Ticket 1

Not sure I read the task correctly, but I can ping to BB1 prefixes using the initial config withcout changing anything.

Yes, r6 redistributes eigrp with metric 15 which poisons the routes advertising to down stream routers but at the same time r6 is learning BB1 prefixes via BGP process and sending them to down stream routers sucessfully.  So, AS 100 can reach BB1 prefixes with no problem.  Comments?

Comments

  • I read the task believing that all routers in AS100 needed to ping those addresses, hence the change for the redistribution.

    First thing I always do with tickets like this is check the router nearest the source to make sure its got the routes and then move a hop away to see if its got the routes.  At the moment I find one hasn't I kick off troubleshooting between the two routers.

  • Yes, r6 redistributes eigrp with metric 15 which poisons the routes advertising to down stream routers but at the same time r6 is learning BB1 prefixes via BGP process and sending them to down stream routers sucessfully.  So, AS 100 can reach BB1 prefixes with no problem.  Comments?

    R6 learns following prefixes from BB1 and redist them into RIP with metric 15
    Rack12R6#sh ip route eigrp
    D    200.0.0.0/24 [90/2297856] via 54.12.1.254, 00:30:37, Serial0/0/0
    D    200.0.1.0/24 [90/2297856] via 54.12.1.254, 00:30:37, Serial0/0/0
    D    200.0.2.0/24 [90/2297856] via 54.12.1.254, 00:30:37, Serial0/0/0
    D    200.0.3.0/24 [90/2297856] via 54.12.1.254, 00:30:37, Serial0/0/0

    SW2 and SW4 learn the prefixes from R6 via RIP:
    Rack12SW2#sh ip route | i 200.0.0.0/24|200.0.1.0/24|200.0.2.0/24|200.0.3.0/24
    R    200.0.0.0/24 [19/15] via 90.12.68.6, 00:00:05, FastEthernet0/6
    R    200.0.1.0/24 [19/15] via 90.12.68.6, 00:00:05, FastEthernet0/6
    R    200.0.2.0/24 [19/15] via 90.12.68.6, 00:00:05, FastEthernet0/6
    R    200.0.3.0/24 [19/15] via 90.12.68.6, 00:00:05, FastEthernet0/6

    But not R2 and R4:
    Rack12R4#sh ip route | i 200.0.0.0/24|200.0.1.0/24|200.0.2.0/24|200.0.3.0/24

    They also don't learn it via BGP:
    Rack12R4#sh ip bgp 200.0.0.0
    % Network not in table
    Rack12R4#sh ip bgp 200.0.1.0
    % Network not in table

    After fixing "redist eigrp 10 metric 15" on R6, R2 and R4 learn the prefixes:
    Rack12R4#sh ip route | i 200.0.0.0/24|200.0.1.0/24|200.0.2.0/24|200.0.3.0/24
    R    200.0.0.0/24 [120/15] via 90.12.104.10, 00:00:04, FastEthernet0/1
    R    200.0.1.0/24 [120/15] via 90.12.104.10, 00:00:04, FastEthernet0/1
    R    200.0.2.0/24 [120/15] via 90.12.104.10, 00:00:04, FastEthernet0/1
    R    200.0.3.0/24 [120/15] via 90.12.104.10, 00:00:04, FastEthernet0/1

  • I agree, I had the same observation....thus if R6 advertises urther it will add additional hopcount to rip metric thus other devices downstream will neglect the prefixes into the RIB...

     

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