Cisco

44 flashcards · Other · by Emanuel Gostner

1. Physical topology

   Physical location of Devices and media

2. Logical topology

   Identify ports/Interfaces and Subnetting

3. Network types (LAN, WAN...)

   LAN (local area network): Network within a company MAN (Metropolitan area network): Connected networks within city WAN (wide area network): Connected networks accros various countries SAN (Storage area network): Network specialized for storing server

4. Difference Internet/internet

   Internet: connection on a global scale internet: multiple networks are connected

5. Intranet/Extranet

6. Connection types to Internet

   Cable: same cable that is used for television service DSL (Digital Subscriber Lines): runs over telephone line. ADSL (Asymmetrical DSL): download fast than upload SDSL (Symmetrical DSL): same as ADSL but with same download/upload Cellular: the phone network is used, speed dependent on cell tower and phone Satellite: beneficial in remote areas. satellite dishes must have clear sight to the satellites Dial-up telephone: low bandwidth. Connects to ISP trough telephone wires. Like 56k. While phonin…

7. Converging networks and dedicated networks

   Converging networks: Over the same network telephone, video and data can be send to lots of different devices. Multiple Services are carried over the same network. Dedicated Network: Network is specialized to offer one service

8. Confidentiality (security)

   Only the authorized person can access the data (security)

9. Integrity (security)

   Data is not altered or changed without the user permission (security)

10. Availability (security)

    Data is available when the user needs it

11. Powerline networking

    existent wiring is used to transmit data on a own frequency (homes, IoT devices). Alternative to networking cables and wireless

12. WISP

    Wireless Internet Service Provider: Connection from home to ISP is wireless instead of cables. Transmission towers are installed on elevated buildings/towers

13. kernel

    part of the OS taht interacts directly with the computer hardware hardware <-> Software

14. shell

    Interface between user and OS. CLI (command-line) or GUI can be used

15. OS on cisco devices? How is the OS mostly called on routers?

    IOS for cisco routers or firmware for routers in general

16. Rollover cable

    used to connect a pc to a Console port on router/switch

17. What is physicall necessary to connect to a network

    NIC (Network interface card) or WLAN NIC

18. Frame encoding

    L1 physical layer encodes frames into bits and sends them via: electrical optical radio signals

19. copper cable

    Twisting: protects signals from interferences and crosstalk STP: offers more protection against interferences Coaxial: mostly replaced by STP. Used to transmit RFI(Radio Frequency signals) UTP: Straight-trough: host to switch, switch to router Crossover: connect similar devices ex. switch to switch Rollover: Connect Workstation to a router/switch console port

20. fibre-optic cable

    immune to Radio Frequence interference (RFI) and Electromagnetic interference (EMI)

21. fibre optic MM

    Multi-mode: Es wird ein Diffuses Licht durch den Lichtwellenleiter gestrahlt geringere Reichweite, da die einzelnen Lichtwellen unterschiedlich ankommen (3KM)

22. Wireless disadvantages

    only available in half-duplex susceptible to interference (household devices) easier to hack (no physical connection needed)

23. fibre optic SM

    Single-mode: Es wird ein gebündelter Laserstrahl durch den Lichtwellenleiter gestrahlt höhere kosten höhere Reichweite (70km)

25. WAN topologies

26. Switching Methods

    store-and-forward: Frame is stored in a buffer until the whole frame is received. Meanwhile dest. mac/error check Cut-Through: Fragment-free switching: Only first 64 bytes are error checked (most prone for errors) Fast-forward switching: directly forwarded, only dest. address buffered

27. Memory Buffering

    Frames are stored in memory before they are sent

28. Memory Buffering methods

    port-based: Frames are stored according to their destination. Each port needs it's own memory. Frames are buffered in queues linked to specific ports. shared memory buffering: All ports share the same memory

29. Switch setting that detects aut. which cable type it needs

    Auto-MDIX: Wether a cross-over/straight-trough is needed

30. Ethernet frame size: how are they called if to big/small?

    64-1518 bytes. Preamble excluded > Jumbo/Baby giant frame < runt frame/colission frame

31. MAC table behavior Ipv4 dest. address in local/remote network

    Falls die Dest. IPv4 Adresse im eigenen Netz ist, wird die MAC des jeweiligen End-Gerätes in den Header gesetzt. Falls die Dest. IPv4 Adresse nicht im eignen Netz ist, wird die MAC des Routers (default gateway) in den Header gesetzt.

32. IP characteristics. Which layer?

    Layer 3 Connectionless: no connection establishment before sendind packets Best Effort: not reliable (lost packets are handled by upper layers)

33. IPv4 Header

    Version: ipv4 DS (Differentiated Services): priority (QoS) Time to life: value-- each time packet processed by router Protocol: defines next upper protocol (TCP/UDP/ICMP)

34. NAT?

    Network Address Translation: public Ipv4 are shared by multiple devices

35. Ipv6 Header

    Version: IPv6 Traffic class: like IPv4 DS-> priority Flow label: packets with same flow label receive same type of handling by Router Next Header: same as IPv4 "Protocol" Hop Limit: time to live

36. Router Bootup Process

    ROM: load bootstrap Flash: load operating system NVRAM: load config file

37. IPv6 Apipa equivalent

    Stateless Address Autoconfiguration (SLAAC): equivalent to Apipa. Uses ICMPv6 to assign IPs

38. Ipv6 DHCP Equivalent

    DHCPv6

39. IPv6 Router Advertisment options (RA)

40. IPv6 ARP equivalent

    NS-Messages

41. stateless/statefull difference

    stateful: with server stateless: without server

42. traceroute functionality

    Traceroute: progressively increases the TTL (Time to live) or HOP count (IPv6) to get every node. 1 TTL -> gets response from first Router 2 TTL -> gets response from second Router … this way traceroute gets information of every router the packet has to pass to it's destination

43. Ping functionality

    Ping uses ICMP echo request: test connectivity to another host ICMP: provides feedback of IP packet transmission

44. broadcast types:

    directed broadcast: broadcast to certain remote network limited broadcast: limited to local network multicast: hosts that are subscribed to a multicast group