Networking on ZK Punk

Traceroute implementation using scapy

Wed, 28 Sep 2011 00:08:00 -0800

Traceroute Link to heading

Traceroute is a network diagnostic utility used for displaying the path taken by a packet to it’s destination. It uses the ICMP protocol to help traverse the path. Each IP packet has an 8 bit TTL field that gets decremented by every router on the path, to prevent the packet from indefinitely circulating the internet (or network). When the TTL value reaches zero an ICMP error ‘Time To Live Exceeded’ is sent back to the sender. We can use this fact to our advantage by discovering all the hops between the source and the destination.

Dropbox: LAN Sync Protocol

Sat, 10 Sep 2011 00:08:00 -0800

A year ago, I fired up wire shark on my home network to check out the packet flow of the DHCP process. I closed all my browser windows and other chat/im services, and still noticed a lot of chatter on the network. One that got my particular attention was a packet that was related to the popular service dropbox. I had not updated/edited any files recently, so was surprised to see it. I then decided to dig a little more on wire shark and with some google search came to the conclusion that it was a dropbox feature to sync data changes within the local network.

How does DHCP work?

Sat, 10 Sep 2011 00:08:00 -0800

What is DHCP ? Link to heading

DHCP is a protocol used to provide an IP address to a device. It is also used to configure additional networking related parameters on the device like subnet mask, router, domain name, and dns server.

Why DHCP ? Link to heading

DHCP stands for dynamic host configuration protocol and so allows a device to get an IP address without any manual intervention as long as the dhcp client is enabled and running on the device.