LEAP

What is Expansion of LEAP?

LEAP stands for Lightweight Extensible Authentication Protocol.

What is LEAP?

LEAP is a proprietary EAP authentication method developed by Cisco that uses a modified version of MS-CHAP for mutual authentication between client and server. It was designed for wireless network access.

Why is LEAP useful?

  • Provided early wireless authentication support.

  • Simple to deploy with Cisco infrastructure.

  • Offered mutual authentication between client and server.

  • Enabled dynamic WEP key generation.

How it works?

  • User provides username and password.

  • Server challenges client with a random value.

  • Client hashes password with the challenge and sends response.

  • Server verifies response and sends its own response.

  • Both sides mutually authenticate and derive session keys.

Where is LEAP used?

  • Originally used in Cisco-based enterprise Wi-Fi networks.

  • Mostly deprecated today due to security weaknesses.

Which OSI layer does this protocol belong to?

  • Application Layer (Layer 7).

  • Operates over the EAP framework transported via lower layers like EAPOL.

Is LEAP Windows specific?

  • Not Windows-specific, but was supported via Cisco software on multiple platforms.

Is LEAP Linux specific?

  • No, but not widely supported on modern Linux systems due to security concerns and proprietary nature.

Which Transport Protocol is used by LEAP?

  • EAP is carried over: * EAPOL (Ethernet) * RADIUS (UDP)

Which Port is used by LEAP?

  • RADIUS: UDP port 1812

Is LEAP using Client server model?

  • Yes, LEAP uses a client-server model: * Supplicant (client) * Authentication Server (e.g., RADIUS)

Whether LEAP protocol uses certificates?

  • No, LEAP does not use certificates.

  • It relies on password-based mutual authentication.

How many frame exchanges are seen during connection for LEAP protocol?

  • Typically 6–8 EAP message exchanges including challenge and response messages.

Whether LEAP Protocol uses client certificates?

  • No, client certificates are not used.

Whether LEAP Protocol uses Server Certificates?

  • No, server certificates are not used either.

Does LEAP Protocol depend on TCP?

  • No, LEAP does not directly use TCP.

Does LEAP Protocol depend on UDP?

  • Yes, when RADIUS is used for authentication backend, it uses UDP.

What are the roles involved when testing LEAP Protocol?

  • Supplicant (client)

  • Authenticator (e.g., AP)

  • Authentication Server (RADIUS)

  • Directory service (e.g., Active Directory)

Does LEAP Protocol work with FreeRADIUS server on Linux?

  • Not natively supported due to being proprietary.

  • Some workarounds may exist but it’s not recommended or secure.

Does LEAP Protocol work with internal RADIUS server of hostapd?

  • No, hostapd does not support Cisco LEAP.

What is the RFC version used for LEAP Protocol?

  • LEAP is not standardized in any RFC.

  • It is a Cisco proprietary protocol.

During Connection Procedure which EAPOL Packets are encrypted?

  • EAPOL packets are not encrypted by default.

  • LEAP relies on mutual authentication and dynamic WEP key generation after auth.

Can you Explain different stages of Connection Procedure for LEAP Protocol?

  • Client sends EAP Identity.

  • Server sends challenge.

  • Client responds with password-based hash.

  • Server verifies and responds with own hash.

  • If successful, session is established and keys are derived.

What is the final output of Connection Procedure?

  • Dynamic WEP session key used for securing wireless data.

What is the format of the key generated after the connection procedure?

  • Varies, typically WEP keys of 64 or 128 bits depending on configuration.

Topics in this section,

  • In this section, you are going to learn

  • Terminology

  • Version Info

  • rfc details

  • setup

  • setup

  • setup

  • packet details

  • usecases

  • features

  • Reference links