CCNA 200-125 Tips 2: Points to Remember

1. To to see how many management packets have been sent to the frame relay switch?
    - show frame relay lmi

2. To find out if your static NAT is working or not?
     - show ip nat translations.

3. Which command will generate a level 7 password in router?
    - enable password

4. If you want to ping router R2 continuously on your network with IP

    address 172.16.3.1. Which command will you use to ping a name.
    - R1(config)# ip host R2 172.16.3.1

5. You need to leave the room for few minutes and want to secure the console

    session on your laptop with one time password . Which two commands will

    u need to apply?
    - lock and lockable

6. You are configuring an EIGRP hub router and you need it to advertise a network

    out of the same interface it learned it on . What command will accomplish it ?
    - R (config-if)# no ip split-horizon eigrp 100

7. Which command will enable a secure version of CHAP to be sent from your router

    to a neighbor router?
    - R1(config-if)# ppp authentication chap

8. You want your router interface to forward DHCP requests to a specific router on

    the network. What command will achieve this?
    -R(config-if)# ip helper-address 10.1.1.1

9. opsf hello interval can be changed and it should be in sec
    Router(config-if)#ip ospf hello-interval ?
    <1-65535>  Seconds

10. ­­Dead interval will change automatically once there is change in hello

11. We need to change hello interval on both routers which are going to form

      neighbor otherwise adjacency won't happen.

12. On point to point network we need to configure frame-relay interface-dlci 321

      instead of frame-relay map command. Frame-relay map command is used in

      point to multipoint n/w

13. For hub and spoke topology we need to configure neighbor in hub and set

      the priority to 0 in spokes to restrict them to take part in ospf DR/BDR process.

14. attempt will only seen in NBMA

15. Timer default for point to point are 10 sec and 40 sec but for etherent and

      non broadcast NBMA hello is 30 and dead is 120 secs.

16. The channel provided by ISDN BRI is
      -2B+ 1D

17. Running both Ipv4 and ipv6 on a router simultaneously is known as

      dual-stack tunneling.

18. Three Ipv6 transition mechanism?
      -6t04 tunneling
      -ISATAP tunneling
      -teredo tunneling

19. antispyware: detects software designed to capture sensitive information                                                                   

     and removes it from the computer

20. firewall: filters traffic based on source and destination IP address or traffic type

21. Five steps of boot sequence
     The power-on self test executes
     The bootstrap loader in ROM executes
     The IOS is loaded based on boot system command in NVRAM
     The router looks for the configuration in NVRAM
     If no configuration file is located, the setup dialog initiates.

22. Rollover: PC serial port to switch console port

23. Advantages of RIP over ospf
     -is less complex to configure
     -demands fewer router resources

24. What are the characteristics of 802.1Q protocol?
      -it modifies the 802.3 frame header, and thus requires that the FCS be recomputed.
      -it is a trunking protocol capable of carrying untagged frames.

25. Which PPP sub protocol negotiates authentication options?
       LCP

26. Which two statements apply to dynamic access lists?
       -you can set a time based security policy.
       -they are used to authenticate individual users.

27. Which command helps a network administrator to manage memory by

      displaying flash memory and NVRAM utilization?
     -show file systems

28. Which ieee standard protocol is initiated as a result of successful DTP completion

      in a switch over fastethernet?
      -802.1Q

29. Which Ipsec security protocol should be sued when confidentiality is required?
      -ESP

30. Maximum no of equal cost paths that can be placed into the routing of a cisco

      ospf router?
      4

31. ip default-gateway command only used for the devices which does not support

      ip routing ie switches. In cisco IOS routers ip routing is enabled by default .to use

      ip default-gateway in cisco routers we need to disable ip routing.

      The major difference between these two options is that configuring a static
      default route only defines a default route for the router you're configuring it on,

      while ip default-network will propagate the route via its routing protocol.

32. Three features of IPv6 protocol
      -plug and play
      -no broadcast
      -auto configuration

33. Which command shows you active telnet connections?
       show sessions

34. Which command alllows you to verify encapsulation type(cisco or ietf) for a

      frame realy link?
      -show frame-relay map

35. Which device might be installed at a branch office to enable and manage an

      IPsec site-to-site VPN?
      -cisco adaptive security appliance


36. sh interface will give line , protocol, dlci and lmi info

37. sh cdp interface will give cdp enabled interface on your router.

38. no frames are transmitted or received on blocked ports

     bpdu's are still received on blocked ports.

39. bpdu's are used to send conf messages using multicasts frames.

40. sh hosts --will show the host name resolved to an ip address

      on the router.

41. inbound access lists--incoming packets are processed before being

      routed to an outbound interface. No router lookup.

42. outbound access lists--incoming packets are routed to the outbound

      interface and then processed.

43. isl operates in a point-to-point environment, operates at layer 2,

      header contains 15 bit vlan id.

44. vtp info are sent over vlan 1

45. catalyst 1900 can have 64 vlans with a separate spanning tree

      per vlan.

46. factory default vlans--1,1002,1003,1004,1005

47. sh span tree vlan number---spanning tree information for a vlan.

48. Ethernet lacks a mechanism to recognize and eliminate

      endlessly looping packets.

49. stp-on a root bridge each port is a designated port.

      bridge id=bridge priority + mac address.

50. tcp header is 20 bytes , udp has 8 bytes header

51. dns uses udp for name resolution, and tcp for server zone transfers.

52. networks 10.0.0.0,172.16.0.0 thru 172.31.0.0 , 192.168.0.0 are

      reserved address and not used in public network.

53. term ip netmask-format {bitcount|decimal|hex}

      display format for netmask for the current session.

       config-line)#ip netmask-format {bit|decimal|hex}

54. cdp run is not available on 1900 switches.

55. snmp operate at application layer.

56. sh ip protocol----all routing protocols on the router.

57. Socket is made up of--layer 4 protocol, port number ,ip address.

58. cdp will provide info abt--identifier, platform and address.

59. bridge priority and bridge id ---are the factors that determine the

      election of a STP root bridge.

60. vtp info are flooded thru a vtp domain every --5 minutes.

61. each port on catalyst 1900 cannot have unique ip address for

      in band management.

62. cdp packets are sent to neighboring device every 60 secs by default.

63. split horizon with poison reverse. ---the routing protocol advertises

      all routes out an interface, but those learned from earlier updates

      coming in that interface are marked with infinity..

64. access list are default to outbound.

65. an eigrp metric is represented 256 times an igrp metric.

66. rip , igrp and eigrp can utilize 4 equal costs links.

67. NETBIOS operates at layer 5 session.

68. CIDR allows internet service providers to reduce the number of routes

      carried in their routing tables.

69. sh config--startup config.

70. frame-relay map statement , frame-relay interface-dlci statements,

      inv arp is used by a router to assign layer 3 addresses to layer 2.

71. auto summary cannot be disabled by rip version 1 and igrp.

72. ip subnet-zero----is used to enable the use of zero subnet.

73. vtp supports password authentication.

74. protocol tunneling----to transport multiprotocol over single protocol

      backbone ,overcome discontiguous network problems, to allow virtual

      private networks.

75. ip summary-address eigrp 100 ip mask  ---will summarize the network

      for the the AS 100

76. max distance of 10basetx=100 mtrs

77. sh terminal ---will give u the history size on the router.

78. to resolve a name todd --ip host todd ipaddress

77. sh running will show the interfaces where access lists are assigned.

      sh ip int , sh ipx int --will do the same.

78. tftp-server system image name---is used to configure a router so

      It can become a tftp server host for a router system image that is

      run in flash.

80 .max distance of fast Ethernet=100 mtrs.

81. when an Ethernet link is powered on --link speed and link duplex

      are provided by the auto negotiation mechanism.

82. cisco router Ethernet int can use MAC address other than the burned

      in address.

83. set vlan 100 4/1-24 ----will assign ports 1-24 on module 4 to vlan 100

84.

·       dns uses both tcp and udp.

·       each vlan will have its own root bridge.

·       atm and faddy are capable of vlan tagging.

·       atm is connection oriented.

·       sh process ---displays routers process

·       ios version 11.2 --lmi was first auto sensed.

·       auto summary is enabled by default for rip v 2 and igrp.

85. Named type of access list allows more than 99 standard and 100

      extended access list to be created.

86.

·      cdp is not a subset of snap protocol.

·      cdp operates at data link layer.

·      no cdp run---disables cdp for all the interfaces on a router

·      auto summary cannot be disabled by rip v 1 and igrp.

·      write erase -on a router is same as delete nvram on 1900

·      subnet mask borrows bits from host field and designate them to subnet field.

·       Vlan membership --static and dynamic

·       VMPS-vlan  management policy server -creating MAC host table

·       vlan has two types of links-- access and trunk

·       access link--one vlan ,unaware of vlan membership

87.

·       network 10.11.12.13 ---will advertise the network on a router with

rip , igrp and eigrp enabled.

·       ppp multilink --will enable ppp multilink on a cisco bri interface.

·       sh span tree 100 ---will display the MAC address of the root bridge for vlan 100

·       two named access lists with the same name can be used on diff routers

in the same autonomous systems.

·       no debug all , and , undebug all ---cancel all debugging on a router.

·       ppp has a architected type field to determine the type of encap and

also performs error correction if chosen.

·       show compress ---shows the compression ratio.

·       frame relay is multiaccess--more than two device can attach to a medium.

·       there is a single dlci in a header--no source and destination dlci.

·       in frame relay split horizon is enabled for point to point interface.

·       ip split horizon interface ---can be used to change the default value.

·       OUI is the unique number assigned by IEEE for NIC manufacturers.

88.

·       snmp-server enable traps---allows syslog messages to be sent as

snmp traps.

·       to remove an access list 101(out bound) from a router

---no ip access-group 101 out

·       net bios operate at session layer.

·       cisco routers cannot read and write files from flash memory to ftp

·       server.

·       ospf and eigrp support variable length subnet masks.

·       sh cdp nei det- will give the IOS version of the neig device

·       sh cdp traffic- gives the interface traffic

·       sh cdp interface -shows also the encapsulation of the line,timer

and holdtime

·       Dynamic trunk protocol (DTP) is used to send trunk info across

802.1q links. Its a PPP protocol.

·       vtp pruning is used to avoid broadcasts and multicasts from getting

into trunk links that need not need the info.

·       vlan 1 can never be pruned as it is the administrative vlan.

·       all switches are vtp server by default

89.

·       ip route 0.0.0.0 0.0.0.0 ipaddress -is the cmd for conf default route

·       adm distances C=0 , S=1 , RIP=120 ,IGRP=100 , EIGRP=90 , OSPF=110

·       RIP version 1 is classful routing.

·       IGRP is cisco prop , max hop count of 255 , default of 100,uses

·       band width and delay of line as default.

·       RIP timers 30-90-240  IGRP 90-270-280-630

·       AS number can be from 1-65535

·       igrp uses classful routing , no subnet mask sent

·       sh ip protocols -gives the routing protocols configured , along

with the timer values, s

·       debug igrp [events|transactions]--

events-igrp routing info running on the network

·       u cannot telnet from a 1900 switch if configured.

·       sh ip --will give the default ip configuration of the switch.

·       100basetx default is auto , 10baset default half duplex.

·       default conf for 1900--cdp enabled , def gateway 0.0.0.0

·       port secure mac-max-count 1 - for only one mac address for a port.

·       sh port system --shows the default switch mode. (fragment free)

  

90.

·       switching mode option---will change the default switching mode

·       vlan number name vlanname ---to configure vlan

·       vlan-membership static|dynamic vlannumber--assigning ports to vlan

·       sh vlan , sh vlan-membership ---will give ports assigned to vlans

(config-if)#no trunk vlan number --clearing the trunk vlan.

·       58.sh trunk trunknumber [options] --to see what vlans are allowed on

trunk ports.

·       (config-subif)# encapsulation isl vlannumber,ip address ---for changing the

encapsulation type.

·       sh vtp--- for verifying the vtp information.

·       if vtp pruning is set on server its set on the whole  domain.

·       spanning tree protocol is transparent to end stations.

·       in default settings the switch with the lowest MAC add is the root.

·       priority of switch is a  parameter to decide root switch.

·       STP states .blocking , listening,learning,forwarding, disabled.

·       ports stabalize to either forwarding or blocking state.

·       blocking state does not forward a frame.

91.

·       sh ipx servers ---shows the content of sap table in the router.

·       sh ipx route---shows the ipx routing table the router knows

·       ipx max-path number(till 64)--load balancing on routers.

·       sh ipx traffic--shows the rip and sap packets transmitted and recd

by the router.

·       sh ipx int intno.----gives the ipx status of that interface along with

the ipx addresses.

·       debug ipx routing [activity|events]--rip routing activity and events.

·       debug ipx sap activity---sap activity on ur router.

·       two PDU's at network layer---data and route

·       cut thru and fragment free have fixed latency time

·       it takes 50 secs for a switch port to go from blocking to forwarding.

92.

·       .up arrow key gives the previously entered cmd.

·       clear mac-address-table dynamic

·       to see transmit and recv statistics of vtp on 1900--sh vtp stat.

·       IEEE standard for stp 802.1d

·       udp works at host-to-host layer of DOD model

·       wins translates the netbios names

·       cdp is enabled by default , updates 60 secs , hold time 180 secs.

·       after a router boots by auto install , it first resolves its hostnames

it then looks for hostname-config to get specific configuration.

·       sh int---will only give the hardware address of an interface.

·       sh int --will give dlci and line speed for a frame relay.

·       cdp timer--will change the freq of cdp broadcasts

·       u can see router running conf in privileged mode.

·       local loop--link between demarc and the CO

·       igrp advertises three types of route..interior, exterior and system

·       sh ip protocol--will give the routing protocols on a router

·       for full duplex --loop back and collision detection are disabled.

·       ip host ipaddress name --to create host table         

·       sh protocols --will show the routed protocols.

·       to delete the configuration stored in nvram--erase startup.

·       lan switch mode that keeps crc to minimum but has a fixed latency

·      rate---fragment free.

93.

       Command to set the clock
       #clock set 10:45:00 1 June 2011

       To verify the new clock setting type.
       # show clock

       Type terminal history size 5  to set the command history size to 5.

       Type show terminal to see the terminal history size.

       Type show history to view your last five commands

       Type terminal no history to disable the command history but Confusingly, 

       no terminal history size resets this to the default, which is 10 commands.

       Type show flash to verify the amount of free flash memory you have.

       Type copy flash tftp to backup your IOS image to a TFTP server.

       Type show cdp to see the global CDP information.

       Type show cdp neighbors  to view connected devices.
       Note what information is displayed.
       Hostname, local interface, capability, platform, neighbor's device port Id

       If you want to find out more information on each directly connected device type 

       sh cdp neighbors detail

94. To display just IP addresses of each directly connected device type show 

      cdp entry * protocols

95. To display the IOS versions of each directly connected device type 

      show cdp entry * version

96. Note: show cdp neighbors detail has the same output as show cdp entry *

97. Blocking        No frames forwarded, BPDUs heard
      Listening       No frames forwarded, listening for frames
      Learning        No frames forwarded, learning addresses
      Disabled        No frames forwarded, no BPDUs heard

98. 802.11b   ==     2.4GHz, 11Mbps

      802.11a  ==      5GHz, 54Mbps

      802.11g   ==     2.4Ghz, 54Mbps
      ROM monitor  == Used for testing and troubleshooting
     

     Protocol used to update switches about new or old VLANs

     VLAN Trunk Protocol (VTP)


99. Used to identify which frame belongs to which VLAN == Frame tagging
      802.11n  ==      2.4GHz or 5GHz, 300Mbps
      WEP == Original IEEE wireless security standard. Easily hacked.

      WPA Wireless security standard created by the Wi-Fi Alliance. Uses a dynamic

      key for greatly improved security over WEP. Interoperable with different

      vendors products.
 
      WPA-2 Ratified by the IEEE in 2005 who named it IEEE 802.11i. Uses

       AES encryption.

100. Serial encapsulation to use to connect to a non-Cisco router PPP for serial links
        Command to display hosts table == show hosts.