PPTP tunneling was developed by Microsoft.
Layer 2 Tunneling Protocol (L2TP)
ISL IS A CISCO PROPRIETARY TUNNELING PROTOCOL, BUT 802.1 q IS A OPEN STANDARD PROTOCOL
Tunneling in Cisco refers to the process of encapsulating one type of network protocol within another protocol to facilitate secure communication over a public or untrusted network. This technique is commonly used in Virtual Private Networks (VPNs) to create a secure "tunnel" for data packets, ensuring confidentiality and integrity. Cisco devices support various tunneling protocols, such as GRE (Generic Routing Encapsulation) and IPsec, which allow for the transport of data between remote sites or users and the corporate network. Tunneling enhances security by encrypting data and masking the original source and destination addresses.
LEAP Lightweight Extensible Authentication Protocol, developed by Cisco, it allows for rotating WEP keys for wireless encryption, it's based on MS-CHAP authentication by Microsoft. This is outdated and should not be used unless necessary. PEAP is a joint venture between Microsoft, Cisco, and RSA for secure TLS tunneling with PKI certificates as authentication. EAP FAST is the new version of LEAP
LEAP Lightweight Extensible Authentication Protocol, developed by Cisco, it allows for rotating WEP keys for wireless encryption, it's based on MS-CHAP authentication by Microsoft. This is outdated and should not be used unless necessary. PEAP is a joint venture between Microsoft, Cisco, and RSA for secure TLS tunneling with PKI certificates as authentication. EAP FAST is the new version of LEAP
Cisco Technical Documentation
Enhanced Interior Gateway Routing Protocol (EIGRP) was once as Cisco Propitiatory routing protocol for Cisco routers. However many routers that are not Cisco now support the use of EIGRP.
The ISL protocol can be used in Cisco routers when configuring the subinterfaces.
EIGRP
CDP
this is a cisco propreitory protocol is not available for rfc
IGRP is Interior Gateway Routing Protocol, enhanced by Cisco proprietary Enhanced IGRP.