Reader Tomi Nousiainen sent me this sunny and relaxed greeting for Midsummer, which he allowed me to share with all of you.

(c) 2007, Tomi Nousiainen

With this picture, I too would like to wish all my other readers and warm and sunny, and above all a relaxed and enjoyable summer!

Talking about midsummer, I recently stumbled upon Val Hensons TCP/IP drinking game. The game goes like this: "Each person asks a question of the person next in line. If you get the wrong answer, drink to punish yourself. If you get the right answer, drink to celebrate. If it was a particularly good question, everyone drinks. Remember, nobody wins a drinking game." (I particularly like the - possibly unintended - educationary tone of the last sentence :-)

The questions are about TCP/IP and networking:

Q: What two ICMP types should never be blocked?
A: ICMP type 3, Destination Unreachable, especially code 4, "fragmentation needed but don't fragment bit set" (necessary for path MTU discovery) and ICMP type 11, time exceeded (so you can use traceroute from inside the network and get replies).
Credit: Arjan van de Ven

Q: What is the IANA reserved Ethernet MAC address range for IP Multicast?
A: 01:00:5e.
Credit: Rob Braun, Michael Dupuis

Val doesn't say so, but my understanding is that if you are more interested in the questions than the drinking, you qualify as a nerd?

This one is a gem, I love it how the RFC's sometimes break out of the purely technical writing tone and portray the heroes working behind the Internet. (the Internet communication protocols are standardised in Request For Comments documents)

Q: What data link layer algorithm is described by an "algorhyme" in the original paper? Extra credit for reciting the first two lines.
A: The spanning tree algorithm by Dr. Radia Perlman
A: The first two lines are: I think that I shall never see / A graph more lovely than a tree.
Credit: Christina Zeeh