Welcome! CISCO CERTIFIED NETWORK ASSOCIATE

WELCOME! Goal – Cisco Certified Network Associate, Cisco Certified Network Professional, and beyond! About Me Overall view of classes Switching Basics (frames, broadcast / collision domains, arp) Switching advanced (stp, portfast, root bridge, vtp pruning, trunking, port-channels) Routing Basics (static, rip, ospf, eigrp) Routing advanced (route redistribution, changing metrics) Other awesome topics NAT, IPv6, Binary / Hex conversion, subnet maths, summarization PPP and Frame Relay First interview question Next…Topics to cover today

TOPICS TO COVER Hardware (Where (decent places), what (3550, 3560, or 2950), why (emulation?) Cables / cabling needs (Auto MDIX – medium dependent interface crossover) Boot (ROMMON, flash, ROM, RAM, NVRAM, running-config, startup-config), diagnostics Switching Basics Models (TCP/IP, versus DoD) Frames (hubs, repeaters, flooding, broadcast / collision domains) – examples VLANing Mac addressing (OUI vey) Arp CDP VTP Next…Hardware

HARDWARE Where (decent places) What to buy (3550, 3560, or 2950) CCNA – , or 3550, 2900 series (RAM!) CCNP – Add 2 more 3550 and two more 2900 routers TSHOOT Exam Topology Why (emulation?) GNS3 – Wireshark ( Cables / cabling needs (Auto MDIX – medium dependent interface crossover) both have Auto MDIX otherwise crossover cables it is Next…Boot

BOOT 1. Bootstrap program ROMmon runs Power On Self Test (POST) 2. Bootstrap checks the Configuration Register in startup config file If nothing is there it will load from Flash No flash it will try to load from a TFTP server (assuming that you have one set up on the network / program one in, ASA) If no TFTP server you would have to manually enter TFTP info from ROMMON (SERVER =, SUBNET MASK=, etc.) 3. IOS found now it is loaded into RAM (Self-decompressing the image: ####...) 4. Config file loaded from NVRAM (dir) into RAM if none found Setup dialogue Next…Switching

SWITCHING BASICS Models (Layers, TCP/IP versus DoD, real world) Vlanning (Broadcast, Collision domains)

MODELS TCP / IP (A Pizza Sure Tastes Nice During Presentations) Application – HTTP, everything Presentation – Human to computer (Layer 6) Session – Build and tear down of session (Layer 5) Transport – TCP/UDP (Layer 4) – a.ka. segment Network – IP Address (Layer 3) – a.k.a. packet Data Link – MAC (Layer 2) – a.k.a. frame Physical (Layer 1) DoD Application (5 and up) Host-To-Host Layer (4) Internet Layer (3) Network Interface Layer (1 and 2) Next…Vlanning

VLANING Broadcast Domains – Stops at a Router (L3 device edge) Collision Domains (hubs, repeaters) – Collision, hardware needs to listen for silence Switches eliminate this by moving the collision domain to the specific port Next…MAC Addresses

MAC ADDRESSES Mac address – unique identifier on a broadcast domain Entire thing 6 bytes (48 bits) OUI (first 3 bytes – or 24 bits) If someone says, “For ease of use I need to duplicate my mac, can I?” What do you ask them? Next…Address Resolution Protocol

ADDRESS RESOLUTION PROTOCOL Arp requests – Hey who has an ip address of ? Send a broadcast out ff:ff:ff:ff:ff:ff No MAC supplied in the arp request Arp replies – Hey I have it! GNS3 example Loop traffic? ( - self looped porthttps://supportforums.cisco.com/message/ # do wr, copy runnning-config startup-config, wr mem Next…Cisco Discovery Protocol

CISCO DISCOVERY PROTOCOL Cisco device sends out a multi-cast to 01:00:0c:cc:cc:cc with its mac address as source No two way communication just multicasts

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