- Estimate ping time from your workstation to your local gateway? www.google.com? Server on the east coast from the west coast? Server in Europe from the west coast?
- What law(s) of physics control(s) the round trip times?
Having interviewed a lot of sysadmins, I see this trip people up, mostly because the slash/bits network notation isn't taught/documented well. The "memorize a table" approach seems to be common.
Most of them, with a bit of prompting, get that an ipv4 is 32 bits, and that a /23 means (32-23==9) 9 bits of host addresses. Most also can figure out what 111111111 is. Some remember to account for the network and broadcast address not being available for hosts.
I've recently learned that this is a bit of a trick question. How many routers are in embedded the /23? How many addresses are reserved for multicast? Are you on AWS VPC, where they reserve even a few more addresses for internal management?
All of those are good points. But a surprising number of people can't get to the starting point 2^(32-23)=512. I usually subtract 2 and say 510. No IPs are reserved for multicast. Maybe you meant broadcast?
- How many hosts are there in a /23 network?
- Estimate ping time from your workstation to your local gateway? www.google.com? Server on the east coast from the west coast? Server in Europe from the west coast?
- What law(s) of physics control(s) the round trip times?