ reg [15:0] input_udp_ip_identification = 0;
 reg [2:0] input_udp_ip_flags = 0;
 reg [12:0] input_udp_ip_fragment_offset = 0;
 reg [7:0] input_udp_ip_ttl = 0;
-reg [7:0] input_udp_ip_protocol = 0;
 reg [15:0] input_udp_ip_header_checksum = 0;
 reg [31:0] input_udp_ip_source_ip = 0;
 reg [31:0] input_udp_ip_dest_ip = 0;
@@ -183,7 +182,6 @@ initial begin
                 input_udp_ip_flags,
                 input_udp_ip_fragment_offset,
                 input_udp_ip_ttl,
-                input_udp_ip_protocol,
                 input_udp_ip_header_checksum,
                 input_udp_ip_source_ip,
                 input_udp_ip_dest_ip,
@@ -330,7 +328,6 @@ UUT (
     .input_udp_ip_flags(input_udp_ip_flags),
     .input_udp_ip_fragment_offset(input_udp_ip_fragment_offset),
     .input_udp_ip_ttl(input_udp_ip_ttl),
-    .input_udp_ip_protocol(input_udp_ip_protocol),
     .input_udp_ip_header_checksum(input_udp_ip_header_checksum),
     .input_udp_ip_source_ip(input_udp_ip_source_ip),
     .input_udp_ip_dest_ip(input_udp_ip_dest_ip),
diff --git a/tb/test_udp_64.py b/tb/test_udp_64.py
index 3b4e6d1c..dd1c54d1 100755
--- a/tb/test_udp_64.py
+++ b/tb/test_udp_64.py
@@ -111,7 +111,6 @@ def dut_udp(clk,
             input_udp_ip_flags,
             input_udp_ip_fragment_offset,
             input_udp_ip_ttl,
-            input_udp_ip_protocol,
             input_udp_ip_header_checksum,
             input_udp_ip_source_ip,
             input_udp_ip_dest_ip,
@@ -231,7 +230,6 @@ def dut_udp(clk,
                 input_udp_ip_flags=input_udp_ip_flags,
                 input_udp_ip_fragment_offset=input_udp_ip_fragment_offset,
                 input_udp_ip_ttl=input_udp_ip_ttl,
-                input_udp_ip_protocol=input_udp_ip_protocol,
                 input_udp_ip_header_checksum=input_udp_ip_header_checksum,
                 input_udp_ip_source_ip=input_udp_ip_source_ip,
                 input_udp_ip_dest_ip=input_udp_ip_dest_ip,
@@ -322,7 +320,6 @@ def bench():
     input_udp_ip_flags = Signal(intbv(0)[3:])
     input_udp_ip_fragment_offset = Signal(intbv(0)[13:])
     input_udp_ip_ttl = Signal(intbv(0)[8:])
-    input_udp_ip_protocol = Signal(intbv(0)[8:])
     input_udp_ip_header_checksum = Signal(intbv(0)[16:])
     input_udp_ip_source_ip = Signal(intbv(0)[32:])
     input_udp_ip_dest_ip = Signal(intbv(0)[32:])
@@ -484,7 +481,6 @@ def bench():
                                        ip_flags=input_udp_ip_flags,
                                        ip_fragment_offset=input_udp_ip_fragment_offset,
                                        ip_ttl=input_udp_ip_ttl,
-                                       ip_protocol=input_udp_ip_protocol,
                                        ip_header_checksum=input_udp_ip_header_checksum,
                                        ip_source_ip=input_udp_ip_source_ip,
                                        ip_dest_ip=input_udp_ip_dest_ip,
@@ -604,7 +600,6 @@ def bench():
                   input_udp_ip_flags,
                   input_udp_ip_fragment_offset,
                   input_udp_ip_ttl,
-                  input_udp_ip_protocol,
                   input_udp_ip_header_checksum,
                   input_udp_ip_source_ip,
                   input_udp_ip_dest_ip,
diff --git a/tb/test_udp_64.v b/tb/test_udp_64.v
index dbce9b8c..556324b4 100644
--- a/tb/test_udp_64.v
+++ b/tb/test_udp_64.v
@@ -72,7 +72,6 @@ reg [15:0] input_udp_ip_identification = 0;
 reg [2:0] input_udp_ip_flags = 0;
 reg [12:0] input_udp_ip_fragment_offset = 0;
 reg [7:0] input_udp_ip_ttl = 0;
-reg [7:0] input_udp_ip_protocol = 0;
 reg [15:0] input_udp_ip_header_checksum = 0;
 reg [31:0] input_udp_ip_source_ip = 0;
 reg [31:0] input_udp_ip_dest_ip = 0;
@@ -188,7 +187,6 @@ initial begin
                 input_udp_ip_flags,
                 input_udp_ip_fragment_offset,
                 input_udp_ip_ttl,
-                input_udp_ip_protocol,
                 input_udp_ip_header_checksum,
                 input_udp_ip_source_ip,
                 input_udp_ip_dest_ip,
@@ -340,7 +338,6 @@ UUT (
     .input_udp_ip_flags(input_udp_ip_flags),
     .input_udp_ip_fragment_offset(input_udp_ip_fragment_offset),
     .input_udp_ip_ttl(input_udp_ip_ttl),
-    .input_udp_ip_protocol(input_udp_ip_protocol),
     .input_udp_ip_header_checksum(input_udp_ip_header_checksum),
     .input_udp_ip_source_ip(input_udp_ip_source_ip),
     .input_udp_ip_dest_ip(input_udp_ip_dest_ip),