Compile And Run Your Code Online Using CodePad

Have you ever been in a situation where you want to desperately try out a piece of code to see what will be the output of it; but are running here and there just to get a machine which has an installed compiler/environment for the same. This could happen when eg you are not in office and just have a eureka about your code OR suddenly want to try out some small change. How about a web service where you could type, compile and run your code and see what….. Read More

Ostinato – Free Ethernet Packet Generator For Windows And Linux

Hey I need to send a IP packet with destination address 172.26.57.86 and mac address 00:11:22:33:44:55 for doing some protocol testing. What should I do? Hmmm may be capture a similar packet in ethereal, modify the contents and send it out using some tool. OK — but what about checksums and all — how to make sure they are re-computed. Hmmm In that case — use Ixia/Smartbits — they will do the job for you OK — but the ports are limited and I wont get one just for sending….. Read More

Decode Packet Hexdumps using Packet Dump Decode(PDD)

00 13 72 8c be e1 00 90 1a 42 85 10 81 00 00 02 08 00 45 00 00 28 83 e5 40 00 7e 06 37 b7 7a a0 0b 2f 7a a0 40 c4 0e 99 01 bd ef cf 3c 3e bd 6a eb 69 50 10 fb 09 8e 5e 00 00 00 00 00 00 00 00 “Hmph. Another packet dump…” “Ok, what kind of packet is it? Let me see — offset 12, 2 bytes is 8100 ok it is a VLAN….. Read More

Find unique packet lengths from a Wireshark dump using Tshark

Some days back, I had a requirement to identify the unique packet lengths present in a Wireshark dump. As an example,  lets say the dump contains 5000 packets captured in all. Out of these lets say 4000 packets are of size 64 bytes and 1000 packets are of size 100 bytes. I am not interested in the number 4000/1000 — I only want the information that the total number of unique packet lengths present in the dump are 2 which are 64 and 100 bytes respectively. Normally, I would manually….. Read More