Lab 04: Wireshark Lab of DNS and HTTP

Part 1: DNS Protocol

Usage of ipconfig:

ipconfig /all
ipconfig /displaydns
ipconfig /flushdns

Resource Records (RRs) in DNS distributed database:

(Name, Value, Type, TTL)

Usage of nslookup

nslookup [-option] name [server]

nslookup www.eecs.mit.edu
nslookup -type=A www.eecs.mit.edu
nslookup -type=NS mit.edu
nslookup -type=CNAME www.eecs.mit.edu name_of_server

Part 2: HTTP Protocol

Web Caching

If-modified-since / Etag

Wireshark Lab: HTTP

Please download Wireshark_HTTP_v6.1.pdf for the instruction of this lab session.

Part 3: Miscellaneous

Filters for Wireshark

Find the address of the webserver:

http.host=="gaia.cs.umass.edu"

Locate specific http connection:

ip.addr==xxx.xxx.xxx.xxx && http