BZUPAGES.COM Introduction to Cisco Devices Interfaces and modules –LAN interfaces (Fast Ethernet, Gigabit Ethernet) –WAN interfaces(Basic Rate Interface (BRI),Synchronous & Asynchronous Serial, T1 Controller Card) Data Communications Equipment (DCE) –Modem –Channel Service Unit/Data Service Unit (CSU/DSU) Data Terminal Equipment (DTE) –Router – PC –Server Demarcation point CPE

BZUPAGES.COM Cisco Memory Components ROM Flash RAM NVRAM

BZUPAGES.COM Cisco Router Models and Features 800 Series—Fixed-port and fixed-configuration routers that support Asymmetric Digital Subscriber Line (ADSL), ADSL over ISDN, Single-pair High-Speed DSL(G.SHDSL), Serial, and ethernet to an external cable modem or DSL connections Series—Modular multiservice access routers that support built-in Fast Ethernet LAN ports and WAN/voice modular slots. They can support branch offices Series—Can be used with an Enterprise Edge or Service Provider Edge environment. They can support Fast Ethernet, Gigabit Ethernet, and Packet. Chassis slots are open for installation of more than 70 network interfaces.

BZUPAGES.COM Cisco Switch Models and Features 2950 Series—Includes a fixed-configuration switch that can support both Fast Ethernet and Gigabit Ethernet connections. Monitoring network and system state Series—Are stackable switches that can employ Cisco Switch Clustering technology, and support Layer 3 functionality Series—Can support high-density copper, fiber-based interfaces, Fast Ethernet,Gigabit Ethernet connections, and Layer 3 functionality Series—Can support Power over Ethernet (PoE) devices, 10/100Mbps ethernet ports, 10/100/1000Mbps ethernet ports, 10Gbps ethernet ports, and Layer 3 functionality. Self-identification of system components. Separate testability of components.

BZUPAGES.COM Switching Functionality PDU(Protocol data unit) 4 (transport) TCP segment TCP port 3 (network) Packet Router 2 (data link) Frame Switch/bridge Layer 2 Switching ■ MAC addresses are learned from the incoming frames’ source addresses. ■ A table of MAC addresses and their associated bridge and switch ports is built and maintained. ■ Broadcast and multicast frames are flooded out to all ports (except the one that received the frame). ■ Frames destined for unknown locations are flooded out to all ports (except the one that received the frame). ■ Bridges and switches communicate with each other using the Spanning Tree Protocol to eliminate bridging loops.

BZUPAGES.COM Switching Functionality Layer 3 Switching ■ Packets are forwarded at Layer 3, just as a router would do. ■ Packets are switched using specialized hardware, application-specific integrated circuits (ASIC), for high speed and low latency. ■ Packets can be forwarded with security control and quality of service (QoS) using Layer 3 address information. Layer 4 Switching ■ Packets are forwarded using hardware switching, based on both Layer 3 addressing and Layer 4 application information. (Layer 2 addressing is also inherently used.) ■ Layer 4 protocol types (UDP or TCP, for example) in packet headers are examined. ■ Layer 4 segment headers are examined to determine application port numbers.

BZUPAGES.COM Switching Functionality Multilayer Switching ■ Packets are forwarded in hardware that combines Layer 2, Layer 3, and Layer 4 switching. ■ Packets are forwarded at wire speed. ■ The traditional Layer 3 routing function is provided using Cisco Express Forwarding (CEF), in which a database of routes to every destination network is maintained and distributed to switching ASICs for very high forwarding performance.

BZUPAGES.COM VLAN & Trunking VLAN Frame Identification Frame Identification or Tagging A Unique Identifier as VLAN ID Only Used for Trunk Links Two Methods are Used Inter-Switch Link (ISL) protocol IEEE 802.1Q protocol Both ends must have the same method

BZUPAGES.COM VLAN & Trunking Inter-Switch Link Protocol Cisco-proprietary method Layer 2 encapsulating 26-byte header & a 4-byte trailer 15-bit VLAN ID & CRC in trailor double tagging

BZUPAGES.COM VLAN & Trunking IEEE 802.1Q Protocol Standardized method Support multiple vendor internal tagging. concept of a native VLAN 4-byte tag just after the source address field 2- bytes for Tag Protocol Identifier (TPID) 2-bytes for Tag Control Information (TCI)

BZUPAGES.COM Virtual LAN Trunking prtocol VTP Modes Server mode Client mode Transparent mode

BZUPAGES.COM VTP Advertisement

BZUPAGES.COM VTP Advertisement

BZUPAGES.COM VTP Advertisement

BZUPAGES.COM Spanning Tree Potocol

BZUPAGES.COM Spanning Tree Protocol Bridging Loops Bridge Protocol Data Units –STP multicast address c –Configuration BPDU, used for spanning-tree computation –Topology Change Notification (TCN) BPDU, used to announce changes in the network topology Electing a Root Bridge –Bridge Priority (2 bytes)( ) –Default is 32,768. –MAC Address (6 bytes) –Lower is better

BZUPAGES.COM Spanning Tree Protocol

BZUPAGES.COM Spanning Tree Protocol

BZUPAGES.COM Spanning Tree Protocol STP states –Disabled –Blocking –Listening –Learning –Forwarding STP Timers –Hello (2 s) –Forward delay( 15 s) –Max age(20 s)

BZUPAGES.COM Spanning Tree Protocol

BZUPAGES.COM Routing Functionality Layer 3 Routing –application-specific integrated circuits (ASIC) ■ Packets are forwarded between networks based on Layer 3 addresses. ■ An optimal path is determined for a packet to take through a network to the next router. ■ Packet forwarding involves a table lookup of the destination network, the next-hop router address, and the router’s own outbound interface. ■ An optimal path can be chosen from among many possibilities. ■ Routers communicate with each other using routing protocols. ■ No broadcast, Only multicast