Ask HN: Linux networking interview questions

13 pointsthickice2 comments

What are some good interview questions for a kernel developer in the networking area (bridging, Layer2, netfilter/iptables, IP routing, Layer 3 and TCP/UDP stack)

View on HN

Give the lifecycle of an sk_buff structure from birth (in the driver) all the way up to a user's socket read syscall. Familiarity with various layers and how the TCP state machine works are a given. Do they know any dark corners? IP routing in linux can do some incredible things, do they know anything about that.

Sources:

http://vger.kernel.org/~davem/skb.html

https://people.cs.clemson.edu/~westall/853/notes/skbuff.pdf

If you're good enough to read the kernel code yourself take a look at a wifi or ethernet driver with them and have them explain what's going on all the way up the stack. Even if you don't know that much you'll be able to smell BS if they don't.

thanks!

Reply on news.ycombinator.com