STP Hotspot

I assume this is labeled wrong? STP hotspot maybe?

Yes, thanks for your detection. I updated this page.

I think that in the explanation of question 3:…Fa0/1 on SwitchA and Fa0/2 on SwitchC should be the root ports…(switchC not switchB because Fa0/2 on switchB will be desg FWD )

Yes, thanks for your detection. I updated it!

Ok, thanks for you too!

please specify bridge id or root id ? thks

has this ever come up in the exam?

herp derp

The answer to Question 1 doesn’t look right. From the command “show spanning-tree” on Switch C, interface fa0/2 connects to switch B and has a type of “P2p peer (STP)”

According to Cisco press this means the neighbour (Switch B) is running 802.1D STP

Excerpt:

In addition, this output displays all the active ports participating in the VLAN 171 instance
of RSTP, along with their port types. The string P2p denotes a point-to-point RSTP
port type in which a full-duplex link connects two neighboring switches that both are
running RSTP. If you see P2p Peer(STP), the port is a point-to-point type but the neighboring
device is running traditional 802.1D STP.

I have a query about question 3.
The question is asking about the “port state” of a RSTP topology. I would say that the answer should be “discarding” as RSTP does not have a “blocking” state (doing the basic same thing but since 802.1w, the states and roles changed.
http://www.cisco.com/en/US/tech/tk389/tk621/technologies_white_paper09186a0080094cfa.shtml#topic2

Above comment is about question 4, NOT QUESTION 3!!!

@brightm
@Certprepare

You are right man. I looked it up on my Switch book.

The right aswer is: STP/IEEE 802.1D

@Certprepare
@bdaboy22

You are right man.

RSTP Port Roles:
- Root Port
- Designated Port
- Alternate Port
- Backup Port

RSTP Port States:
- Discarding
- Learning
- Forwarding

The question asks us about the port state, so discarding state is the right answer.

CCNP Switch book, page number 196: RSTP Port Behavior.

hi.. please can any one help me.. i need dumps for 642-813 exam.. if u know plz update..

Actually, the port would be in blocking, not discarding. Remember, from the show output, that switch B is running PVST not RSTP…so it is blocking, not discarding

have you ever tried avast antivirus before?

Actually, its running PVST+, which as i understand it, is RSTP for multiple VLANS. so its discarding

PVRST+ would be discarding; you’re confusing that with PVST+, which converges similar to 802.1D (that’s from Cisco’s documentation). PVST+ still blocks. Lab it up, you’ll see what I mean.

Apologies Peener, i misunderstood the topology.

SwB is running standard STP (or CST, Common spanning tree). its port role will be blocking.
PVST+ is stp that supports both CST and PVST.

confirmed in lab. With RSTP, the port status still shows as BLK, even though technicaly is is discarding, as can be seen for VLAN47 above.

Please correct me if im wrong

Dear All,
I want to comment on Q1. From my point of view the answer should be PVST+ as given.
“In PVST+, one spanning tree instance is created and used for each
active VLAN that is defined on the switch. Each STP instance behaves according to the
traditional 802.1D STP rules.” (ref: 642-813 offical cerfication guide, page 203)
In this question, one instance of STP is used for each active VLAN in the network and that means PVST+ is running on this switch. The point that makes you confused about is each STP instance behaves based on 802.1D STP.

Shortly, PVST+ —> each instance : Traditional 802.1D STP (P2P Peer (STP))
Rapid PVST+ —> each instance: RSTP (P2P)

Switch-C is in RPVST+ mode, the switch begin supporting both RSTP and 802.1D STP neighbors and you can see the neighbor type in the output of the show spanningtree vlan vlan-id command.

Rapid PVST+ : “Spanning tree enabled protocol rstp” (SW-C)

Comment for Q4:
SW-B is in PVST+ mode and each instance is traditional 802.1D STP, so you need to recall five possible states:
■ Disabled
■ Blocking
■ Listening
■ Learning
■ Forwarding

for Rapid PVST+ mode – each instance is RSTP, you need to recall three possible states:
■ Discarding – (This state combines the 802.1D Disabled, Blocking, and Listening states)
■ Learning
■ Forwarding

In this question, obviously after this explanation the answer is “blocking state” due to SW-B is running PVST+, and 802.1D STP for each instance.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

Can anyone explain me the answer for 2nd question MAC addr for switch B please..

Q4,the answer is “blk”.
Because , switchB is running STP, not RSTP.

@mr.xiao
Sorry I don’t get your answer, please explain, thanks.

Also, as per Question 1′s answer, Switch B is running PVST.

Regarding the types in ‘show spanning-tree’ output, found the following reference:

http://www.networkstuff.eu/index.php/Spanning_Tree_Port_Types

Ah ok Switch bt is running STP, but running in PVST flavour since it’s all cisco heh…

Can anyone please tell me if there is sufficient time to answer the questions? Do you have to rush? I’m asking this because at the routing exam i finished having more than one hour left
Thanks

For question #2, it asks Which bridge ID belongs to SW-B?
The explanation should be cleared up to make it easier to understand.

The explanation currently says, “Notice there are two “Cost” value in the picture, the above “Cost” is the total cost from the current switch to the root bridge while the second “Cost” refers to the cost on that interface (Fa0/2). Both these “Cost” are the same so we can deduce that the root bridge is connectly directly to this switch on Fa0/2 interface -> the root bridge is Switch B, and the “Address” field shows its MAC address 000f.34f5.0138. Notice Bridge ID = Bridge Priority + MAC address.”

I think it should read something along the lines of:

_______________________________________________________________
Examine Switch C’s output. Notice their are two “costs” value’s under each VLAN. In each VLAN, both costs are equal (19 and 19) The first cost is the “root path cost” (cumulative cost of all links leading from the current switch to the root bridge). The second cost is the “path cost” (the cost of ONLY the next link in a path) . Whenever a root path cost = the path cost, it is safe to assume the root bridge is directly attached.

Examine the topology and see that SW-C is connected to SW-B from its Fa0/2 interface. Now, revisit the config, and notice that the only VLAN Spanning-Tree that has SW-B’s Fa0/2 status as “root” is in VLAN 47. The root port always points towards the root bridge. Since we’ve already determined that both costs are equal, this means the root bridge is directly connected. When we look at the output for VLAN 47 we see:

Root ID Priority 24623
Address of 000f.34f5.0138.

Remember that Bridge ID = Bridge Priority + MAC address, therefor the Bridge ID of SW-B = 24623+000f.34f5.0138 or 24623.000f.34f5.0138.
____________________________________________________________

It took me quite awhile and lots of looking back at Cisco Press certification guide to figure out exactly how to get to the correct answer on this one, so hopefully this will help others.

!— Type P2p Peer(STP) represents that the neighbor switch runs PVST.

@ping9… I took the bcmsn, and this was on the exam, can’t say for 813

shows a network containing three LAN segments separated by three bridges. shows the result of enabling STP on the bridges in the configuration.

Nice STP cheatsheet

http://devcheatsheet.com/tag/spanning-tree-protocol/

More cheatsheets
http://devcheatsheet.com/search/?q=cisco

@all
anybody got this hotspot?

did anyone get this question in the exam recently?

Protocol networklerde loop a neden olabilecek portlari block duruma alarak calisir.Her hedefe sadece bir yolun aktif olarak calismasini saglar.Spanning-Tree anlatiminda bircok kaynakta switchleri kavram olarak bridge olarak gorebilirsiniz..Sekildeki yapida switchler kendilerine gelen ve hedef adresi bilinmeyen paketleri diger tum portlarindan flood edeceklerdir.Cat 1 ve Cat 2 swtichleri 1 1 portlarina gelen frameleri flood edecek ve ayni frameleri portlarindan alacaklardir portundan aldigi bu frame leri 1 1 portlarindan flood edecek yine diger portlardan alacak bu boyle durmadan devam edecek..Durmadan devam etmekten kasit Switchler in cpu degerleri zamanla artacak ve bir sure sonra hizmet veremeyecek duruma geleceklerdir.Peki neden belirli bir sure sonra durmuyor ?.Bu sorunun cevabi cok acik Ethernet frameleri TTL Time to live alanina sahip degiller. Bu soz stp den konusurken hic unutulmamasi gereken bir soz olmalidir.O halde bunu biraz acmakta yarar var..Broadcast Multicast Unicast ve cok sik duymadigimiz Anycast bu kavramlari bir cogumuz biliyoruz ancak bilmeyen okuyucularimizinda olabilecegini dusunurek bu kavramlari izah edecegim..Broadcast genel anlamiyla yayin yapmak olarak kullanilir..Mesela siz bir topluluga girdiniz ve bir konu hakkinda bagira cagira konusuyorsunuz sizin konustugunuz konuyla hic ilgilenmeyen insanlarda bunu duyuyorlar iste bu broadcasttir..Ayni topluluktasiniz ve yine konustuklarinizi bir cok kisi duyuyor fakat bunlarin hepsi sizin anlattiginiz konuyla ilgiliyse bu durum Multicasttir..Toplulukta sadece tek bir kisiye ozel yalnizca onunla konusuyorsunuz.Bu durumda Unicasttir..Broadcast adresi switchler icin FFFF FFFF FFFF FFFF dir.Switchler broadcast gecirirler ve kendilerine gelen broadcastleri butun portlarina gonderirler…Sekilde Host A nin bir Arp requestte bulundugunu varsayalim Host B ye veri gonderecek ama Mac Adress-Table inda Mac adresi yok bu yuzden arp request gonderiyor.Arp request frameleri broadcast calisirlar.Dolayisiyla bu frame leri alan her 2 switch de bu frame leri butun portlarindan ileteceklerdir.1 numarali portlar ortadaki Hub vasitasiyla birbirlerine bagli yani burada bir yol var ayni zamanda Switch ler bu yapida A diye isimlendirilmis portlardanda bagli yani buradada bir yol var toplam 2 yol var .Switchler 1 portlarindan ve A isimli portlardan broadcastleri yayinlayacaklar ve farkli portlarindan yeniden alacaklar e dongu loop baslayacak.Bu durum Broadcast Storm olarak bilinir..Stp network de bir referans noktasi olusturur ve bu referans noktasindan hareketle eger yukaridaki yapidaki gibi birden fazla yol varsa en iyi yol secimini yapar.Bu referans noktasina Root Bridge denir..Spanning-Tree icerisinde Root Bridge Root Switch sistemi yoneten bridge dir.Butun switchler networke ilk dahil olduklarinda kendilerini root bridge olarak gorurler .Switchler haberlesme icin birbirlerine Bpdu adi verilen paketler gonderirler.Networke ilk dahil olduklarinda da Bpdu Bridge Protocol Data Unit paketi icerisindeki Root Id kismina kendi Bridge id lerini yazarlar..Ortamdaki en kucuk Bridge id ye sahip bridge Root Bridge dir…

This lab was in my exam at 7/April/2011 with 6Q …..only one Q was outside this Hotspot but the rest were from this hotspot as in this site

how I see it

####################################
Question 1:
Which spanning Tree Protocol has been implemented on SW-B?
Answer:
A. STP/IEEE 802.1D
Explanation:
P2p Peer(STP) – If you see P2p Peer(STP), the port is a point-to-point type but the neighboring device is running traditional 802.1D STP
####################################
Question 2:
Which bridge ID belongs to SW-B?
Answer:
A. 24623.000f.34f5.0138
Explanation:
Check ID Priority and MAC on port Fa0/2 towards switch-B. Bridge ID = Bridge Priority + MAC address
####################################
Question 3:
Which port role has interface Fa0/2 of SW-A adopted for VLAN 47?
Answer:
C. Designated port
Explanation:
switch-A is running RSTP. if you see “P2p” – The string P2p denotes a point-to-point RSTP port type in which a full-duplex link connects two neighboring switches that both are running RSTP.
RSTP Port Roles: Root, Designaded, Alternate, Backup
RSTP Port Status: Discarding, Learning, Forwarding
Discarding (This state combines the 802.1D Disabled, Blocking, and Listening states)
Port Fa0/1 on switch-C is Role Altn Status BLK for vlan 47 to prevent loops.
Port Fa0/2 on switch-A is Designated port as port Fa0/1 on this switch-A is root port for vlan 47.
####################################
Question 4:
Which port state is interface Fa0/2 of SW-B in for VLANs 1 and 106?
Answer:
D. Blocking
Explanation:
Switch-B running STP, not RSTP. Port Fa0/2 on switch-C is Designated for vlans 106 and 1.
Switch-A is root for vlans 106 and 1.
Port Fa0/1 on switch-B for vlans 106 and 1 is Root, so port Fa0/2 on this switch has to be BLK to prevent loops.
####################################
Question 5:
Which bridge ID belongs to SW-A?
Answer:
D. 32769.000d.65db.0102
Explanation:
switch-A is root for vlans 106 and 1.
Root ID Priority for vlan 1: 32769
Root ID Priority for vlan 106: 24692
Mac Address for vlans 106 and 1 from switch-A is the same: 000d.65db.0102
Bridge ID = Bridge Priority + MAC address
Options (C. 32768.000d.65db.0102 or D. 32769.000d.65db.0102)
Answer C is not correct.
####################################

hi there,

can you post or recall the 6th question which is not included here?

hello rocket 89

how did you do your hotspot questions. did you get one hotspot or two hotspot questions in your exam.
how did you recognize that this is hotspot question. and after doing your first question did you enter next button or select 2 question option and then 3 and then 4 question. is it just like CCNA vtp hotspot or not.
reply me please early as after three days i am going to take my exam.
guide me properly with tricks and tips.
please .

For Question 1, Spanning-tree Protocol Implemented on SW-B, answer is

A. STP/IEEE 802.1D

Page 204 of CCNP Switch Official Certification Guide:
“The string P2p denotes a point-to-point RSTP port type in which a full-duplex link connects two neighboring switches that both are running RSTP. If you see P2p Peer(STP), the port is a point-to-point type but the neighboring device is running traditional 802.1D STP.”

i thought this question will never appear in our real exam, right? some1 can advice on this?

about question 1,

default Bridge priority is 32768. for STP, BID = BP.MAC-Address
for Per Vlan STP (PVST), BID = (BP+VLAN ID).MAC-Address

notice that, command “spanning-tree vlan root primary” might be issued on SW-B for vlan 47. This will reduce Bridge priority (by two times of 4096). So, now bridge priority for vlan 47 on SW-B becomes 24576. Because this Switch run PVST the overall BID would be (24576+47).000f.34f5.0138 or 24623.000f.34f5.0138

So SW-B running PVST+

hi foo,
Queastion 6:
DSW1 (150-1=149)
DSW2 (200-55=145)
149>145 => DSW1 became active
Answer C is correct
DSW1 (150-6=144)
DSW2 (200-55=145)
144 DSW2 stay active

hi foo,
Queastion 6:
DSW1 (150-1=149)
DSW2 (200-55=145)
149>145 => DSW1 became active
Answer C is correct
DSW1 (150-6=144)
DSW2 (200-55=145)
144<145 DSW2 stay active

@ Pavol

Please state the head of the question as this’s the answer only.Thanks

Q1: I remember this question (or somethings like this)

Switch is raccordin to hub bye LInk A en port A
When the second link B is added betwen switch and hub (all switch port A and b are configured to bpduguard )
switchport A are on err-disable .
one or two switchpor are on err-disable ?
one or two switch port are forwardin ?

what ‘s the answer fo this question ..

Thank’s

The answer for Q1 is PVST check this link: http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

!— Type P2p Peer(STP) represents that the neighbor switch runs PVST.

The answer for Q1 is PVST check this link: http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

!— Type P2p Peer(STP) represents that the neighbor switch runs PVST.

Are the answers to this question correct now.
Thanks for your help

abdeslam…

the bpdu will block a port or and the processor usage will go high

Its definitely PVST+, don’t listen to these other wannabe experts, the bare fact that has different port states for different vlans concludes it must have more than one STP instance, how on earth would this be possible otherwise in one STP instance?

If you’ve got an answer to this question please keep it to yourself or alternatively contact Cisco and they could include your statement as a ‘wrong’ answer.

its very useful

please add mote question………

THX that’s a great awnser!

AFAICT you’ve covered all the bases with this ansewr!

Its definitely PVST+, its running multiple spanning tree + Its on cisco + Its trunking with RPVST.
PVST only supports ISL,

guys, i’ve studied Jeremies videos & preparing for the exam, i need ur advice on which dumps shld i go with. your reply is highly appreciated. – ( I’m Lost ! )
Thanks.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

!— Type P2p Peer(STP) represents that the neighbor switch runs PVST.

Be giuded accordingly

whats the difference btw root ID and bridge ID?

question 2:
i tried it on packet tracer :
the both values cost represented the interface cost …
@certprepare
simply we can deduce the same answer by excluding the others

Hi on question 1 I cant understand wat the clouds are. are those vlans in switch C or are those another switch?

this hotspot is still in the actuall right? or the HSRP hotspot?

Q1 – imho the answer is not right! The true answer is A (STP 802.1D)

From official certification guide: page 204
” In addition, this output displays all the active ports participating in the VLAN 171 instance
of RSTP, along with their port types. The string P2p denotes a point-to-point RSTP
port type in which a full-duplex link connects two neighboring switches that both are
running RSTP. If you see P2p Peer(STP), the port is a point-to-point type but the neighboring
device is running traditional 802.1D STP.”

basta63,
the answer to Q1 would be correct. PVST+ is based on 802.1D STP which is the traditional STP. The difference between PVST+ and 802.1D is that PVST+ runs on several VLANs whereas 802.1D runs on one only.

PVST+ runs 802.1D on several VLANs, so this answer is correct for PVST+ because according to the output shown SW B is running several VLAN (802.1D PVST+) instances not one (802.1D)

@EDG Precisely. I can confirm that Q1 answer is correct. I’ve just tried it with an old switch connected to 3750, traditional STP (802.1D) appears as P2P Peer(STP) on one VLAN only.

!— Type P2p Peer(STP) represents that the neighbor switch runs PVST.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

how can SW B be configured with tr. STP and have multiple vlan instances ??

are this quastion come on exam
?????

firas . Yes.

Dear friends,

I want wright exam (642-813) next week, pls any one send latest dumps,

My id :venkatraj030@gmail.com,

regards,
venkat.

Friends,
I have planned to write my Switching Exam on 3rd December.
Kindly provide me the latest dumps if possible.

MAIL ID: mail2zaheer@gmail.com

Thanks & Regards,
Zaheer Ahmed S

hey zaheer hv u got cleard ur exam?

please tell us about exam questions.
next week m writing exam

hey i want to speak about Q1
answer shud be A
stp

please check and change it

hi everyone,are the dumps change much?i also want to take it,but for me is a little diffcult,any advice is welcome

and my id :laijingli2006@126.com a chinese ccnper.

Hey frnds,

planning to write switch exam in the last week of DEC. will really appreciate if someone can share latest dumps and share some suggestions to my Email:ran4u@inbox.com

Thanks in Advance
RK

This was on the 813 exam as of 12/08/11

An added FYI -

All of the Labs SIMS Listed on CertPrepare are still valid as of 12/08/11. On my test I saw the ….

AAAdot1x
LACP with STP
HSRP Hotspot
VTP2
MLS with EIGRP

ALL OF THESE SIMS/LABS WERE ON MY TEST PEOPLE – KNOW THEM WELL !!!!!!!
(all can be found here on certprepare)

hi on 21st i gave exam i passed it with 934 score.
hey guys earlier i was nervous but when u saw the 1st q in my exam, i smiled.
qs were easy dont need to hesitate.
i had finished my exam within 1 Hr.

for any help regarding dumps or query can contact me at vindude5@gmail.com

ALL tHE Best to all PEOPLE FOR Christmas & 2012.

i didnt get any ques from this part
But it doesnt mean u wont .

There is difference in the answers of vc file and p4s dumps… i m so tens,,, my concepts are so weak…
please tell me on which ones should me prepare????
please reply fast i have exam after 12 hour

Which three statements about STP timers are true? (Choose three.)
A. STP timers values (hello, forward delay, max age) are included in each BPDU.
B. A switch is not concerned about its local configuration of the STP timers values. It will only consider the value of the STP timers contained in the BPDU it is receiving.
C. To successfully exchange BPDUs between two switches, their STP timers value (hello, forward delay, max age) must be the same.
D. If any STP timer value (hello, forward delay, max age) needs to be changed, it should at least be changed on the root bridge and backup root bridge.
E. On a switched network with a small network diameter, the STP hello timer can be tuned to a lower value to decrease the load on the switch CPU.
F. The root bridge passes the timer information in BPDUs to all routers in the Layer 3 configuration.
Answer: ABD

Can some body Explain me the answers

Hi, Great site
Correction to question 1
answer is protocol ieee , which is STP/IEEE 802.1D ?

I have labed this up on 2 x 3560′s as below
Lets use vlan 1

Rack1SW1#sh spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol ieee (SPANNING TREE)
Root ID Priority 32769
Address 001d.e51a.1e80
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 001d.e51a.1e80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300

Interface Role Sts Cost Prio.Nbr Type
——————- —- — ——— ——– ——————————–
Fa0/13 Desg FWD 19 128.15 P2p
Fa0/15 Desg FWD 19 128.17 P2p
Fa0/21 Desg FWD 19 128.23 P2p —-> this port faces Rack1SW4 , so lets check this switch

Rack1SW4#sh spanning-tree vlan 1

VLAN0001
Spanning tree enabled protocol rstp
Root ID Priority 32769
Address 001d.e51a.1e80
Cost 19
Port 17 (FastEthernet0/15)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32769 (priority 32768 sys-id-ext 1)
Address 0025.83f4.7c80
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300

Interface Role Sts Cost Prio.Nbr Type
——————- —- — ——— ——– ——————————–
Fa0/15 Root FWD 19 128.17 P2p Peer(STP) —-These ports are all facing switches running Spanning tree enabled protocol ieee
Fa0/19 Desg FWD 19 128.21 P2p Peer(STP)
Fa0/20 Desg FWD 19 128.22 P2p Peer(STP)

Any other ideas?

Correction….Ive done a bit more digging. It seems that a cisco switch will see a neigbor running in COMPATABLE mode as P2p Peer(STP). This is infact PVST+. So…again we are back with C being corret?

“”Anonymous January 19th, 2012 There is difference in the answers of vc file and p4s dumps… i m so tens,,, my concepts are so weak…”"”

Go back to the books and study hard, you doesnt deserve to be an CCNP!

I would say C is correct based on this link from Cisco’s site.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_example09186a00807b0670.shtml

CONCERNING TEXT FROM LINK BELOW

Access1#show spanning-tree vlan 10

VLAN0010
Spanning tree enabled protocol rstp
Root ID Priority 24586
Address 0015.63f6.b700
Cost 19
Port 107 (FastEthernet3/0/1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec

Bridge ID Priority 32778 (priority 32768 sys-id-ext 10)
Address 000f.f794.3d00
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300

Interface Role Sts Cost Prio.Nbr Type
—————- —- — ——— ——– ——————————–
Fa3/0/1 Root FWD 19 128.107 P2p Peer(STP)
Fa3/0/2 Altn BLK 19 128.108 P2p Peer(STP)

!— Type P2p Peer(STP) represents that the neighbor switch runs PVST.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Based on the Cisco website link above, there is no doubt about Q1 answer. Cisco says,

“Type P2p Peer(STP) represents that the neighbor switch runs PVST”

So case closed!