WireGuard

What is WireGuard?

WireGuard is a modern, lightweight, and high-performance VPN protocol designed to create secure point-to-point connections. It uses state-of-the-art cryptography and is known for its simplicity, speed, and ease of deployment.

Why is WireGuard important?

  • Fast and Efficient – Minimal codebase and optimized performance make it faster than traditional VPNs like IPsec or OpenVPN.

  • Secure – Uses modern cryptographic primitives like Curve25519, ChaCha20, and Poly1305.

  • Cross-Platform – Works on Linux, Windows, macOS, Android, and iOS.

  • Easy to Configure – Simple configuration using public/private key pairs.

How WireGuard works (in simple steps):

  • Each device (peer) generates a public/private key pair.

  • Devices exchange public keys and configure allowed IPs.

  • A secure tunnel is established using the exchanged keys.

  • Encrypted packets are sent directly between peers using UDP.

Where is WireGuard used?

  • Remote Access VPNs for employees and developers.

  • Site-to-Site VPNs between branch offices or data centers.

  • Cloud Networking to securely connect cloud instances.

  • IoT and Embedded Devices due to its lightweight design.

  • Mobile Devices for secure and battery-efficient VPN connections.

Which OSI Layer does this protocol belong to?

WireGuard operates at the Network Layer (Layer 3) because: * It encapsulates IP packets (IPv4/IPv6) directly. * It handles routing and IP-level communication between peers. * It is protocol-agnostic and works below the transport layer.

Is WireGuard Windows specific?

  • No, WireGuard is not Windows-specific.

  • WireGuard is a cross-platform VPN protocol that supports Windows, Linux, macOS, iOS, and Android.

  • It is available as a kernel module on Linux and as a software package for other operating systems.

Is WireGuard Linux specific?

  • No, WireGuard is not Linux-specific.

  • While WireGuard was initially developed for Linux, it has since been ported to other platforms, including Windows, macOS, iOS, and Android.

  • It is natively supported as a kernel module on Linux, but it is available for other operating systems via software packages.

Which Transport Protocol is used by WireGuard?

  • WireGuard uses UDP (User Datagram Protocol) as its transport protocol.

  • UDP is preferred for its low latency and minimal overhead, making WireGuard highly efficient for VPN connections.

Which Port is used by WireGuard?

  • By default, WireGuard uses UDP port 51820.

  • This can be customized depending on the configuration, but port 51820 is the standard port for WireGuard communications.

Is WireGuard using Client-server model?

  • Yes, WireGuard uses the client-server model.

  • The WireGuard client establishes a secure, encrypted connection to a WireGuard server.

  • Once the connection is established, data is transmitted securely between the client and server.

Topics in this section,

  • In this section, you are going to learn

  • Terminology

  • Version Info

WireGuard Version

RFC

Year

Core Idea / Contribution

WireGuard Protocol

RFC 9381

2023

Official specification of the WireGuard protocol as a VPN tunneling protocol using modern cryptography.

Cryptographic Framework

N/A

2018+

Based on the Noise Protocol Framework, which defines secure key exchange and encryption.

UDP Transport

N/A

WireGuard operates over UDP (default port 51820), not defined in a separate RFC.

Linux Kernel Support

N/A (mainline)

2020

Integrated into the Linux kernel (v5.6+), improving performance and native support.

Cross-Platform Support

N/A

Ongoing

Implementations available for Windows, macOS, Android, iOS, and BSD systems

Setup

Setup

Handshake Initiation

S.No

Protocol Packets

Description

Size(Bytes)

1

Handshake Initiation

Sent by the client to initiate a secure session with the server.

~148 bytes

Message Type

Identifies this as a handshake initiation message.

1

Sender Index

Random identifier for the initiating peer.

4

Ephemeral Public Key

Used for key exchange (Curve25519).

32

Encrypted Static Public Key

Clients static public key encrypted with servers public key.

48

Encrypted Timestamp

Prevents replay attacks.

12

MACs

Message authentication codes for validation.

32 + 16

Handshake Response

S.No

Protocol Packets

Description

Size(Bytes)

2

Handshake Response

Sent by the server in response to the initiation message

~92 bytes

Message Type

Identifies this as a handshake response message

1

Sender Index

Random identifier for the responding peer

4

Receiver Index

Matches the clients sender index

4

Ephemeral Public Key

Servers ephemeral key for key exchange

32

Encrypted Empty

Used to finalize key confirmation

16

MAC

Message authentication code

16

Cookie Reply

S.No

Protocol Packets

Description

Size(Bytes)

3

Cookie Reply

Sent when a peer is under DoS attack to validate the sender

~64 bytes

Message Type

Identifies this as a cookie reply message

1

Receiver Index

Matches the sender index of the peer

4

Nonce

Random value used in encryption

24

Encrypted Cookie

Encrypted token to validate sender

32

Transport Data Packet

S.No

Protocol Packets

Description

Size(Bytes)

4

Transport Data Packet

Carries encrypted IP packets between peers after handshake

Variable

Message Type

Identifies this as a transport data message

1

Receiver Index

Identifies the receiving peer

4

Counter

Prevents replay attacks

8

Encrypted Payload

Encrypted IP packet (IPv4/IPv6)

Variable

S.no

Use Case

Description

1

Secure Remote Access

Enables employees or users to securely connect to internal networks from remote locations.

2

Site-to-Site VPN

Connects multiple office or data center networks securely over the internet.

3

Cloud Networking

Establishes secure tunnels between cloud instances or between on-prem and cloud environments.

4

Mobile VPN

Provides fast, battery-efficient VPN connections for mobile devices (Android, iOS).

5

IoT and Embedded Devices

Ideal for lightweight, secure communication between IoT devices due to its minimal codebase.

6

Developer Environments

Used by developers to securely access test environments, CI/CD pipelines, or internal APIs.

7

Privacy Protection

Encrypts internet traffic to protect user privacy on public or untrusted networks.

8

Mesh Networking

Supports peer-to-peer encrypted communication in decentralized or mesh network setups.

S.no

Feature

Description

1

Modern Cryptography

Uses state-of-the-art cryptographic primitives like Curve25519,ChaCha20, Poly1305, BLAKE2s.

2

Simplicity

Minimal codebase (~4,000 lines), making it easier to audit and maintain.

3

High Performance

Designed for speed and low latency, outperforming traditional VPN protocols like IPsec and OpenVPN.

4

Stateless Design

No connection tracking; each packet is independent, improving security and scalability.

5

UDP-Based Transport

Operates over UDP, reducing overhead and improving NAT traversal.

6

IP Layer Tunneling

Encapsulates IP packets (IPv4/IPv6), functioning at OSI Layer 3.

7

Key-Based Authentication

Uses public/private key pairs for peer authentication instead of usernames/passwords.

8

Roaming Support

Seamlessly handles IP address changes without dropping the connection.

9

Cross-Platform Compatibility

Available on Linux, Windows, macOS, Android, iOS, and embedded systems.

10

Easy Configuration

Simple configuration using a single file per peer with clear syntax.

Modern Cryptography - Testcases

#

Test Case

Description

Expected Result

1

Interface Initialization

Start WireGuard interface

Interface is up and running

2

Key Generation

Generate private/public key pair

Keys are generated successfully

3

Config File Validation

Load valid config file

No errors, config accepted

4

Invalid Config File

Load malformed config

Error or rejection

5

Peer Addition

Add a peer to config

Peer added successfully

6

Handshake Initiation

Initiate handshake with peer

Handshake completes

7

Handshake Failure

Use wrong public key

Handshake fails

8

Data Transmission

Send encrypted data

Data received and decrypted

9

Replay Attack Test

Replay old packet

Packet dropped

10

Packet Tampering

Modify encrypted packet

Packet rejected

11

MTU Size Test

Send large packets

Packets fragmented or dropped

12

Interface Down

Bring interface down

Traffic stops

13

Interface Up

Bring interface up

Traffic resumes

14

Persistent Keepalive

Enable keepalive

Periodic packets sent

15

No Keepalive

Disable keepalive

No periodic packets

16

IP Address Assignment

Assign IP to interface

IP assigned successfully

17

Route Injection

Add route via WireGuard

Route added

18

Route Removal

Remove route

Route removed

19

DNS Resolution

Use DNS over VPN

DNS queries resolved

20

DNS Leak Test

Check for DNS leaks

No leaks detected

21

IPv6 Support

Use IPv6 addresses

IPv6 traffic routed

22

IPv4 Support

Use IPv4 addresses

IPv4 traffic routed

23

Multiple Peers

Add multiple peers

All peers reachable

24

Peer Removal

Remove a peer

Peer removed

25

Interface Restart

Restart WireGuard

Interface reconnects

26

Port Change

Change listening port

New port active

27

Firewall Compatibility

Use with firewall rules

Traffic allowed/blocked as expected

28

NAT Traversal

Connect behind NAT

Connection succeeds

29

Roaming Support

Change client IP

Connection persists

30

Endpoint Update

Peer updates endpoint

New endpoint accepted

31

AllowedIPs Filtering

Restrict IPs per peer

Only allowed IPs routed

32

Invalid AllowedIPs

Use invalid IP range

Config error

33

Pre-shared Key

Add PSK to peer config

Extra encryption layer added

34

No Pre-shared Key

Remove PSK

Connection still works

35

Interface Statistics

Check tx/rx stats

Stats increment with traffic

36

Log Monitoring

Monitor logs

Handshake and traffic logs visible

37

Interface Persistence

Reboot system

Interface auto-starts

38

Config Reload

Reload config without restart

Changes applied

39

Performance Benchmark

Measure throughput

Meets expected bandwidth

40

Latency Test

Measure ping over VPN

Acceptable latency

41

Packet Loss Simulation

Drop packets

Connection handles loss

42

Encryption Validation

Inspect encryption method

Uses ChaCha20-Poly1305

43

Key Rotation

Rotate keys manually

New keys accepted

44

Key Expiry Handling

Use expired keys

Connection fails

45

Time Sync Dependency

Desync system clock

Handshake fails

46

Mobile Device Support

Use on Android/iOS

VPN connects

47

OS Compatibility

Test on Linux/Windows/macOS

VPN works on all

48

Config Import/Export

Import/export config files

Files parsed correctly

49

Interface Isolation

Block non-VPN traffic

Only VPN traffic allowed

50

Kill Switch

Enable kill switch

Traffic blocked if VPN drops

Simplicity - Testcases

#

Test Case

Description

Expected Result

1

Minimal Config File

Use only required fields in config

VPN connects successfully

2

Quick Setup

Complete setup in under 5 minutes

VPN operational within time

3

One-Line Key Generation

Generate keys with a single command

Keys generated instantly

4

Simple Peer Addition

Add peer with minimal fields

Peer connects successfully

5

No GUI Required

Configure via CLI only

Fully functional VPN

6

Easy Interface Start

Use wg-quick up

Interface starts without error

7

Easy Interface Stop

Use wg-quick down

Interface stops cleanly

8

Simple Status Check

Use wg to check status

Clear and concise output

9

Minimal Dependencies

Install without extra packages

Installation succeeds

10

Lightweight Binary

Check binary size

Small footprint (<1MB)

11

Simple Routing Setup

Add route via config

Route works as expected

12

No Daemon Needed

Run without background service

VPN functions normally

13

Easy Config Reload

Reload config without restart

Changes applied instantly

14

Simple Log Output

View logs for interface

Logs are readable and minimal

15

Clear Error Messages

Trigger config error

Error message is understandable

16

Simple IP Assignment

Assign IP in config

IP assigned correctly

17

Easy Port Change

Change listening port

New port active

18

Simple NAT Traversal

Connect behind NAT

Connection succeeds

19

Minimal Peer Config

Use only public key and endpoint

Peer connects

20

Easy Key Rotation

Replace keys manually

New keys accepted

21

Simple DNS Setup

Add DNS in config

DNS queries routed through VPN

22

No Extra Encryption Setup

Use built-in ChaCha20

Encryption works out of the box

23

Simple IPv6 Support

Add IPv6 address in config

IPv6 traffic routed

24

Easy IPv4 Support

Add IPv4 address in config

IPv4 traffic routed

25

Simple Peer Removal

Remove peer from config

Peer disconnected

26

Easy Interface Restart

Restart interface with one command

Interface reconnects

27

Simple Config Sharing

Share config via text file

Peer connects using shared config

28

No GUI Debugging

Troubleshoot using CLI only

Issues resolved

29

Simple Firewall Rules

Add basic rules for port

Traffic allowed

30

Easy Mobile Setup

Use QR code for mobile config

Mobile connects easily

31

Simple QR Code Generation

Generate QR from config

QR scanned successfully

32

Easy Config Backup

Copy config file

Backup works

33

Simple Interface Monitoring

Use wg show

Real-time stats visible

34

Minimal Log Requirements

No verbose logging needed

Logs remain clean

35

Simple Kill Switch Setup

Add kill switch rule

Traffic blocked if VPN drops

36

Easy Config Import

Import config on new device

VPN connects

37

Simple OS Compatibility

Use same config on Linux/macOS/Windows

Works across OS

38

Easy Peer Discovery

Use static IP or DNS

Peer reachable

39

Simple Interface Naming

Use wg0, wg1, etc.

Interface recognized

40

Easy MTU Configuration

Set MTU in config

MTU applied

41

Simple Pre-shared Key Setup

Add PSK in config

Extra encryption enabled

42

No Certificate Management

No need for CA or certs

VPN works without PKI

43

Simple Config Validation

Check config syntax

Errors shown clearly

44

Easy Integration with Systemd

Use systemd service

Interface auto-starts

45

Simple Roaming Support

Change IP without reconnecting

Connection persists

46

Easy Endpoint Update

Peer updates endpoint

New endpoint accepted

47

Simple AllowedIPs Setup

Add AllowedIPs in config

Traffic routed correctly

48

Minimal Resource Usage

Monitor CPU/memory usage

Low usage observed

49

Simple Upgrade Process

Upgrade WireGuard package

No config changes needed

50

Easy Documentation Access

Use man wg or official docs

Clear and concise guidance

High Performance - Testcases

#

Test Case

Description

Expected Result

1

Throughput Benchmark

Measure max data transfer rate

High Mbps/Gbps throughput

2

Latency Measurement

Ping over VPN

Low latency (near native)

3

CPU Usage Test

Monitor CPU during traffic

Low CPU utilization

4

Memory Usage Test

Monitor RAM usage

Minimal memory footprint

5

Multi-Core Utilization

Use multiple cores

Efficient parallel processing

6

Encryption Speed

Measure ChaCha20 performance

Fast encryption/decryption

7

Handshake Speed

Time to complete handshake

Sub-second handshake

8

Reconnection Time

Time to reconnect after drop

Reconnects quickly

9

Packet Processing Rate

Measure packets/sec

High PPS rate

10

Interface Load Test

Simulate heavy traffic

Stable performance

11

Concurrent Connections

Add multiple peers

Handles all peers efficiently

12

High Bandwidth Streaming

Stream HD/4K video

Smooth playback

13

File Transfer Speed

Transfer large files

Fast transfer rate

14

Gaming Performance

Play online games

Low ping, no lag

15

VoIP Quality

Make voice/video calls

Clear audio/video

16

Performance on Mobile

Test on Android/iOS

Efficient battery and bandwidth use

17

Performance on Low-End Device

Use on Raspberry Pi or similar

Acceptable performance

18

Performance on VM

Run in virtual machine

Comparable to host performance

19

Performance on Container

Run in Docker

Efficient operation

20

Performance on Cloud

Deploy on cloud instance

High throughput

21

Performance with IPv6

Use IPv6 traffic

No degradation

22

Performance with IPv4

Use IPv4 traffic

No degradation

23

Performance with NAT

Connect behind NAT

Maintains speed

24

Performance with Roaming

Change IP during session

No noticeable delay

25

Performance with Firewall

Use with strict firewall

No performance drop

26

Performance with VPN Cascade

Chain with another VPN

Acceptable performance

27

Performance with Kill Switch

Enable kill switch

No performance impact

28

Performance with DNS

Use DNS over VPN

Fast resolution

29

Performance with Compression

Use compressed traffic

Improved throughput

30

Performance with UDP Flood

Simulate UDP flood

Handles gracefully

31

Performance with Packet Loss

Introduce packet loss

Maintains connection

32

Performance with Jitter

Introduce jitter

Stable connection

33

Performance with MTU Tuning

Adjust MTU size

Optimized throughput

34

Performance with Large MTU

Use jumbo frames

Improved efficiency

35

Performance with Small MTU

Use small MTU

No fragmentation issues

36

Performance with Pre-shared Key

Add PSK

No performance drop

37

Performance with Logging

Enable verbose logging

Minimal impact

38

Performance with Monitoring

Use monitoring tools

No slowdown

39

Performance with System Load

Run under CPU stress

Maintains VPN speed

40

Performance with Background Apps

Run other apps

No interference

41

Performance with File Sync

Use Dropbox/OneDrive

Fast sync

42

Performance with CDN Access

Access CDN content

Low latency

43

Performance with Cloud Storage

Use Google Drive/S3

Fast uploads/downloads

44

Performance with Remote Desktop

Use RDP/VNC

Smooth experience

45

Performance with SSH

Use SSH over VPN

No lag or delay

46

Performance with Git

Clone/push large repos

Fast operations

47

Performance with Web Browsing

Browse websites

Pages load quickly

48

Performance with Video Calls

Use Zoom/Teams/Meet

No buffering

49

Performance with Speed Test

Run speedtest.net

High download/upload speeds

50

Performance with Multiple Routes

Use multiple AllowedIPs

Efficient routing

Stateless Design - Testcases

#

Test Case

Description

Expected Result

1

Stateless Handshake

Initiate handshake without prior state

Handshake succeeds

2

Stateless Peer Reconnect

Reconnect peer after IP change

Peer reconnects without session tracking

3

Stateless Packet Handling

Send packet without session context

Packet processed correctly

4

No Session Table

Inspect for session tracking

No session table maintained

5

Stateless Key Exchange

Exchange keys without stateful negotiation

Keys exchanged successfully

6

Stateless NAT Traversal

Traverse NAT without connection state

Connection established

7

Stateless Roaming

Change client IP mid-session

Connection persists

8

Stateless Peer Timeout

Wait for peer inactivity

No session timeout mechanism

9

Stateless Packet Replay

Replay old packet

Packet dropped

10

Stateless Packet Loss

Drop packets mid-stream

No session disruption

11

Stateless Peer Restart

Restart peer device

Peer reconnects without issue

12

Stateless Server Restart

Restart server

Clients reconnect automatically

13

Stateless Interface Restart

Restart WireGuard interface

No session recovery needed

14

Stateless Connection Logging

Check logs for session tracking

Only handshake and packet logs

15

Stateless Peer Discovery

No active peer discovery

Peers connect only when sending data

16

Stateless Firewall Traversal

Traverse firewall without session pinning

Connection succeeds

17

Stateless Load Balancing

Switch between servers

No session migration needed

18

Stateless Failover

Failover to backup server

Seamless transition

19

Stateless Packet Inspection

Inspect packet headers

Minimal metadata, no session ID

20

Stateless Protocol Overhead

Measure protocol overhead

Very low overhead

21

Stateless UDP Transport

Use UDP for transport

Stateless by design

22

Stateless Peer Removal

Remove peer from config

No lingering session

23

Stateless Peer Addition

Add peer dynamically

Peer connects immediately

24

Stateless Key Rotation

Rotate keys

No session reset required

25

Stateless Packet Encryption

Encrypt packet without session context

Packet encrypted correctly

26

Stateless Packet Decryption

Decrypt packet without session context

Packet decrypted correctly

27

Stateless Interface Monitoring

Monitor interface for state

No session state observed

28

Stateless Peer Monitoring

Monitor peer activity

Only last handshake timestamp

29

Stateless Connection Recovery

Recover from network drop

Connection resumes without session sync

30

Stateless VPN Kill Switch

Enable kill switch

No session state needed

31

Stateless DNS Resolution

Use DNS over VPN

DNS queries routed statelessly

32

Stateless Peer IP Change

Change peer IP

Connection persists

33

Stateless Peer Endpoint Update

Update endpoint in config

New endpoint used immediately

34

Stateless Interface Shutdown

Shut down interface

No session cleanup required

35

Stateless Interface Boot

Boot interface

Peers connect as needed

36

Stateless Peer Sync

Sync peer config across devices

No session sync needed

37

Stateless Config Reload

Reload config

No session disruption

38

Stateless Peer Rotation

Rotate between multiple peers

No session state retained

39

Stateless Packet Timing

Send packets at irregular intervals

All packets processed

40

Stateless Packet Duplication

Send duplicate packets

Duplicates ignored

41

Stateless Peer Logging

Log peer activity

Only handshake and traffic logs

42

Stateless Interface Logging

Log interface activity

No session logs

43

Stateless Peer Expiry

Remove inactive peer

No session timeout needed

44

Stateless Peer Sync After Reboot

Reboot client

Peer reconnects without session

45

Stateless Server Sync After Reboot

Reboot server

Clients reconnect automatically

46

Stateless Peer Migration

Move peer to new network

Connection persists

47

Stateless Packet Fragmentation

Send fragmented packets

Reassembled without session

48

Stateless Packet Reordering

Send out-of-order packets

Packets processed correctly

49

Stateless Peer Scaling

Add many peers

No session tracking overhead

50

Stateless Protocol Inspection

Analyze protocol behavior

Stateless by design

UDP-Based Transport - Testcases

#

Test Case

Description

Expected Result

1

UDP Port Binding

Bind to default UDP port (51820)

Port bound successfully

2

Custom UDP Port

Use a non-default UDP port

VPN functions normally

3

UDP Packet Transmission

Send encrypted packets over UDP

Packets transmitted successfully

4

UDP Packet Reception

Receive packets on WireGuard interface

Packets received and decrypted

5

UDP NAT Traversal

Connect through NAT

Connection established

6

UDP Hole Punching

Establish peer-to-peer connection behind NAT

Peers connect directly

7

UDP Packet Loss Handling

Drop random packets

Connection remains stable

8

UDP Packet Reordering

Send packets out of order

Packets processed correctly

9

UDP Packet Duplication

Duplicate packets

Duplicates ignored

10

UDP Fragmentation

Send large packets

Packets fragmented and reassembled

11

UDP MTU Tuning

Adjust MTU size

Optimized performance

12

UDP Port Scan Detection

Scan WireGuard port

Port appears closed unless handshake initiated

13

UDP Firewall Traversal

Allow UDP port through firewall

VPN traffic allowed

14

UDP Port Blocking

Block UDP port

VPN fails to connect

15

UDP Port Forwarding

Forward port on router

VPN connects through forwarded port

16

UDP Performance Benchmark

Measure throughput over UDP

High performance observed

17

UDP Latency Test

Measure latency over UDP

Low latency

18

UDP with IPv4

Use IPv4 addresses

Traffic routed correctly

19

UDP with IPv6

Use IPv6 addresses

Traffic routed correctly

20

UDP with Dual Stack

Use both IPv4 and IPv6

Dual stack supported

21

UDP with Mobile Network

Connect over 4G/5G

VPN connects reliably

22

UDP with Wi-Fi

Connect over Wi-Fi

VPN connects reliably

23

UDP with Ethernet

Connect over wired LAN

VPN connects reliably

24

UDP with Satellite

Connect over satellite link

VPN connects with higher latency

25

UDP with VPN-over-VPN

Tunnel WireGuard over another VPN

UDP packets encapsulated

26

UDP with Proxy

Attempt to use HTTP/SOCKS proxy

Fails (UDP not supported by proxy)

27

UDP with IDS/IPS

Monitor UDP traffic with IDS

Encrypted traffic detected but not inspected

28

UDP with QoS

Apply QoS rules to UDP port

Traffic prioritized

29

UDP with Load Balancer

Use UDP-aware load balancer

Traffic distributed correctly

30

UDP with Failover

Switch to backup server on failure

Seamless transition

31

UDP with VPN Gateway

Route traffic through WireGuard gateway

All traffic tunneled

32

UDP with Docker

Run WireGuard in container

UDP traffic flows correctly

33

UDP with VM

Run WireGuard in virtual machine

UDP traffic flows correctly

34

UDP with Cloud Provider

Deploy on AWS/GCP/Azure

UDP traffic allowed with proper rules

35

UDP with Port Knocking

Use port knocking before enabling UDP port

VPN connects after knock

36

UDP with Dynamic IP

Change public IP

VPN reconnects automatically

37

UDP with Static IP

Use static IP

VPN connects reliably

38

UDP with DNS Endpoint

Use domain name instead of IP

DNS resolves and connects

39

UDP with Dynamic DNS

Use DDNS for endpoint

VPN reconnects after IP change

40

UDP with Pre-shared Key

Add PSK to UDP connection

Extra encryption layer added

41

UDP with Packet Inspection

Inspect UDP packets

Encrypted and unreadable

42

UDP with Port Randomization

Use random source port

VPN still connects

43

UDP with Port Restriction

Use restricted port range

VPN adapts and connects

44

UDP with IPv6 NAT

Use NAT66

VPN connects if supported

45

UDP with IPv4 NAT

Use NAT44

VPN connects reliably

46

UDP with Firewall Logging

Log UDP traffic

Logs show encrypted packets

47

UDP with Packet Delay

Introduce artificial delay

VPN remains stable

48

UDP with Packet Jitter

Introduce jitter

VPN remains stable

49

UDP with Packet Corruption

Corrupt UDP packets

Corrupted packets dropped

50

UDP with UDP Flood Attack

Simulate UDP flood

VPN remains stable or throttles

IP Layer Tunneling - Testcases

#

Test Case

Description

Expected Result

1

IP Packet Encapsulation

Send IP packet through tunnel

Packet encapsulated in UDP

2

IPv4 Tunneling

Tunnel IPv4 traffic

IPv4 packets routed securely

3

IPv6 Tunneling

Tunnel IPv6 traffic

IPv6 packets routed securely

4

Dual Stack Tunneling

Use both IPv4 and IPv6

Both types tunneled correctly

5

ICMP Tunneling

Send ping through tunnel

ICMP packets encapsulated

6

TCP Tunneling

Send TCP traffic

TCP packets tunneled securely

7

UDP Tunneling

Send UDP traffic

UDP packets tunneled securely

8

DNS Tunneling

Resolve DNS over tunnel

DNS queries routed securely

9

HTTP Tunneling

Access web pages

HTTP packets tunneled

10

HTTPS Tunneling

Access secure websites

HTTPS packets tunneled

11

IP Fragmentation

Send fragmented IP packets

Fragments reassembled correctly

12

IP Reassembly

Receive fragmented packets

Reassembled successfully

13

IP Header Inspection

Inspect tunneled packet headers

IP headers visible inside UDP payload

14

IP Routing

Route IP packets via WireGuard

Routing works as configured

15

IP Forwarding

Enable IP forwarding

Packets forwarded through tunnel

16

IPsec Comparison

Compare with IPsec

WireGuard uses simpler IP tunneling

17

GRE Comparison

Compare with GRE tunneling

WireGuard uses encrypted UDP instead

18

MPLS Compatibility

Test with MPLS network

IP packets tunneled correctly

19

VLAN Compatibility

Tunnel traffic from VLAN

VLAN traffic encapsulated

20

QoS Tagging

Preserve QoS tags in IP header

Tags retained

21

TTL Preservation

Check TTL value after tunneling

TTL decremented correctly

22

DSCP Preservation

Check DSCP field

DSCP retained

23

IPsec Bypass

Use WireGuard instead of IPsec

Traffic routed via WireGuard

24

Tunnel MTU Test

Test MTU size for IP packets

MTU respected

25

Tunnel Performance

Measure throughput of tunneled IP traffic

High performance observed

26

Tunnel Latency

Measure latency of tunneled IP traffic

Low latency

27

Tunnel Stability

Maintain tunnel during network changes

Tunnel remains stable

28

Tunnel Recovery

Recover tunnel after drop

Tunnel reestablished

29

Tunnel with NAT

Tunnel IP traffic behind NAT

NAT traversal successful

30

Tunnel with Firewall

Tunnel through firewall

Traffic allowed if port open

31

Tunnel with Mobile Network

Tunnel IP traffic over 4G/5G

Tunnel stable

32

Tunnel with Wi-Fi

Tunnel IP traffic over Wi-Fi

Tunnel stable

33

Tunnel with Ethernet

Tunnel IP traffic over LAN

Tunnel stable

34

Tunnel with Satellite

Tunnel IP traffic over satellite

Tunnel works with higher latency

35

Tunnel with VPN Cascade

Tunnel IP traffic through multiple VPNs

Traffic encapsulated multiple times

36

Tunnel with Docker

Tunnel traffic from container

Container traffic routed

37

Tunnel with VM

Tunnel traffic from virtual machine

VM traffic routed

38

Tunnel with Cloud Instance

Tunnel traffic from cloud server

Cloud traffic routed securely

39

Tunnel with IPv6 NAT

Tunnel through NAT66

Tunnel works if supported

40

Tunnel with IPv4 NAT

Tunnel through NAT44

Tunnel works reliably

41

Tunnel with Dynamic IP

Change public IP

Tunnel reconnects automatically

42

Tunnel with Static IP

Use static IP

Tunnel remains stable

43

Tunnel with DNS Endpoint

Use domain name for endpoint

DNS resolves and tunnel connects

44

Tunnel with Dynamic DNS

Use DDNS for endpoint

Tunnel reconnects after IP change

45

Tunnel with Pre-shared Key

Add PSK to tunnel

Extra encryption layer added

46

Tunnel with Packet Delay

Introduce delay

Tunnel remains stable

47

Tunnel with Packet Jitter

Introduce jitter

Tunnel remains stable

48

Tunnel with Packet Corruption

Corrupt IP packets

Corrupted packets dropped

49

Tunnel with Packet Replay

Replay IP packets

Replay protection active

50

Tunnel with IPsec Gateway

Route traffic through IPsec gateway

WireGuard tunnel bypasses IPsec

Key-Based Authentication - Testcases

#

Test Case

Description

Expected Result

1

Key Pair Generation

Generate private and public key

Keys generated successfully

2

Key Format Validation

Check key format (Base64, 32 bytes)

Valid format confirmed

3

Key Length Check

Verify key length

256-bit keys

4

Private Key Protection

Ensure private key is not exposed

Key remains secure

5

Public Key Sharing

Share public key with peer

Peer accepts key

6

Key Pair Matching

Match public key to private key

Keys match

7

Invalid Key Pair

Use mismatched keys

Handshake fails

8

Missing Public Key

Omit public key in config

Peer not authenticated

9

Missing Private Key

Omit private key in config

Interface fails to start

10

Duplicate Public Key

Use same public key for multiple peers

Conflict or overwrite

11

Key Rotation

Replace keys manually

New keys accepted

12

Key Rotation Detection

Detect key change on peer

Handshake re-initiated

13

Key Expiry Simulation

Simulate expired key

Connection fails

14

Key Revocation

Remove peer’s public key

Peer no longer connects

15

Key Reuse Prevention

Use same key across multiple devices

Security warning or conflict

16

Key Logging Protection

Ensure keys are not logged

Logs do not contain keys

17

Key Storage Security

Store keys securely on disk

Keys not world-readable

18

Key in Environment Variable

Load key from environment variable

Interface starts successfully

19

Key in Config File

Load key from config file

Interface starts successfully

20

Key in External File

Reference key from external file

Key loaded correctly

21

Key with Pre-shared Key

Combine public key with PSK

Extra encryption layer added

22

Key with AllowedIPs Restriction

Use key with IP filtering

Only allowed IPs routed

23

Key with Endpoint Change

Change endpoint, keep key

Peer reconnects

24

Key with Roaming

Change IP, keep key

Peer reconnects

25

Key with NAT Traversal

Use key behind NAT

Peer connects successfully

26

Key with Firewall

Use key with UDP port open

Peer connects successfully

27

Key with IPv6

Use key with IPv6 address

Peer connects successfully

28

Key with IPv4

Use key with IPv4 address

Peer connects successfully

29

Key with DNS Endpoint

Use key with domain name endpoint

DNS resolves and connects

30

Key with Dynamic DNS

Use DDNS with key

Peer reconnects after IP change

31

Key with QR Code

Generate QR from config with key

Mobile peer connects

32

Key with Mobile Device

Use key on Android/iOS

Peer connects successfully

33

Key with Cloud Instance

Use key on cloud server

Peer connects successfully

34

Key with Docker Container

Use key in container

Peer connects successfully

35

Key with Virtual Machine

Use key in VM

Peer connects successfully

36

Key with Config Reload

Reload config with new key

New key accepted

37

Key with Interface Restart

Restart interface with same key

Peer reconnects

38

Key with Peer Removal

Remove peer’s key

Peer disconnected

39

Key with Peer Addition

Add new peer with key

Peer connects

40

Key with Logging Enabled

Enable logs

Keys not exposed

41

Key with Monitoring Tools

Use wg show

Keys partially masked

42

Key with Systemd Integration

Load key via systemd unit

Interface starts successfully

43

Key with Config Import

Import config with key

Peer connects

44

Key with Config Export

Export config with key

Peer connects

45

Key with Backup/Restore

Backup and restore config with key

Peer reconnects

46

Key with Multiple Interfaces

Use same key on multiple interfaces

Interfaces operate independently

47

Key with Multiple Peers

Use different keys for each peer

All peers connect

48

Key with Performance Benchmark

Test speed with key-based auth

High performance maintained

49

Key with Stateless Design

Authenticate without session state

Peer connects on demand

50

Key with UDP Transport

Authenticate over UDP

Handshake completes

Roaming Support - Testcases

#

Test Case

Description

Expected Result

1

IP Change During Session

Change client IP mid-session

VPN remains connected

2

Wi-Fi to Mobile Switch

Switch from Wi-Fi to mobile data

VPN reconnects automatically

3

Mobile to Wi-Fi Switch

Switch from mobile data to Wi-Fi

VPN reconnects automatically

4

Roaming Across Networks

Move between different networks

VPN maintains connection

5

Roaming with NAT

Change NAT IP address

VPN adapts and reconnects

6

Roaming with Dynamic IP

Use ISP with dynamic IP

VPN reconnects after IP change

7

Roaming with Static IP

Use static IP

VPN remains stable

8

Roaming with DNS Endpoint

Use domain name for endpoint

DNS resolves new IP

9

Roaming with DDNS

Use dynamic DNS for endpoint

VPN reconnects after IP update

10

Roaming with Mobile Hotspot

Switch to mobile hotspot

VPN reconnects

11

Roaming with Public Wi-Fi

Connect to public Wi-Fi

VPN reconnects securely

12

Roaming with Captive Portal

Connect through captive portal

VPN reconnects after login

13

Roaming with VPN Gateway

Use VPN gateway across networks

Tunnel remains active

14

Roaming with IPv6

Change IPv6 address

VPN adapts

15

Roaming with IPv4

Change IPv4 address

VPN adapts

16

Roaming with Dual Stack

Switch between IPv4 and IPv6

VPN remains connected

17

Roaming with DNS Cache

Use cached DNS entries

VPN reconnects using cached IP

18

Roaming with DNS TTL

Use short TTL for endpoint DNS

DNS resolves new IP quickly

19

Roaming with Firewall

Change to network with strict firewall

VPN reconnects if port allowed

20

Roaming with Port Forwarding

Use port forwarding on new network

VPN reconnects

21

Roaming with UDP Hole Punching

Maintain connection through NAT

VPN reconnects using hole punching

22

Roaming with Pre-shared Key

Use PSK with roaming

VPN reconnects securely

23

Roaming with Peer Update

Peer updates endpoint IP

Connection re-established

24

Roaming with Endpoint Change

Change endpoint manually

VPN reconnects

25

Roaming with Interface Restart

Restart interface after IP change

VPN reconnects

26

Roaming with System Sleep

Sleep and resume system

VPN reconnects

27

Roaming with Airplane Mode

Enable and disable airplane mode

VPN reconnects

28

Roaming with Network Fluctuation

Simulate unstable network

VPN maintains or restores connection

29

Roaming with VPN Cascade

Use WireGuard over another VPN

VPN reconnects through tunnel

30

Roaming with Docker Container

Roam with containerized client

VPN reconnects

31

Roaming with Virtual Machine

Roam with VM client

VPN reconnects

32

Roaming with Cloud Instance

Change IP of cloud instance

VPN reconnects

33

Roaming with Mobile App

Use WireGuard mobile app

VPN reconnects automatically

34

Roaming with Desktop App

Use WireGuard desktop app

VPN reconnects automatically

35

Roaming with Systemd Service

Use systemd to manage interface

VPN auto-restarts on IP change

36

Roaming with Interface Monitoring

Monitor interface for IP change

VPN reconnects on change

37

Roaming with Peer Monitoring

Monitor peer endpoint change

VPN adapts to new endpoint

38

Roaming with DNS Failover

Use multiple DNS records

VPN reconnects using alternate IP

39

Roaming with Multiple Peers

Switch between peers

VPN reconnects to available peer

40

Roaming with Load Balancer

Use DNS load balancing

VPN reconnects to new IP

41

Roaming with IPv6 NAT

Roam through NAT66

VPN reconnects if supported

42

Roaming with IPv4 NAT

Roam through NAT44

VPN reconnects reliably

43

Roaming with Packet Loss

Drop packets during IP change

VPN recovers

44

Roaming with Packet Delay

Delay packets during IP change

VPN recovers

45

Roaming with Packet Reordering

Reorder packets during IP change

VPN handles correctly

46

Roaming with DNSSEC

Use DNSSEC for endpoint resolution

VPN reconnects securely

47

Roaming with VPN Kill Switch

Enable kill switch

Traffic blocked until VPN reconnects

48

Roaming with Logging Enabled

Log roaming events

Logs show IP change and reconnection

49

Roaming with Monitoring Tools

Use wg show to monitor

Endpoint updates visible

50

Roaming with Performance Test

Measure reconnection time

Reconnects within seconds

Cross-Platform Compatibility - Testcases

#

Test Case

Description

Expected Result

1

Linux Compatibility

Install and run on Ubuntu/Debian

VPN connects successfully

2

Windows Compatibility

Install and run on Windows 10/11

VPN connects successfully

3

macOS Compatibility

Install and run on macOS

VPN connects successfully

4

Android Compatibility

Use WireGuard app on Android

VPN connects successfully

5

iOS Compatibility

Use WireGuard app on iOS

VPN connects successfully

6

FreeBSD Compatibility

Install and run on FreeBSD

VPN connects successfully

7

OpenBSD Compatibility

Install and run on OpenBSD

VPN connects successfully

8

Raspberry Pi Compatibility

Run on Raspberry Pi OS

VPN connects successfully

9

Docker Container Support

Run inside Docker container

VPN connects successfully

10

Virtual Machine Support

Run inside VM (e.g., VirtualBox, VMware)

VPN connects successfully

11

Cloud VM Support

Run on AWS/GCP/Azure instance

VPN connects successfully

12

Cross-Platform Key Sharing

Use same key on different OS

Keys accepted and VPN connects

13

Config File Portability

Use same config across OS

Config works without modification

14

CLI Support on Linux

Use wg and wg-quick commands

Commands execute correctly

15

GUI Support on Windows

Use WireGuard GUI

Interface starts and connects

16

GUI Support on macOS

Use WireGuard GUI

Interface starts and connects

17

Mobile App UI Consistency

Compare Android and iOS apps

Similar UI and functionality

18

Systemd Integration on Linux

Use systemd to manage interface

Interface auto-starts

19

Launch Agent on macOS

Use launchd for auto-start

Interface auto-starts

20

Windows Service Integration

Use Windows service for auto-start

Interface auto-starts

21

IPv4 Support on All Platforms

Route IPv4 traffic

IPv4 works on all OS

22

IPv6 Support on All Platforms

Route IPv6 traffic

IPv6 works on all OS

23

DNS Resolution on All Platforms

Use DNS over VPN

DNS queries resolved securely

24

MTU Configuration on All Platforms

Set MTU in config

MTU applied correctly

25

Interface Naming Consistency

Use wg0, wg1, etc.

Interface recognized across OS

26

Log File Access

Access logs on each OS

Logs available and readable

27

Performance Benchmark on Linux

Measure throughput

High performance observed

28

Performance Benchmark on Windows

Measure throughput

High performance observed

29

Performance Benchmark on macOS

Measure throughput

High performance observed

30

Performance Benchmark on Android

Measure throughput

Acceptable performance

31

Performance Benchmark on iOS

Measure throughput

Acceptable performance

32

Config Import on Mobile

Import config via QR code

VPN connects successfully

33

Config Export from Desktop

Export config to mobile

Config works on mobile

34

Roaming Support on Mobile

Switch networks on mobile

VPN reconnects automatically

35

Roaming Support on Desktop

Switch networks on laptop

VPN reconnects automatically

36

Firewall Compatibility on All OS

Use with OS-specific firewall

VPN traffic allowed

37

NAT Traversal on All OS

Connect behind NAT

VPN connects successfully

38

Kill Switch on Linux

Block traffic if VPN drops

Traffic blocked

39

Kill Switch on Windows

Block traffic if VPN drops

Traffic blocked

40

Kill Switch on macOS

Block traffic if VPN drops

Traffic blocked

41

IPv6 Leak Protection

Prevent IPv6 leaks

No leaks detected

42

DNS Leak Protection

Prevent DNS leaks

No leaks detected

43

Update Compatibility

Upgrade WireGuard version

Configs remain compatible

44

Multi-User Support on Windows

Use with multiple user accounts

VPN works per user

45

Multi-User Support on Linux

Use with multiple user accounts

VPN works per user

46

Multi-User Support on macOS

Use with multiple user accounts

VPN works per user

47

Battery Usage on Mobile

Monitor battery impact

Efficient usage observed

48

Background Operation on Mobile

Run VPN in background

VPN remains active

49

App Store Availability

Available on Google Play and App Store

Easy installation

50

Open Source Availability

Source code available for all platforms

Builds and runs successfully

Easy Configuration - Testcases

#

Test Case

Description

Expected Result

1

Minimal Config File

Use only required fields

VPN connects successfully

2

Config File Syntax Validation

Check for syntax errors

Errors clearly reported

3

Config File with Comments

Add comments to config

Comments ignored, config works

4

Config File with Extra Spaces

Add whitespace in config

Config still valid

5

Config File with Tabs

Use tabs instead of spaces

Config still valid

6

Config File with Inline Comments

Add inline comments

Config still valid

7

Config File with Multiple Peers

Add multiple peers

All peers recognized

8

Config File with DNS Entry

Add DNS entry

DNS queries routed through VPN

9

Config File with MTU

Set MTU value

MTU applied correctly

10

Config File with Table Format

Use INI-style format

Parsed correctly

11

Config File with IPv6

Add IPv6 address

IPv6 traffic routed

12

Config File with IPv4

Add IPv4 address

IPv4 traffic routed

13

Config File with Endpoint Hostname

Use domain name instead of IP

DNS resolves and connects

14

Config File with Port Number

Specify custom port

Port used correctly

15

Config File with AllowedIPs

Define AllowedIPs

Traffic routed as specified

16

Config File with PersistentKeepalive

Enable keepalive

Keepalive packets sent

17

Config File with Pre-shared Key

Add PSK

Extra encryption layer added

18

Config File with Multiple Interfaces

Define multiple interfaces

All interfaces start correctly

19

Config File with External Includes

Reference external files

Config loads successfully

20

Config File with QR Code

Generate QR from config

Mobile device connects

21

Config File with Environment Vars

Use env vars for keys

Keys loaded correctly

22

Config File with Systemd

Use with systemd unit

Interface auto-starts

23

Config File with Launchd (macOS)

Use with launchd

Interface auto-starts

24

Config File with Windows Service

Use with Windows service

Interface auto-starts

25

Config File with Comments Only

Use config with only comments

Interface does not start

26

Config File with Invalid IP

Use malformed IP address

Error reported

27

Config File with Invalid Port

Use invalid port number

Error reported

28

Config File with Invalid Key

Use malformed key

Error reported

29

Config File with Duplicate Keys

Use same key for multiple peers

Warning or error shown

30

Config File with Missing Fields

Omit required fields

Interface fails to start

31

Config File with Extra Fields

Add unsupported fields

Ignored or error shown

32

Config File with Inline Key

Embed key directly

Key accepted

33

Config File with External Key File

Reference key from file

Key loaded successfully

34

Config File with Backup/Restore

Backup and restore config

VPN reconnects

35

Config File with GUI Import

Import config via GUI

Interface starts

36

Config File with CLI Import

Import config via CLI

Interface starts

37

Config File with Mobile Export

Export config to mobile

Mobile connects successfully

38

Config File with Peer Removal

Remove peer from config

Peer disconnected

39

Config File with Peer Addition

Add peer to config

Peer connects

40

Config File with Interface Restart

Restart interface with same config

Interface reconnects

41

Config File with Interface Rename

Rename interface in config

Interface recognized

42

Config File with IPv6 Only

Use only IPv6

VPN connects

43

Config File with IPv4 Only

Use only IPv4

VPN connects

44

Config File with DNS Only

Use DNS without IP

DNS resolves and connects

45

Config File with Static IP

Use static IP

VPN connects

46

Config File with Dynamic IP

Use dynamic IP

VPN reconnects after change

47

Config File with Roaming Enabled

Enable roaming

VPN reconnects on IP change

48

Config File with Logging Enabled

Enable logging

Logs show connection details

49

Config File with Compression

Add compression (if supported externally)

Traffic compressed

50

Config File with Comments in Peer

Add comments in [Peer] section

Config still valid

  • Reference links