Follow up questions related to INE Advanced technology work book

Hi Experts,

I wanted to follow up regarding a few  questions that I have after doing INE Advanced technology book:

 

What is the differance between these two entries. One of them indicates that the route islearned locally and the other one indicates directly connected. in one of them, the route is tagged as "C" and the other one is tagged as "L".

R4#show ip route 155.34.0.0

Routing entry for 155.34.0.0/16, 2 known subnets

  Attached (2 connections)

  Variably subnetted with 2 masks

  Redistributing via rip

C        155.34.0.0/24 is directly connected, Tunnel34

L        155.34.0.4/32 is directly connected, Tunnel34

R4#

 

...............................................................................

In INE Advanced Technology LAB , EIGRP AUTO-SUMMARY- what is the reason that the router also installs a static route pointing to Null0? It says "Although All of the routers are advertising the classful summary of their loopback sunet 150.1.0.0/16 to all of their neighbors, each router also installs a local EIGRP summary route to Null0?

It also says that "If one of the router's loopback advertisments was removed, the Null0 summary route would be removed and they would be able to run /16 auto-summary generated by their peers. that is correct. what is the reason that is removed?

What is the reason that Null0 is created when summary route is generated in the router and it is removed when summary route is removed? In that case, when summary-route is generated, static route pointing to Null0 will prevent the ping packet to work and the device will drop the packet.

...........................................................................................

Why ACL for the below question was configured like below? Is this only answer to this question. what are the resources to study more about this type of ACL with odd and even numbers?

 

Configure a one-line access-list on R9 to filter out all routes coming from R7 that have an odd number in the third octet.

 

R9: Access-list 1 permit 0.0.0.0 255.255.254.255  , Router EIGRP 100 , distribute-list 1 in Gigabitethernet1.79

 

......................................................................................................

 

INE Advanced Technology: EIGRP Summarization : what is the reason that we create EIGRP Process-name with "Address-family" like in this example. what is the good resource to study more about it?

 what is the reason that we configured EIGRP Process name in the last part of exercise in R6 when we wanted to apply summarization? what is the usage of the command that we used

 

to apply Summary route under interface? af-interface gigabitethernet1.146 and af-interface gigabitethernet1.67 under "router eigrp multi-af, address-family ipv4 unicast autonomous system 100"?

 

Third Question : in that case, when we wanted to redistribute connected EIGRP Routes, we used it under  under "af-interface"?"

Could you please refer me to the book to read about "EIGRP Process-name with address-family and "topology base"?

 

Thank you for your time in advance.

Comments

  • JoeMJoeM ✭✭✭ ✭✭✭

    Hi Ellie,  You may want to think about splitting these questions up into different threads.  That makes the threads more useful for someone else to search -- knowledgebase of questions.

     

    =================================

    Local is an actual IP Address on that device.   Connected is the subnet.  Notice the subnet mask.

     

    what is the reason that the router also installs a static route pointing to Null0?

    What is the reason that Null0 is created when summary route is generated
    in the router and it is removed when summary route is removed?

    Loop prevention.  Although it is advertising a summary, it will likely not have addresses or routes for everything in that summary.  Traffic going to any unknown addressses will go into a blackhole (aka null0).

    Now if the router has a default route, what would it do with the traffic?   With this safety, it will not send it to the default and start a loop.

     

    Router trick showing the power of wildcard masks.    Good to practice these.

    Yes, is it the only answer. Take a look at the task wording.  Create a ONE-LINE ACCESS-LIST.   The solution is leveraging the impicit deny.    If a two-line was permitted, then we could use reverse logic:  one deny line and then a permit-any line.

    For other resources, maybe go back to the previous curriculum (v4) INE workbook-2.  There were 20 labs and several of them have these type of tasks.

     

     

    ====================

    <BREAK>   Way too many questions bunched together for a single thread.   I did not understand the last slew of questions.  But if you want to do some research -- I think the key search words are  EIGRP NAMED MODE vs CLASSIC MODE.     

    For the lab exam, it is important to understand what is being requested.  Unless you understand the difference between these two modes, they may seem like trick questions.

     

    For the last couple of questions about the location of configs under Named-Mode, it is clear that you need to practice more on the command-line. 

    Practice practice practice.....until it becomes 2nd nature where commands should be applied.  There is also the "?" for help, but in the lab these few seconds will add up.   Learn the command-line for IOS 15.x

  • EllieEllie ✭✭ ✭✭

    Hi Joe,

    Thank you for your answer. It helped a lot. I appreciate everybody's time in INE forum with providing me great guidelines every time that I post any questions.

     

    I am not sure if you meant to send multiple posts with my questions as they are related to different part of INE Advanced technology lab work book.

    As for EIGRP Classic Mode and EIGRP Named Mode, I dont know any books. That was new to me when I came across it in INE lab. It was not in any CCNP books. I also have read TCP IP Volume I with Jeff Doyle and it was not there. would you recommend a book for these advanced EIGRP Topics?

    Also, I have got one more question when I was repeating EIGRP Auto-Summary INE Advanced Technology LAB. When I started from scratch meaning that I did not configure any EIGRP networks and Auto-summary is disabled by default, Just the communications between HUB (R5) and other spokes routers (R1 - R4) were available. I was expecting not to have ping connectivity between Spokes R1 - R4 since I had not applied "No Split-horizon" on R5 Tunnel0 interface. 

    At the begining ping between Spokes was un successsful but after doigng Traceroute, It became available. I am not sure what caused the connectivity to get established. Was it because Traceroute or something else? If that is normal to have Connectivities between Spokes, what is the purpose of having "No Split-horizon" under Tunnel0 Interface on R5. The output is shown below:

    R4#ping 155.1.0.3

    Type escape sequence to abort.

    Sending 5, 100-byte ICMP Echos to 155.1.0.3, timeout is 2 seconds:

    .....

    Success rate is 0 percent (0/5)

    R4#show ip route 155.1.0.3

    Routing entry for 155.1.0.0/24

      Known via "connected", distance 0, metric 0 (connected, via interface)

      Routing Descriptor Blocks:

      * directly connected, via Tunnel0

          Route metric is 0, traffic share count is 1

    R4#traceroute 155.1.0.3

    Type escape sequence to abort.

    Tracing the route to 155.1.0.3

    VRF info: (vrf in name/id, vrf out name/id)

      1 155.1.0.3 3 msec *  2 msec

    R4#

    %PLATFORM-3-ELEMENT_CRITICAL: F0: smand:  RP/0: Committed Memory value 112% exceeds critical level 100%

    R4#show ip route 155.1.0.3

    Routing entry for 155.1.0.0/24

      Known via "connected", distance 0, metric 0 (connected, via interface)

      Routing Descriptor Blocks:

      * directly connected, via Tunnel0

          Route metric is 0, traffic share count is 1

    R4#ping 155.1.0.3

    Type escape sequence to abort.

    Sending 5, 100-byte ICMP Echos to 155.1.0.3, timeout is 2 seconds:

    !!!!!

    Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms

    R4#show ip arp

    Protocol  Address          Age (min)  Hardware Addr   Type   Interface

    Internet  155.1.45.4              -   0050.568d.6bb7  ARPA   GigabitEthernet1.45

    Internet  169.254.100.3           1   0050.568d.7f6a  ARPA   GigabitEthernet1.100

    Internet  169.254.100.4           -   0050.568d.6bb7  ARPA   GigabitEthernet1.100

    Internet  169.254.100.5          65   0050.568d.58cc  ARPA   GigabitEthernet1.100

    R4#

    ..................................


    Then After R4 was able to Ping R3 successfully, R3 started to be able to ping R4 also although it could not at the begining, R3 still is not able to ping any other Spokes routers. The output is below:



    R3#ping 155.1.0.4

    Type escape sequence to abort.

    Sending 5, 100-byte ICMP Echos to 155.1.0.4, timeout is 2 seconds:

    !!!!!

    Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms


    R3#ping 155.1.0.1

    Type escape sequence to abort.

    Sending 5, 100-byte ICMP Echos to 155.1.0.1, timeout is 2 seconds:

    .....

    Success rate is 0 percent (0/5)

    R3#


    .........................................................................................................................................................


    Thank you 

     

     

  • JoeMJoeM ✭✭✭ ✭✭✭

    Hi Ellie, 

    Very happy to help.  Just giving back to the community.

     

    Yes, this is why it is better to separate the topics into different threads.   Follow-up questions will stay on topic much easier.  Separating questions/topics also make it easier for others to search and read, when they have the same question or doubt.   This forum is a knowlegebase of questions and answers.

     

    I do not have time right now to go through your last question here.   Maybe someone on the forum can help with this.   If not, I will try and look at it later this evening.

  • EllieEllie ✭✭ ✭✭

    Thank you very much Joe for your time and everybody's time on this Forum. I truly appreciate it. It is really helpful to use you all expertise in the path to our CCIE journey. other wise, i dont know how I personally could progress in this path after encountering the problems with labs or any technology.

    Regarding my last question related to EIGRP Auto-summary" advanced Technology LAB that I was doing which I tested Tunnel connectivity before configuring any EIGRP Routes, after some furthur testing, I realized that connectivity between Spokes will not work for the first time of Ping, but after second time, it will start working due to ARP Table being created.

    I am not sure about why iit did not work the first time because Spokes are connected to each other through hub, R5. Then the second question is what is the purpose of Disabling Split-horizon on Tunnel interface on HUB router with this config "R5, config t, Tunnel0, No split-horizon". I thought disabling split-horizon will make spokes routers to be pingable but that was not the case and Spokes could ping each other with having split-horizon enabled on tunnel which is sthe default

    I have attached the output below showing that Ping did not work at the begining but started working second time. I initicated the ping from R2 to R4 spokes routers.

    R2#ping 155.1.0.4

    Type escape sequence to abort.

    Sending 5, 100-byte ICMP Echos to 155.1.0.4, timeout is 2 seconds:

    .....

    Success rate is 0 percent (0/5)

    R2#show ip arp

    Protocol  Address          Age (min)  Hardware Addr   Type   Interface

    Internet  169.254.100.1          49   0050.568d.7e0c  ARPA   GigabitEthernet1.100

    Internet  169.254.100.2           -   0050.568d.3d5f  ARPA   GigabitEthernet1.100

    Internet  169.254.100.3          45   0050.568d.7f6a  ARPA   GigabitEthernet1.100

    Internet  169.254.100.4           0   0050.568d.6bb7  ARPA   GigabitEthernet1.100

    Internet  169.254.100.5         132   0050.568d.58cc  ARPA   GigabitEthernet1.100

    R2#ping 155.1.0.4

    Type escape sequence to abort.

    Sending 5, 100-byte ICMP Echos to 155.1.0.4, timeout is 2 seconds:

    !!!!!

    Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms

    R2#

     

Sign In or Register to comment.