Interview Q&A / Computer Networks

INTERVIEW Q&A · 55 QUESTIONS

Computer Networks interview questions

What happens when you open a website, TCP vs UDP, DNS and HTTP.

  1. How does DNS resolution work, step by step?

    Your device asks a recursive resolver, which checks its cache and, if needed, asks a root server, then the TLD server (like .com), then the domain's authoritative server, which returns the IP address. Every answer carries a TTL, so resolvers and devices cache it and skip most of these steps next time.

    IntermediateIn-depth4 min read
  2. What is an IP address, a subnet and CIDR notation like /24?

    An IPv4 address is a 32-bit number that identifies a device on a network. CIDR notation such as 192.168.1.0/24 says how many leading bits are the network part; the rest identify hosts. A /24 has 256 addresses (254 usable), a /16 has 65,536, and each extra bit halves the size of the subnet.

    IntermediateIn-depth4 min read