Magnet Weekly CTF — Week 7

2 min readNov 23, 2020


OK, this week was short and sweet, more of a scavenger hunt style. A much needed break from the last couple weeks which have been pretty rough.

Part 1

Question: What is the IP address of the HDFS primary node?

I went looking around the typical Linux places, but remembered we were looking for the HDFS node’s IP address so I went snooping around hadoop logs:

That was easy.

Boom, there it is:

Part 2

Question: Is the IP address on HDFS-Primary dynamically or statically assigned?

Well this was a 50/50 question, but I still wanted to be sure, so I went looking at the usual suspects. Sure enough, found this in /etc/hosts:

Answer: Statically
Note: probably could have used this as the answer to both Part 1 and Part 2, but I happened to stumble on the Hadoop logs first. Oh well.

Part 3

Question: What is the interface name for the primary HDFS node?

This one tested my skills a bit more as I wasn’t really sure where to go looking. I poked around for quite sometime and finally resorted to Googling. After a couple dead ends on StackOverflow, I saw a reference to /etc/network/interfaces. Sure enough:

And the answer is ‘ens33’

I enjoyed this style of question because it really did lead me to some Linux files I was either unfamiliar with or didn’t know they contained that information.