8/19/2019 CNIS Tech Interview Answers

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13 Things To Know For a CNIS/Administration Professional Interview.

1. What is MTU?MTU stands for maximum transmission unit. This is the largest PDU

(protocol data unit) that the layer can pass on. There are certain standardsithin a protocol hich ma!e it so that the MTU can "e manipulated. #ot allprotocols hoe$er allo the MTU to "e edited.

%. What is a &P#?&irtual pri$ate netor!s are logical netor!s created "eteen pieces

of e'uipment. The most common instance of this is hen a user is at homeand needs to connect to their "usiness netor! in order to access the"usiness resources.

. What is a &*+#?&*+# stands for &irtual *ocal +rea #etor!. *ocal area netor!s are

typically housed on 1 sitch. This allos a group of hosts to thin! that theyare on the same "roadcast domain e$en though they may or may not "e inthe same physical area. ,- de$ices can "e connected through dierentphysical sitches "ut "e tric!ed into thin!ing that they are connected to one./t is a similar concept as su"nets.

0. What is a metric?+ metric is a unit of measurement hich helps a router determine the

"est path possi"le for data. There are multiple metrics hich can "e used andcom"ined in order to determine the "est path such as measuring lin! useconnection speed relia"ility "andidth current load hops etc

2. What is +3P43+3P?

+3P stands for +ddress 3esolution Protocol. 3+3P stands for 3e$erse+ddress 3esolution Protocol. +3P uses a re'uest for an /P address andtranslates it to a M+5 address. ,o computer + might say / ant to spea! ith16%.178.1.22 and the +3P ta"le ill tell it that 16%.178.1.22 is at99:%:+;:6+:;5. 3+3P or!s the exact opposite. ,omething may say . What is a M+5 address?

M+5 stands for Media +ccess 5ontrol. This is a uni'ue identier hichis assigned to netor! interfaces. Whether they are ired or ireless eachhas its on M+5. This pertains to phones computers laptops T&s etc. Theyare formed "y regulations made "y the /@@@.

8. What is a "roadcast storm?+ "roadcast storm is essentially li!e a for! "om" on sitches. + node

ill as! sitch 5 hat the address for node + is. /f sitch 5 doesnt !no itill as! another node that node then as!s another. @ach of those nodes reA

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"roadcast the message from all of the pre$ious nodes therefore sendingsimultaneous responses and re'uests to the pre$ious nodes hich then inturn "roadcast out their anser or 'uestion. This ends up causing a largeamount of congestion on the netor!.

6. What is the purpose of &33P?

&irtual 3outer 3edundancy Protocol (&33P) as designed to increasethe a$aila"ility of the default Bateay. This ill allo it to pro$ide ser$ice tohosts on the same su"net. This increased relia"ility is achie$ed through theprocess of ad$ertising a $irtual router hich the nodes can utiliCe. Thisre'uires multiple 3outers to pull o. -ne ill act as a master and the other isa sla$e hich ta!es o$er if the master goes don.

1.What is a runt Biant and collision?+ runt is a pac!et hich is typically malformed causing it to "e too

small to tra$erse the netor!. @thernet and other protocols often re'uirethat pac!ets "e a minimum num"er of "ytes in order to mo$e across thenetor!.

+ Biant is the exact oppositeE it is a pac!et hich is too large to mo$eacross the netor! in a certain protocol. These also are caused "y faultye'uipment or mal formed pac!ets. These hoe$er can "e created "y accident"y a person ith malicious intent accidentally setting a setting too high hiletrying to Food a netor!.

With regards to all traGc o$er the netor! nodes determine hen thenetor! is a$aila"le .,ometimes to nodes in dierent places try to senddata at the same time. When this happens the same result ill happen as ifto people are trying to al! into the same house door at the same time.;+#BH + collision.

11.Descri"e a T5P connection se'uence.

ay handsha!e is the more common term for this. +5I ,J# ,J#+5I. These are +c!noledgement ,ynchroniCation and ,ynchroniCation+c!noledgement. ,o machine one says

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to the corresponding machine "ased on its sitch ta"le. The sitch ta"le is ata"le hich consists of a physical address and hich sitch port the addressis plugged into.

*i!e a sitch a hu" connects multiple *+# segments and sends traGcfrom one place to another. The dierence though is that a hu" sends alltraGc to all of its ports. ,o e$en if message xyC is supposed to go to the

computer on port 1 it ill "e "roadcasted to port 1 % 0 2 7 > and 8. -rhoe$er many ports you ha$e.

3outers connect dierent segments of netor!s as opposed todierent segments of *+#s. They also connect dierent netor!s to othernetor!s. 9or instance you can ha$e a 1>>.102.%11. netor! connected to a1>>.122.%0. netor!. They use the actual /P to determine here to directtraGc. What is dierent a"out routers though is that they can "e securedmuch more dynamically than sitches (hu"s ha$e $irtually no security). 9orinstance a router connects a home netor! to the /,P and performs #+T(netor! address translation) as a security feature.