Home > Distribute List

Distribute List

July 26th, 2019 in ROUTE 300-101 Go to comments

Question 1

Question 2

Explanation

A distribute list is used to filter routing updates either coming to or leaving from our router. In this case, the “out” keyword specifies we want to filter traffic leaving from our router. Access-list 2 indicates only routing update for network 1.2.3.0/24 is allowed (notice that every access-list always has an implicit “deny all” at the end).

Question 3

Explanation

To prevent routing updates through a specified interface, use the passive-interface type number command in router configuration mode.

Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_pi/configuration/xe-3s/iri-xe-3s-book/iri-default-passive-interface.html

Comments
  1. CCNP student
    February 28th, 2017

    Hello everyone, someone knows why the sim in the exam 300-101, do not accept the command ( copy running-config startup-config), is this command necessary. ? only accept this command in the SIM OSPF stub. when I put the command, showed me this ” Command is not implemented”

  2. Guacca
    August 11th, 2017

    Are we certain Q3 is correct?

    Per Cisco the passive-interface command – “With most routing protocols, the passive-interface command restricts outgoing advertisements only”

    It does not stop incoming routing updates, only outgoing.

    https://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/13675-16.html

  3. Guacca
    August 11th, 2017

    Q3 – please update answer to C

    per cisco – “Using the passive interface command can prevent routers from sending routing updates through a router interface.”

    https://www.cisco.com/c/en/us/support/docs/ip/interior-gateway-routing-protocol-igrp/9105-34.html

  4. anu
    August 18th, 2017

    @ Guacca
    yeah Q3 should be option c

  5. Correction
    September 23rd, 2017

    Question 3

    Which command prevents routers from sending routing updates through a router interface?
    A. default-metric 0
    B. distribute-list in
    C. passive-interface
    D. distribute-list out

    C is the correct answer.

  6. learner
    October 15th, 2017

    I believe

    Question 3 – correct answer should be C. passive-interface
    Which command prevents routers from sending routing updates through a router interface?

    A. default-metric 0
    B. distribute-list in
    C. passive-interface
    D. distribute-list out

    Question is saying “Which command PREVENTS…”

    “Preventing Routing Updates Through an Interface”

    Using the passive interface command can prevent routers from sending routing updates through a router interface. Keeping routing update messages from being sent through a router interface prevents other systems on that network from learning about routes dynamically. For examples using the passive interface command, see the “Passive Interface Examples” section in Configuring IP Routing Protocol-Independent Features.

    For RIP and IGRP, the passive interface command stops the router from sending updates to a particular neighbor, but the router continues to listen and use routing updates from that neighbor; however, on EIGRP, the passive interface command affects the protocol differently, as explained in How Does the Passive Interface Feature Work in EIGRP?

    “Controlling the Processing and Advertising of Routes in Routing Updates”

    To control the advertising and processing of routes in routing updates, use the distribute-list command. There are two distribute-list commands: distribute-list in and distribute-list out. They are similar in syntax, but the options available to each and their behavior are very different.

    The distribute-list in command is used to control which routes are processed in incoming routing updates. See the Using distribute-list in section for an example of this command.

    The distribute-list out command is used to control which routes are included in outgoing routing updates. See the Using distribute-list out section for an example.

    https://www.cisco.com/c/en/us/support/docs/ip/interior-gateway-routing-protocol-igrp/9105-34.html

  7. Paco
    October 31st, 2017

    Q3. Correct answer is C

  8. Night King
    November 8th, 2017

    Q3. is definitely answer ‘C’, passive-interface. distribute-list does not inherently block outgoing updates. the key thing about distribute-list is to FILTER updates to your liking, which would likely include permitting some routes through. With everyone calling this out, why isn’t PDF updated?

  9. Barrett
    November 9th, 2017

    Dose anyone have the full version for this dumps? https://drive.google.com/open?id=0B5mAFqgydmCzVWtzU09fYV9SZGc

  10. digitaltut
    March 21st, 2018

    @all: Yes, the correct answer for Q.3 should be C. Thanks for your information, we fixed it.

  11. khaled
    April 28th, 2018

    Can anyone give an explaination about distributed list

  12. Dane
    June 22nd, 2018

    Scored 9xx, used dumps from IT-Libraries. You can find them on the net for free or in the comments here.

  13. renan
    July 20th, 2018

    @dane can you share your dumps?

  14. M2
    August 2nd, 2018

    Hi Digitut,

    update the same things in the Composite Quizzes, as the Composite Quizzes show the answer as distribute-list out.

    Question 3

    Which command prevents routers from sending routing updates through a router interface?

    A. default-metric 0
    B. distribute-list in
    C. passive-interface
    D. distribute-list out

    Answer: C

  15. Tedy
    August 6th, 2018

    9TUT
    Please corect Question 23 Composite Quizz 15
    showing B. distribute-list out
    The corect answer is C. passive-interface

  16. Bb
    November 10th, 2018

    Good

  17. Sorlags
    November 12th, 2018

    Update @M2 info

    Question 3

    Which command prevents routers from sending routing updates through a router interface?
    A. default-metric 0
    B. distribute-list in
    C. passive-interface
    D. distribute-list out

    Answer is C. But in Composite Quizzes 1 it’s D.

  18. Dany1
    November 19th, 2018

    Question 1. Answer E is ok, but is very stupid
    “E. Router B will not advertise the 10.0.0.0/8 network because it is blocked by the ACL”
    First of all, 10.0.0.0/8 is directly connected interface of Router A.So, Router A will send network “10.0.08/8” through EIGRP routing updates.
    But, router B interface which connect to ROuter A is also EIGRP enabled interface (let’s suppose A f0/0 is connected to Bf0/0. On B, enable eigrp on f0/0 and that means, by default, split-horison ENABLED and route learned from that interface will not be advertise back.. That means no way, ROuter B will send back 10.0.0.0/8.
    On the other hand, i agree theoretical, 10.0.0/8 is not written in access-list, but even without distribute-list, B will never advertise 10.0.0.0/8 to Router A.

  19. Sorlags
    February 3rd, 2019

    In NUQ – Part 5 we find a question (Q13) like the Distributed list Q3

    Refer to the exhibit.

    access-list 1 permit 10.1.1.0 0.0.0.255
    access-list 1 deny any

    Which command we use to control the type of routes that are processed in incoming route updates?

    A. passive-interface
    B. distribute-list 1 out
    C. distribute-list 1 in
    D. ip vrf forwarding

    Answer is C

    the difference with Q3 is that there is an access-list. If there is not this ACL the answer is “passive-interface”.

  20. suntzu
    July 20th, 2019

    Question 3

    Which command prevents routers from sending routing updates through a router interface?
    A. default-metric 0
    B. distribute-list in
    C. passive-interface
    D. distribute-list out

    Answer is D. These questions are talking about the freaking distribution list/access list. The topic if the questions are distribution lists that go along with ACCESS LIST. You guys are not reading completely through the information. You are grabbing the first piece of info and running with it. @ Sorlags with the last post is correct. I see Sorlags corrected his post from over a year ago where he said passive-interface was correct but it wasn’t.

    Please continue to read deeper with the post below from the cisco book…concerns EIGRP and passive interface usage.
    https://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/13675-16.html#passive

    When the passive-interface command is used in EIGRP, the router cannot form neighbor adjacencies on the interface, or send or receive routing updates. But, if you want the outgoing routing updates alone to be suppressed but the inbound updates continue to be received (and the routers still continue to be neighbors), then use the distribute-list command:

    R1(config)#access-list 20 deny any

    R1(config)#router eigrp 1
    R1(config-router)#no passive-interface serial 0
    R1(config-router)#distribute-list 20 out serial 0 (obviously if you want incoming updates ALONG to be suppressed, you change it to IN)

    ….i.e. The question asks about controlling processed incoming route updates. The question does not ask “how to kill neighbors completely”. If you use the passive interface command on eigrp it stops EVERYTHING not just updates.

    plus i took the damn test and scored nearly perfect on it. I missed maybe 4 questions total

  21. suntzu
    July 20th, 2019

    R1(config)#access-list 20 deny any

    R1(config)#router eigrp 1
    R1(config-router)#no passive-interface serial 0
    R1(config-router)#distribute-list 20 out serial 0 (obviously if you want incoming updates ALONE to be suppressed, you change it to IN)

    Misspelled alone by mistake…doesn’t matter though. Answer is still the same damn thing i posted.

  22. suntzu
    July 20th, 2019

    My bad, I see that @Sorlags still didn’t completely understand that they are talking about distribution lists, which are extensions of access list. This topic isn’t even talking about passive interface anywhere on this page period.

    Again, read what I posted above. passive interface causes issues with EIGRP. The question doesn’t ask about all protocols except EIGRP. We are to assume they are talking about every protocol and passive interface causes issues with EIGRP. This is why using a distribution list is the answer.

  23. SNBOY
    November 10th, 2019

    I would like to see an explanition from Q1. Why answer A is not correct?

  24. Anonymous
    January 8th, 2020

    @SNBOY – traffic will not be blocked , its routing updates . Also the ACL explicitly permits 172.x.x.x network .

  25. nik
    March 15th, 2020

    whats is time based ACL

  26. Sonakshi
    September 3rd, 2020

    Time-based ACLs are types of control lists that allow for network access based on time or day. Its function is similar to that of the extended ACLs. Time-based ACLs is implemented by creating a time range that defines specific times of the day and week. … The time range relies on the router system clock.

  1. No trackbacks yet.