diff --git a/hw/super6502_fpga/src/sub/network_processor/src/tcp_packet_generator.sv b/hw/super6502_fpga/src/sub/network_processor/src/tcp_packet_generator.sv
index da36efe..4f79837 100644
--- a/hw/super6502_fpga/src/sub/network_processor/src/tcp_packet_generator.sv
+++ b/hw/super6502_fpga/src/sub/network_processor/src/tcp_packet_generator.sv
@@ -67,6 +67,9 @@ logic data_checksum_clear;
 logic [31:0] data_checksum_data;
 logic [15:0] data_checksum_final;
 
+logic [31:0] src_ip, dst_ip_next;
+logic [31:0] dst_ip, src_ip_next;
+
 checksum_calc u_header_checksum_calc(
     .i_rst      (i_rst),
     .i_clk      (i_clk),
@@ -83,11 +86,15 @@ always_ff @(posedge i_clk) begin
         checksum_counter <= '0;
         state <= IDLE;
         data_expand <= '0;
+        src_ip <= '0;
+        dst_ip <= '0;
     end else begin
         counter <= counter_next;
         checksum_counter <= checksum_counter_next;
         state <= state_next;
         data_expand <= data_expand_next;
+        src_ip <= src_ip_next;
+        dst_ip <= dst_ip_next;
     end
 end
 
@@ -125,6 +132,8 @@ always_comb begin
 
     data_expand_next = data_expand;
 
+    src_ip_next = src_ip;
+    dst_ip_next = dst_ip;
     case (state)
 
         IDLE: begin
@@ -142,6 +151,9 @@ always_comb begin
                 m_ip.ip_source_ip   = i_src_ip;
                 m_ip.ip_dest_ip     = i_dst_ip;
 
+                src_ip_next = i_src_ip;
+                dst_ip_next = i_dst_ip;
+
                 if (m_ip.ip_hdr_ready) begin
                     if (i_no_data) begin
                         state_next = HEADER;
@@ -181,9 +193,9 @@ always_comb begin
             end
 
             case (checksum_counter)
-                0: checksum_data = m_ip.ip_source_ip;
-                1: checksum_data = m_ip.ip_dest_ip;
-                2: checksum_data = {8'b0, m_ip.ip_protocol, (i_ip_len - 16'd20)}; // tcp length, not IP length
+                0: checksum_data = src_ip;
+                1: checksum_data = dst_ip;
+                2: checksum_data = {8'b0, 8'h6, (i_ip_len - 16'd20)}; // tcp length, not IP length
                 3: checksum_data = {i_source_port, i_dest_port};
                 4: checksum_data = i_seq_number;
                 5: checksum_data = i_ack_number;
diff --git a/hw/super6502_fpga/src/sub/network_processor/src/tcp_parser.sv b/hw/super6502_fpga/src/sub/network_processor/src/tcp_parser.sv
index cd368da..73a26ee 100644
--- a/hw/super6502_fpga/src/sub/network_processor/src/tcp_parser.sv
+++ b/hw/super6502_fpga/src/sub/network_processor/src/tcp_parser.sv
@@ -110,6 +110,7 @@ always_comb begin
         end
 
         PAYLOAD: begin
+            s_ip.ip_payload_axis_tready = '1;
             if (s_ip.ip_payload_axis_tlast) begin
                 counter_next = '0;
                 state_next = HEADER;