CCNP300-115交换疑问题目，或者题库答案不一样的题目，有兴趣的朋友一块研究下。

nbwinpe

题目编号是根据6月12号的题库

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QUESTION 127
- ~6 C. G1 H+ h, a* k2 BOnwhich interface can port security be configured?
' F5 K' h8 q: r$ kA. static trunk ports
B. destination port for SPAN
C. EtherChannel port group
0 {4 Y9 y8 c2 n) M, |/ ?D. dynamic access point
2 d0 K+ w0 ~7 n+ vCorrectAnswer: A
, g0 w/ h- P% tSection:part3
& @7 m% H( T7 y# G2 c# mExplanation

trunk ports确实可以实现port-security，但是port-channel下不能，及时打问号有这个命令，但是敲不出来。从文档来看A和C都不能用，所以我的认为答案选D

Port SecurityGuidelines and Restrictions

Follow theseguidelines when configuring port security:

A secure portcannot be a trunk port.

A secure portcannot be a destination port for Switch Port Analyzer (SPAN).

A secure portcannot belong to an EtherChannel port-channel interface.

A secure port andstatic MAC address configuration are mutually exclusive.

QUESTION 194
/ o% t6 l: B9 T8 W8 r/ AA physical switch port is part of an EtherChannelgroup.What happens while the same port is configured as a SPAN destination?
A. The port forwards traffic in the EtherChannel groupand acts as a SPAN source simultaneously
/ \3 i) m7 b* @4 xB. The operation is not allowed as an EtherChannelmember cannot be a SPAN source port
, x3 o# t) R3 E+ }C. The port is put in the errdisabled state and canonly be reenabled manually
D. The port is removed from the EtherChannel
Correct Answer: B
+ M5 y; x& [% |' i( h3 lSection:part4
$ W4 K. B( g1 L" R1 @Explanation
Explanation/Reference:

A destination port can be a physical port that is assigned to anEtherChannel group, even if the EtherChannel group has been specified as a SPANsource. The port is removed from the group while it is configured as a SPANdestination port

QUESTION 198
What happens if you apply this command “vlan dot1q tag native” ?
9 o' r# V+ w7 {: B8 G# vA. packet will be dropped
B. packet go to defautl vlan
C. packet go to native vlan
/ I2 {$ P' {- m4 L  D8 _D. http://bbs.hh010.com/
5 v) Q9 k0 K* _9 i8 |Correct Answer: C  我认为答案是A
Section: part4

Explanation/Reference:

Usage Guidelines

Typically, youconfigure 802.1Q trunks with a native VLAN ID, which strips tagging from allpackets on that VLAN.

To maintain thetagging on the native VLAN and drop untagged traffic, usethe vlan dot1q tag native command. The switch will tagthe traffic received on the native VLAN and admit only 802.1Q-tagged frames,dropping any untagged traffic, including untagged traffic in the native VLAN.

Control trafficcontinues to be accepted as untagged on the native VLAN on a trunked port, evenwhen the vlan dot1q tag native command is enabled.

QUESTION 215
Which statements about RSPAN are true? (Choose two.)
A. It supports MAC adress learning.
B. RSPAN VLANS can carry RSPAN traffic only.
6 j; w9 A5 |/ T8 L; kC. only one RSPAN VLAN can be configured per device.
* G! o2 ~1 |6 fD. RSPAN VLANs are exempt from VTP pruning.
E. MAC address learning is not supported.
F. RSPAN uses are GRE tunnel to transmit captured traffic.
0 H7 _4 |. A2 @/ h" L, f6 U6 S0 @Correct Answer: BC  我认为答案是BE
  ?2 o, @5 Y. u3 ^# U5 K9 [Section: part5

Explanation/Reference:

RSPAN VLAN

The RSPAN VLANcarries SPAN traffic between RSPAN source and destination sessions. It hasthese special characteristics:

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• All traffic in the RSPAN VLAN is always flooded.
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• No MAC address learning occurs on the RSPAN VLAN.
  
• RSPAN VLAN traffic only flows on trunk ports.
  
• RSPAN VLANs must be configured in VLAN     configuration mode by using the remote-span VLAN configuration     mode command.
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• STP can run on RSPAN VLAN trunks but not on SPAN     destination ports.
  

For VLANs 1 to 1005that are visible to VLAN Trunking Protocol (VTP), the VLAN ID and itsassociated RSPAN characteristic are propagated by VTP. If you assign an RSPANVLAN ID in the extended VLAN range (1006 to 4094), you must manually configureall intermediate switches.

It is normal tohave multiple RSPAN VLANs in a network at the same time with each RSPAN VLANdefining a network-wide RSPAN session. That is, multiple RSPAN source sessionsanywhere in the network can contribute packets to the RSPAN session. It is alsopossible to have multiple RSPAN destination sessions throughout the network,monitoring the same RSPAN VLAN and presenting traffic to the user. The RSPANVLAN ID separates the sessions.

QUESTION 216
When a private VLAN is configured, which mode must be configured as a routerfacing port?
) N( v& M" H& KA. isolated
8 J0 r0 _2 }# Z! h: N0 }, B! ]B. promiscuous
9 R* k: |7 p4 m) C8 M) S% qC. community
D. .host
Correct Answer: C  我认为答案是B
Section: part5

QUESTION 240
EtherChannel guard misconfig is configured on a switch, which technologysupports that
1 \5 A3 r6 g4 `+ E0 I! m# GA. LACP
B. PagP
7 F& |% H0 s2 BC. STP
" [$ \) J* U) S6 h# W; QD. Port Security
5 O) x4 F2 Y. i% r$ n2 FCorrect Answer: C   我认为答案是A.LACP
/ [2 h! o7 U! _5 w7 N+ zSection: part5

LACP可以避免由于错误配置而造成二层交换环路；开始LACP后，在两端没有成功沟通的情况下，EtherChannel是不会建立的。不过这样的沟通机制引入了更大数据报头和更长初始化延时。配置‘On’可以消除延时，但是如果配置失误的话可能造成严重后果。

http://blog.csdn.net/ziyuanzhao/article/details/23674207

QUESTION 251

VMPS question – a dynamicaccess port is member of which VLAN by default?

A. VLAN 1 is thedefault VLAN

B.http://bbs.hh010.com

C. none until theport VLAN is determined

D.http://bbs.hh010.com

Correct Answer: A

Section: part6

Explanation

Explanation/Reference:

如果在文件列表中找到MAC地址，交换机就将端口分配给列表中该MAC所对应的VLAN。所有列表中没有的话，交换机就会将该端口分配给默认VLAN（假设已经定义了默认VLAN）。如果在列表中没有MAC地址，而且也没有默认VLAN，端口将不会被激活。 本实例将述的就是基于MAC地址的动态VLAN。

其中（假设已经定义了默认VLAN）说明默认是没有定义“默认VLAN”所以我认为答案应该是C. none until the port VLAN is determined

QUESTION 255
question in regards to an EtherChannel misconfiguration.
A. LACP
B. PortFast
/ w* k# G3 J) j; M  FC. PAGP
D. STP
Correct Answer: D   我认为答案是A. LACP
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QUESTION 267
If all devices on an EtherChannel are sending traffic to a single MAC address,which two methods of load
3 a# |; m6 @5 t9 S+ _balancing on the EtherChannel are preferred? (Choose two.)
A. destination-MAC

B.src-dst-MAC
C. destination-IP
3 C; b9 f, F; }( t# q7 K$ f5 O. |D. source-MAC
7 f2 G5 S- [; gE. source-IP
Correct Answer: BD 我认为答案是D. source-MAC和E. source-IP
Section: part6

QUESTION 274
Diagram is: with 1 core, 2 DSW connected with EtherChannel, 2 ALSW, 2 PCs perALSW. Per diagram
9 X2 q. W% u4 S& c4 ccurrent root for VLAN 10 is DSW2.
: W/ J6 s0 I  h$ B" T; ]0 FQuestion is how to make DSW1 the primary root for VLAN 10. (Choose two.)

A. DSW2: change bridge priority to 61440 (highest).
B. DSW1: change bridge priority to 4096 (lowest).
C. DSW1: change port priority but in global configuration mode.
D. DSW1: change bridge priority but value is 0.
E. DSW1: change bridge priority but command is priority root.
Correct Answer: BE 我认为答案是B和D
Section: part6

QUESTION 290
, b( m( @* M: M3 d( KWhat is the default mode for LACP EtherChannel when configured?
8 P; Z" A: j3 s* a  YA. On
  m, Z: r2 d6 j2 m  l, [+ _B. Active
" y4 A) W) n. O7 B& G( L+ _C. Passive
D. Desirable
E. Off
4 ]" n' T$ F" o$ D/ K) ICorrect Answer: C  我认为答案是A. On
Section: part6

QUESTION 300
: o1 Z3 K' [& o5 X; Z. p  SWhich two operational attributes can be checked forEtherChannel ports
that are in err-disabled state?
A. Port mode
B. Port cost
C. Duplex
D. DTP
8 [4 _2 u6 n% m% EE. VLAN
Correct Answer: AE 我认为答案是A和C
9 t6 q3 ]' r( G' GSection: part6

SW1(config)#spanning-treeetherchannel guard misconfig

EtherChannel Guardis a way of finding out if one end of the EtherChannel is not configuredproperly. This could be that there are some parameters not matching up such asduplex and speed. Or it could be that one side is a trunk and the other isn’t.

When there is amisconfiguration found, the switch will place the interfaces in error-disabledstate and an error will be displayed.

QUESTION 303
0 ^9 w. n/ K+ o) X8 ~6 IWhatis the value of the TPID/tag protocol identifier of QinQ?
A. 0x8a88
B. 0x8100
C. 0x8b45
9 F8 P6 w3 @+ p* b) c- L% ND. 0x8200
; o, d2 h" o+ RCorrectAnswer: A
Section:part7
: _2 J1 u1 S. U) ]: k, l' c/ y( vExplanation
$ D9 p3 R7 L: r' b, J' C7 KExplanation/Reference:
  G" [6 ?" X/ A/ @% x/ ^1 \Ans: A

在802.1Q中规定TPID（Tag Protocol Identifier）的EType的值为0x8100。在QinQ封装中，各个设备厂商的内层TPID的EType的值为0x8100，但是对于外层TPID的EType，各个厂商所使用的值不相同。

         

VLAN的标签也可以是上层嵌套的，这种VLAN方式一般在运营商的网络中采用。这种VLAN可以把多个客户的VLAN在划分在一个大的VLAN中以区别不同的业务。VLAN tag 从外到内逐步解析。此时外层的 VLAN TPID可以标记为9100、9200或者9300。根据802.1ad，由运营商的外层 VLAN TPID 被定义为88a8。

QUESTION 306
Which two configurations cause the frames to be tagged? (Choose two.)
) i# [# f. f% h: u9 X5 BA. interface gi 0/1.116 encapsulation dot1q
; U; ?7 P  X5 _& zB. trunk allowed vlan 116
C. interface with access and voice VLAN configured to 116
D. NA
Correct Answer: AB 我认为答案应该是A和D ，ISL
( [( w% E% j2 R& eSection: part7

QUESTION 308
EtherChannel load balancing with an exhibit.
SERVER SERVER
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  |# u2 k. q$ @8 h0 ||||||||||||
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|
# O' S% F6 [$ ?: X9 W0 T' Z4 j+ WHOST
" y% w1 o. h  ?8 RWhich EtherChannel load balancing algorithm should be used to optimize theEtherChannel links
between switches?
; I& g5 {7 X& O& _6 c3 g( PA. Source MAC
7 Q9 t( C! u( g3 TB. Source-dest MAC
% [! F  |" I0 y* G9 U& lC. Destination IP
D. Destination MAC

Correct Answer: A   我认为答案是D. Destination MAC
: N1 M: o1 l$ m  \, @6 S& s/ ZSection: part7

QUESTION 317
! L' K7 ?3 _5 @# eAquestion about the port number and multicast address of VRRP.
/ o4 w4 t* e' j(CONCEPT ONLY)
A. VRRP uses multicast address 224.0.0.18 and uses UDPport 112.
B. na
C. na
D. na
CorrectAnswer: A
! @5 g: D$ |& `4 cSection:part7
2 c# B- b6 Y" t  F9 XExplanation/Reference:

1.  HSRP——封装在UDP数据中，使用UDP端口号1985，多点广播地址为224.0.0.2

   VRRP——使用IP报文作为传输协议，协议号为112，使用组播地址224.0.0.18

Advertisementprotocol—Uses a dedicated Internet Assigned Numbers Authority (IANA) standardmulticast address (224.0.0.18) for VRRP advertisements. This addressing schememinimizes the number of routers that must service the multicasts and allowstest equipment to accurately identify VRRP packets on a segment. IANA hasassigned the IP protocol number 112 to VRRP.

QUESTION 333
& _9 F9 m* q; e5 U3 j4 k% kA question about EtherChannel compatibility modes. (Choose two.)
! R6 h2 ~& H, A6 Z! w9 pA. passive-passive
B. active-active
C. desirable-desirable
4 n+ f- X4 [7 E* XD. active-passive

E. active-desirable
Correct Answer: CD 我认为答案ACD
Section: part7

考试CCNP交换的朋友，大神，或者网络爱好者，欢迎吐槽、指点。

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5916991

题库很多题都有疑问

alvinyang

我也发现题库中疑问很多，个人觉得如果能找到确切的解析就以解析为准，不然还是以题库为准。参考题库的目的以掌握知识点为主，题库也是网友们的回忆，未必跟真实的考题完全一致。

linchaos

333题应该是BCD