Mock Lab 6 - Help!



well, I did pretty good at labs 3,4,5 but just got smacked down by this one. My lab is in a few days. Could you help me to understand the following:


exo 4.11: It says to throw a warning when we reach X routes redistributed FROm RIP into OSPF on R5. We redistribute BOTH RIP and EIGRP in ospf 1 on R5.

The guide says to configure "redistribute maximum-prefix" under ospf 1. I believe this is wrong as it will count BOTH RIP adn EIGRP routes.

What I did is to configure a second "blank" ospf process where I was redistributing only RIP and put the redistribute "maximun-prefix" only there.


5.3 Switch QoS: I totally missed this one, that is the one I am the more keen the get an explanation:

1. - The explanation was 
"class-default is useless with MLS on Catalyst 3550, could you clarify?

2. - There is no global command "mls qos" configured on the solution, is this correct?

3. - Why is "mls qos trust dscp" configured on all the L2 ports in the solution?


edit: I think I found out:

1. I applied the policy-map to the SVI. This should have been done on ALL the L2 ports belonging to the VLAN (fa0/24 here)

2. "mls qos" MUST be configured, it was either in initial configs or is missing for the solution

3. due to mls qos, all dscp are now rewritten to "0", this behavior needs to be overriden by configuring "mls qos trust dscp" on ALL the ports.




11.1 BGP Peerings. The task more or less asks to build a GRE tunnel between SW1 adn R6 and pass all the traffic through it.

However, it is my understanding that 3550/3560 does not support tunnel termination? How to complete this task?


11.2 Very interesting one ;)



Thanks in advance!












  • Don't know about the others but you can setup tunnels on 3550/3560 :



    interface Tunnel10

     ip address

     tunnel source Loopback0

     tunnel destination



    RSRack23SW3#sh ver

    Cisco IOS Software, C3550 Software (C3550-IPSERVICESK9-M), Version 12.2(44)SE, RELEASE SOFTWARE (fc1)



    Type escape sequence to abort.

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


    Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms



    Also you're right about having to configure (i.e. turn on) qos using the global mls qos command, and it's effect on interfaces trust of incoming packets. By default, this is turned off, but once you enable QoS all frames have their COS overwritten to 0 (which will then have the affect of changing the DSCP to default also due to the mutation map)..





  • Dan, thanks for your swift help.

    I tested the tunnel on 3550 and it indeed works fine, don't why I had in mind it was not supported.



    Anyway, I just received my number this night!






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