Muhammad Khattak
Routing and switching specialist, CCNA certified, with extensive experience in network configuration and troubleshooting. Covers OSPF, EIGRP, VLAN management, and advanced routing concepts.
Frame Relay Address Mapping Exclusive
Cisco routers support all network layer protocols such as IPv4, IPv6, IPX, and AppleTalk over Frame Relay. For transmitting data over Frame Relay, it needs to know which local DLCI maps to the Layer 3 address of the remote destination. In simple words Frame Relay address mapping matches a next-hop IP address that sits on...
How to Configure Challenge Handshake Authentication Protocol (CHAP)
Challenge Handshake Authentication Protocol is the standard PPP authentication method for securing point-to-point WAN links on Cisco routers. It authenticates the remote router without transmitting the password in plain text, protecting the link against replay attacks through a randomly generated challenge value that changes with each authentication attempt. This guide covers how it works, its...
PPP Configuration
Remember that HDLC is the default encapsulation protocol for Cisco routers. If PPP configuration is not done on Cisco routers, the default encapsulation will be used. To set PPP as the encapsulation method used by a serial interface we need PPP configuration on the serial interfaces. The PPP configuration for the below topology is following....
LCP Options
PPP support different option than can be configured optionally. Authentication using PAP or CHAP, Compression using either Stacker or Predictor and Multilink that combines two or more channels to increase the WAN bandwidth. To negotiate these PPP options, the LCP link-establishment frames contain option information in the data field of the LCP frame, as shown...
PPP Session: LCP Phases, Packet Structure, and Frame Types
When two devices are first turned on, there is no active link-layer connection between them. Once the physical connection is made, the devices can begin establishing a PPP (Point-to-Point Protocol) session. There are three phases to establishing a PPP session: Phase 1: Link establishment and configuration negotiation Before PPP exchanges any network layer datagrams, such...
Point-to-Point Protocol (PPP) Components – Exclusive Defination
A layered architecture is a logical model that aids communication between interconnecting layers. We can map the Point-to-Point Protocol (PPP) layer model with the Open System Interconnection (OSI) model. Both Point-to-Point Protocol (PPP) and OSI models share the same physical layer although the Point-to-Point Protocol (PPP) distributes the functions of Link Control Protocol (LCP) and...
HDLC Encapsulation Protocol
HDLC is the default encapsulation protocol on point-to-point connections, dedicated links, and circuit-switched links when both ends of the link are Cisco devices. It is a synchronous Data Link layer bit-oriented protocol, originally developed from IBM’s Synchronous Data Link Control (SDLC), and later standardized by ISO as ISO/IEC 13239. HDLC provides both connection-oriented and connectionless...
WAN Encapsulation Protocols
The network layer passes the data to the data link layer for transmission over the physical layer. The Data Link layer creates frames by adding the necessary checks and controls around the Network layer data. The encapsulation on a router serial interface must be configured to guarantee the correct encapsulation method is used. Different WAN...
Statistical Time-Division Multiplexing (STDM): Complete Guide
Statistical Time-Division Multiplexing is an advanced multiplexing technique that dynamically allocates transmission time slots to active channels, eliminating the bandwidth waste inherent in standard Time-Division Multiplexing (TDM). Understanding STDM — how it differs from TDM and FDM, how its frame structure works, and where it is applied in real WAN protocols — is essential knowledge...
Basic EIGRP Troubleshooting Commands – Exclusive Introduction
Due to the importance of EIGRP troubleshooting problems related to this protocol is an important ability for a network administrator. There are numerous commands that are important during EIGRP troubleshooting. The most used command for EIGRP troubleshooting is the “show ip eigrp neighbors”, “show ip route”, and “show ip protocols”. The commands can also be...