Client–Server vs. Peer‑to‑Peer
Understanding the Basics . . .
1. Protocols
When we talk about protocols, we are talking about the rules computers use to communicate.
Peer‑to‑Peer protocols
A protocol is peer‑to‑peer when all devices are equal.
There is no boss and no hierarchy.
Examples:
- TCP
- UDP
- ICMP
- ARP
In ARP, for example, there is no ARP‑server and ARP‑client.
Every device simply asks and answers as an equal peer.
On the Ethernet level, it’s the same: all devices are equal.
(BTW.: we can influence behaviour with managed switches, but the protocol itself stays equal.)
Client–Server protocols
Most application‑level protocols do use hierarchy.
One side asks (client), the other side answers (server).
Examples:
- HTTP / HTTPS (the web)
- FTP (file transfer)
- SMTP / POP3 / IMAP4 (email)
- DNS
- DHCP
/\/\ these are all client–server /\/\
Exceptions: some systems work without a central server, such as: torrent networks, some online games that connect players directly ...
Client–Server vs. Peer‑to‑Peer From a System Administrator’s View
1. Client–Server network
For a sysadmin, a client–server network means:
There is one or more central servers that manage the network.
Typical example: A Domain Controller that manages users, passwords, and permissions.
This makes the network easier to control and more secure.
2. Peer‑to‑Peer network
In a peer‑to‑peer network, each user manages their own computer. There is no central server. This was common in older systems like Windows for Workgroups.
The problem: you must create and manage users and permissions on every single machine.
Once you reach around 10 computers, the network becomes difficult to manage — causing “organised chaos”.