CCNA TIPS -4

1. To see how many management packets have been sent to the frame realy 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

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

dead interval will change automatically once there is change in hello

We need to change hello interval on both routers which are going to form beighbor otherwise adjacency won't happen.

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

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.

attempt will only seen in NBMA

Timer default for point to point are 10 sec and 40 sec but for etherent and non broadcat NBMA hello is 30 and dead is 120 secs.

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

running both Ipv4 and ipv6 on a router simultaneoulsy is known as  dual-stack tunneling.

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

antispyware
detects software designed to capture sensitive information and removes it from the computer

anitvirus
prevents known malicious programs from being installed on workstations

IDS
identifies malicious network traffic and alerts network personnel

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

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.

Rollover
PC serial port to switch console port

point to point advantage = quality
point to point disadvantage = limited flexibility
ckt switched advantage = cost
ckt switch disadvantage = low speed
packet switched advantage = efficient
packet switched disadvantage = more complex

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

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 capabe of carrying untagged frames.

Which PPP subprotocol negotiates authentication options?
LCP

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

Which command helps a network administrator to manage memory by displaying flash memory and NVRAM utilization?
-show file systems

Which ieee standard protocol is initiated as a result of successful DTP completion in a switch over fastethernet?
-802.1Q

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

mximum no of equal cost paths that can be placed into the routing of a cisco ospf router?
4

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 disbale 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.

Three features of IPv6 protocol
plug and play
no broadcast
autoconfiguration

Which command shows yout active telnet connections?
show sessions

Which command alllows you to verify encapsulation type(cisco or ietf) for a frame realy link?
-show frame-relay map

which device might be installed at a branch office to enable and manage an IPsec site-to-site VPN?
-cisco adaptive security appliance

In which circumstance are multiple copies of the same frame likely to be transmitted ina switched LAN?
-when a dual ring topology in use

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

2.sh cdp interface will give cdp enabled interface on ur router.

3.to view dlci numbers configured on ur router.

  sh interface and sh frame-relay pvc

 there is no command as sh frame-relay dlci.

4.no frames are transmitted or received on blocked ports

  bpdu's are still received on blocked ports.

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

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

  on the router.

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

  routed to an outbound interface. No router lookup.

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

  interface and then processed.

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

  header contains 15 bit vlan id.

10.vtp info are sent over vlan 1,

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

   per vlan.

12.vtp v1 supports only Ethernet, vtp v2 supports ethernet and token ring.

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

14.vlan number name new-name --modifying vlan name.

15.sh span tree vlannumber---spanning tree information for a vlan.

16.ethernet lacks a mechanism to recognize and eliminate

   endlessly looping packets.

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

   bridge id=bridge priority + mac address.

18.1900 factory default ip address is 0.0.0.0.

19.default gateway on 1900 is the address of the router.

20.auto---on or desirable ,desirable --on , desirable or auto.

21.sh interface--for fcs or late collision errors.

22.for port security--port secure max-mac-count # ---default is 132.

23.sh mac-address-table security , address-violation [suspend|ig|dis]

24.tcp header is 20 null , udp has 8 bytes header

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

26.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.

27.in 12.0 ios , routers by default will not forward an all subnet

   broadcast , use ip directed-broadcast to enable this feature.

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

    display format for netmask for the current session.

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

30.cdp run is not available on 1900 switches.

31.on a 1900 --sh cdp nei det , is available . there is no- -sh cdp

   entry * --on a 1900

32.sh cdp traffic --is not available on 1900.

1.snmp operate at application layer.

2.lat ,netbeui, sna are non  routable , appletalk is routable.

3.to remove an image from flash permanently--squeeze.

4.ip domain-name-----aasigns domain name to a router.

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

6.socket is made up of--layer 4 protocol, port number ,ip address.

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

8.to see status of channel 1 on bri0 ---show interface bri0:1

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

  election of a STP root bridge.

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

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

   in-band management.

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

13.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.

14.debug ip packet list 101--would enable debugging against packets

   matching access list 101.

15.isdn uses out-of-band signaling.

16.multiple boot system command--the first command found in the conf

  is processed.

17.appletalk address --24 bits.

18.cisco 2503 requires external NT1 device.

19.access list are default to outbound.

20.max age timer must expire before determining the topology has changed.

21.address-violation----ignore the violation,disable the port, suspend

  the port.

22.EIGRP will be marked as D

23.debug ipx routing activity---all ipx rip updates sent and recd.

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

25.set vlan 301---creates vlan on cisco catalyst switch.

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

27.copy NorAm tuft ---saved conf to tftp.

28.NETBIOS operates at layer 5 session.

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

   carried in their routing tables.

30.sh config--startup config.

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

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

32.ipx per-host-load-share---disables per packet load balancing using ipx

   when multiple routes to same destination are available.

33.NAT is not proprietary of Cisco technology.

34.FRF.9 is supported in hardware by the compression service adapter

   and versatile interface processor.

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

36.ring-speed -- is used to configure the speed of token ring on a

   cisco router.

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

38.rip version 2 ---supports authentication, provides multicasts routing

   updates , transmits subnet mask with route updates.

39.vtp supports password authentication.

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

  backbone , overcome discontiguous network problems, to allow virtual

  private networks.

41.when an isdn bri comes up for the first time ---terminal endpoint

  identifier is  assigned to it by the isdn switch.

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

   for the the AS 100

43.max distance of 10basetx=100 mtrs

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

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

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

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

47.to set the switch type on a isdn

   (config)#isdn switch type, (config-if)#isdn switch type.

48.tftp-server system image_name---is used to configure a router so

   it can become a tftp server host for a router system image

   run in flash.

49.max distance of fast Ethernet=100 mtrs.

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

  are provided by the auto-negotiation mechanism.

51.when an Ethernet network has collisions -back off algorithm determines

   the next time the transmitting host can transmit a signal.

52.syslog messages in a vty session as they r generated

   -- terminal monitor.

53.isdn u ---built in NT1

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

  in the address.

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

56.dns uses both tcp and udp.

57.each vlan will have its own root bridge.

58.atm and faddy are capable of VLAN tagging.

59.atm is connection oriented.

60.sh process ---displays routers process

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

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

63.a vtp domain with no defined domain name will accept the domain name

  of any other vtp advertisement.

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

   extended access list to be created.

65.there are 34 pins defined for v.35 interface.

66.cdp is not a subset of snap protocol.

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

68.network 10.11.12.13 ---will advertise the network on a router with

   rip , igrp, and eigrp enabled.

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

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

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

   in the same autonomous systems.

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

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

74.cdp operates at data link layer.

75.rip version 2 provides multicasts updates.

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

77.lapb , hdlc , ppp all provide error detection.

78.ppp has an architected type field to determine the type of encap and

   also performs error correction if chosen.

79.show compress ---shows the compression ratio.

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

81.LAPF(Q.922-A) --is the basic frame relay header and trailer,it includes

          dlci, fecn, becn, de bits.

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

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

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

84.sh controllers bri number---shows layer1 stats and status for B and D

   channels.

85. debug isdn q921|q931 ---lists isdn layer 2 or layer 3 messages.

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

87.RFC 1490 added 2 byte protocol field to frame relay.

88.ip rip send|receive version 1 ---allows rip v 2 to send |recv rip v1

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

90.0-1023 are the allowable values for dlci.

91.dialer in-band---used for non isdn interfaces.

92.cisco router with isdn U has a built in NT1

93.multicasts are forwarded by transparent bridges.

94.confreg and o/r are the rommon commands valid for configuration reg

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

   snmp traps.

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

    ---no ip access-group 101 out

97.segmenting a network with a switch decreases the size of collision domains.

98.net bios operate at session layer.

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

   server.

100.ospf and eigrp support variable length subnet masks.

---- 

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

2.sh cdp nei will give a)device id b)loc int c)holdtime d)capability

  e)platform f)port id

3.only sh ipx int and sh protocol will give ipx address

4.sh cdp traffic- gives the interface traffic

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

  and holdtime

6.ip host hostname ipaddress - is used to resolve host name to ip address

7.no ip domain lookup - shutting down default domain lookup

8.sh version -will give the config reg value.

9.vlan membership --static and dynamic

10.VMPS-vlan  management policy server -creating MAC host table

11.vlan has two types of links-- access and trunk

12.access link--one vlan ,unaware of vlan membership

13.trunk links -- multiple vlans , identification tech -isl and 802.1q

                LANE, 802.10(FDDI)

14.802.1q -inserts field into the frame for identification. Used when

   connecting cisco switch to a different brand switch.

15.LANE--multiple vlans over ATM

16.802.10 (FDDI) -vlan over fddi , uses a SAID field in the frame header.

17.ISL--tagging allows vlans to be multiplexed over a trunk link thru an

 external encapsulation , both full and half duplex ,26 bytes header,

 4 bytes FCS trailer. ,

18 trunk links are 100-1000 Mbps, can carry 1-1005 vlans info,

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

   802.1q links. Its a PPP protocol.

20.client mode of vlan is not saved in nvram

21.transparent mode of vlan does not participate in vtp domain , does not share info

   with other switches. Only forwards vtp info across switches.

22.vtp pruning is used to avoid broadcasts and multicasts from getting

    into trunk links that need not need the info.

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

24.all switches are vtp server by default

25.ip classless -cmd shd be used if u r using default route

26.ip route 0.0.0.0 0.0.0.0 ipaddress -is the cmd for conf default route

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

28.RIP can perform a load balance if the hop count is same .max is 6

29.pin hole congestion- two diff links with same hop counts will be treated

as same

30.RIP updates every 30 secs

31.holddowns use triggered updates to reset

32.RIP version 1 is classful routing.

33.passive-interface -this cmd does not allow ur rip broadcasts to get

to the internet but u interface can receive the broadcasts.

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

 bandwidth and delay of line as default.

35 .RIP timers 30-90-240  IGRP 90-270-280-630

36.need to mention AS no. for igrp conf.

37.igrp uses bandwidth to decide load balance, can balance up to 6

   unequal links.

38.cmd used for load balancing --variance <1-128> and traffic share-

   balanced or min.

39.AS number can be from 1-65535

40.igrp uses classful routing , no subnet mask sent

41.sh ip protocols -gives the routing protocols configured , along

   with the timer values,

42.debug ip rip--shows the route updates thru the router on the console.

43.debug igrp [events|transactions]--

events-igrp routing info running on the network

transactions-from neigh routers asking  abt updates and broadcasts

             sent by ur router.

44.u cannot telnet from a 1900 switch if configured.

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

46.configuring port duplex --duplex full

47.100basetx default is auto, 10baset default half duplex.

48.default conf for 1900--cdp enabled , def gateway 0.0.0.0

                switching mode fragment free, spanning tree enabled.

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

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

51.switching mode option---will change the default switching mode

52.vlan number name vlanname ---to configure vlan

53.vlan-membership static|dynamic vlannumber--assigning ports to vlan

54.sh vlan, sh vlan-membership ---will give ports assigned to vlans

55.1900 runs the DynamicISL encapsulation method.

56.(config)#trunk [auto|desirable|nonnegotiate|on|off] --is used

      to configure trunks.

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

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

      trunk ports.

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

    encapsulation type.

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

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

62.spanning tree protocol is transparent to end stations.

63.switch info is passed thru BPDU's

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

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

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

67.ports stabilize to either forwarding or blocking state.

68.blocking state does not forward a frame.

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

70.sh ipx route---shows the ipx routing table the router knows

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

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

         by the router.

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

    the ipx addresses.

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

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

76.two PDU's at network layer---data and route

77.cut thru and fragment free have fixed latency time

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

79.when a switch recs a multicast frame it floods the network with the

   frame looking for the device.

80.up arrow key gives the previously entered cmd.

81.0 X 0101 ---router boots from ROM

82. #clear mac-address-table dynamic

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

84.BECN in frame relay tells the router to slow down if the network is congested.

85.IEEE standard for stp 802.1d

86.hightest latency --store and forward. lowest --cut thru

87.udp works at host-to-host layer of DOD model

88.802.2 uses dsaps and ssaps.

89.wins translates the netbios names

90.terminal no editing----disable the advanced editing features for

   cisco router.

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

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

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

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

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

95.cdp timer--will change the freq of cdp broadcasts

96.u can see router running conf in privileged mode.

97.local loop--link between demarc and the CO

98.T ref is between NT1 and NT2

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

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

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

102.ip host ipaddress name --to create host table         

103.sh protocols --will show the routed protocols.

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

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

    rate---fragment free.