IP Addressing and Subnetting
Logical Addressing
IP addresses
IP addresses identify interfaces at layer so packets can move across multiple networks. Routers examine destination IPs to choose the next hop.
CIDR
Classless Inter-Domain Routing uses notation like or to describe network prefixes and host bits.
IPv4 and IPv6
| Property | IPv4 | IPv6 |
|---|---|---|
| Address size | bits | bits |
| Notation | Dotted decimal | Hexadecimal colon notation |
| Broadcast | Supported | No native broadcast |
| Typical benefit | Compact and familiar | Huge address space and better autoconfiguration |
In CIDR notation, what does the prefix length indicate?
A /24 means the first 24 bits identify the network, leaving the rest for host addresses.
Correct answer: How many bits belong to the network portion
What is the usable host range in the IPv4 subnet 192.168.1.0/24?
The .0 address is the network address and .255 is the broadcast address in a /24.
Correct answer: 192.168.1.1 to 192.168.1.254
Subnetting Logic
Why subnet
Subnetting divides a larger block into smaller ones to conserve addresses, reduce broadcast scope, and organize networks by department, function, or location.
Subnetting workflow
-
1
Step 1: Determine how many host addresses are needed.
-
2
Step 2: Choose the smallest power-of-two block that fits.
-
3
Step 3: Convert that size into a prefix length.
-
4
Step 4: Identify network, broadcast, and usable host range.
Which IPv6 feature is used to assign addresses automatically within a local network?
Stateless Address Autoconfiguration, or SLAAC, allows hosts to generate IPv6 addresses using router advertisements.
Correct answer: SLAAC
Why is IPv6 especially useful for modern internet-scale networks?
IPv6's -bit space supports more devices and simpler end-to-end addressing.
Correct answer: It provides a vastly larger address space and reduces reliance on address exhaustion workarounds