Here’s some of the new Networking for System Administrators, because while the Laserblasted Kickstarter ends today I am utterly sick of shilling it.
Think of the network as a conference room. At the physical layer you have a table and chairs. The room is a broadcast domain. Each chair is a host, with a unique MAC address.
As an IP network, the table can hold a number of chairs equal to a power of two. Each chair has a unique IP address. Two of the chairs, the top and bottom addresses, are rickety and dangerous to use. Nobody sits in the chair by the door, as that’s the default gateway.
ICMP lets you see things like “George is asleep, so he’s not answering questions.” TCP is when you pass the stack of memos to the next person and make sure the other person has them before letting go. Drop the memos and you must gather them off the floor and retransmit. UDP is when you crumple the memo into a wad and launch it at the project manager. What comes back might be the same memo, nothing, your termination notice, or a brick, depending on your meeting protocol.
Networking for System Administrators is open for sponsorships. And the Laserblasted Kickstarter closes Thursday 17 April at 8PM Eastern.