Differences in System Design Interview Topics
Common "difference" questions asked in system design interviews — comparing patterns, protocols, and architectural choices side by side.
System Design Common Differences Asked in Interview
Ipv4 vs Ipv6
+--------------------+----------------------------------------------+----------------------------------------------+ | Feature | IPv4 | IPv6 | +--------------------+----------------------------------------------+----------------------------------------------+ | Definition | Fourth version of the Internet Protocol | Sixth version of the Internet Protocol | +--------------------+----------------------------------------------+----------------------------------------------+ | Address size | Uses 32-bit addresses | Uses 128-bit addresses | +--------------------+----------------------------------------------+----------------------------------------------+ | Address format | Decimal, such as 192.168.1.1 | Hexadecimal, such as 2001:db8::1 | +--------------------+----------------------------------------------+----------------------------------------------+ | Address capacity | About 4.3 billion unique addresses | About 3.4 x 10^38 unique addresses | +--------------------+----------------------------------------------+----------------------------------------------+ | Working | Routes packets using 32-bit IP addresses | Routes packets using 128-bit IP addresses | +--------------------+----------------------------------------------+----------------------------------------------+ | Configuration | Manual setup or DHCP is commonly used | Supports SLAAC, DHCPv6, or manual setup | +--------------------+----------------------------------------------+----------------------------------------------+ | Header | Variable header of 20 to 60 bytes | Fixed 40-byte base header | +--------------------+----------------------------------------------+----------------------------------------------+ | Broadcast | Supports broadcast communication | Uses multicast instead of broadcast | +--------------------+----------------------------------------------+----------------------------------------------+ | Fragmentation | Routers and hosts can fragment packets | Only the sending host fragments packets | +--------------------+----------------------------------------------+----------------------------------------------+ | Security | IPsec support is optional | Designed with built-in IPsec support | +--------------------+----------------------------------------------+----------------------------------------------+ | NAT | Commonly uses NAT to conserve addresses | Usually avoids NAT due to vast address space | +--------------------+----------------------------------------------+----------------------------------------------+ | Key difference | Smaller address space and wider deployment | Huge address space and improved networking | +--------------------+----------------------------------------------+----------------------------------------------+ | Advantages | Mature, compatible, and widely supported | Scalable, efficient, and easier to configure | +--------------------+----------------------------------------------+----------------------------------------------+ | Disadvantages | Address shortage and heavy dependence on NAT | Limited support in some legacy systems | +--------------------+----------------------------------------------+----------------------------------------------+ | Best use cases | Existing networks and legacy applications | Modern, cloud, IoT, and large-scale networks | +--------------------+----------------------------------------------+----------------------------------------------+ | Example | 192.168.10.25 | 2001:db8:85a3::8a2e:370:7334 | +--------------------+----------------------------------------------+----------------------------------------------+