Cisco has a few proprietary protocols, though many of them have been standardized, or adapted into emerging standards. The most popular Cisco proprietary protocol that hasn't been adopted as a standard is probably EIGRP. bit.ly/1OMvbZW
The ISL protocol can be used in Cisco routers when configuring the subinterfaces.
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.
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.
Yes
CDP is a Cisco proprietary protocol; it only works between Cisco devices. If CDP is enabled on a Cisco network device, it will regularly send frames with information about itself out its interfaces.CDP is a Cisco proprietary protocol; it only works between Cisco devices. If CDP is enabled on a Cisco network device, it will regularly send frames with information about itself out its interfaces.CDP is a Cisco proprietary protocol; it only works between Cisco devices. If CDP is enabled on a Cisco network device, it will regularly send frames with information about itself out its interfaces.CDP is a Cisco proprietary protocol; it only works between Cisco devices. If CDP is enabled on a Cisco network device, it will regularly send frames with information about itself out its interfaces.
HDLC
Layer 2 Tunneling Protocol (L2TP)
HDLC
This is a command line use in Cisco devices to show neighbors which is using Cisco Discovery Protocol (CDP).