Cannot ping a redistributed route

I have redistributed a route from eigrp running on R3, R5 to ospf. This ospf process is running on R1,R2,R3.



The route is installed in R1 quite alright but I don't know why I cannot ping this route from R1.



As shown below, I have no problem pinging this route on R3 even though the route came from R5 but both R3 & R5 are eigrp neighbors.



See the info below



RSRack1R1#sh ip ro 192.10.1.5
Routing entry for 192.10.1.0/24
Known via "ospf 1", distance 110, metric 20, type extern 2, forward metric 64
Last update from 132.1.0.2 on Serial1/0, 00:08:41 ago
Routing Descriptor Blocks:
* 132.1.0.2, from 150.1.2.2, 00:08:41 ago, via Serial1/0
Route metric is 20, traffic share count is 1

RSRack1R1#ping 192.10.1.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.10.1.5, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)


Pinging work on this route from R3:


Rack1R3#sh ip ro 192.10.1.5
Routing entry for 192.10.1.0/24
Known via "eigrp 10", distance 170, metric 2195456, type external
Redistributing via eigrp 10, ospf 1
Advertised by ospf 1 metric 30 subnets
Last update from 132.1.35.5 on Serial1/1.1, 00:26:33 ago
Routing Descriptor Blocks:
* 132.1.35.5, from 132.1.35.5, 00:26:33 ago, via Serial1/1.1
Route metric is 2195456, traffic share count is 1
Total delay is 21000 microseconds, minimum bandwidth is 1544 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 1/255, Hops 1


Rack1R3#ping 192.10.1.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.10.1.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/44/56 ms

Comments

  • What does traceroute say? If there is a routing loop, traceroute will keep repeating through the same IP addresses.

    Darrell
  • Darell,

    This is what I got back from tracerouter

    Rack1R3#traceroute 192.10.1.5

    Type escape sequence to abort
    Tracing the route to 192.10.1.5

    1 132.1.0.2 24 msec 52 msec 44 msec
    2 132.1.23.3 64 msec 92 msec 68 msec
    3 * * *
    4 * * *
    5 * * *
    6 * * *
    7 * * *

    ...... until it stops....
  • Additional Info:

    The redistribution path looks like this;
    R1 ----- R2 ------- R3 ------ R5

    - R2 & R3 are eigrp neigbors , Likewise R3 & R5 are eigrp neigbors too

    - R1, R2 & R3 are ospf neigbors



    This route is a connected route on R5 as shown below and as expected it's pingable



    Gateway of last resort is not set

    54.0.0.0/24 is subnetted, 1 subnets
    D 54.1.2.0 [90/3196416] via 132.1.35.3, 15:51:45, Serial1/0.1
    132.1.0.0/24 is subnetted, 4 subnets
    C 132.1.5.0 is directly connected, Ethernet0/0
    D 132.1.23.0 [90/2681856] via 132.1.35.3, 15:51:53, Serial1/0.1
    D 132.1.26.0 [90/2684416] via 132.1.35.3, 15:51:45, Serial1/0.1
    C 132.1.35.0 is directly connected, Serial1/0.1
    C 192.10.1.0/24 is directly connected, Ethernet0/1
    150.1.0.0/24 is subnetted, 3 subnets
    C 150.1.5.0 is directly connected, Loopback0
    D 150.1.3.0 [90/2297856] via 132.1.35.3, 16:43:54, Serial1/0.1
    D 150.1.2.0 [90/2809856] via 132.1.35.3, 15:51:45, Serial1/0.1
    Rack1R5#ping 192.10.1.5

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 192.10.1.5, timeout is 2 seconds:
    !!!!!
    Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/8 ms




    If this packet gets to R5 from R1, R5 has a route back as shown from traceroute from R3 to R5. Even from R2 that is 2 hop away from R5 !



    But NOTE that the route was redistributed into EIGRP in R5, hence it appears as D EX routes on both R2 & R3.



    Rack1R3#traceroute 192.10.1.5

    Type escape sequence to abort.
    Tracing the route to 192.10.1.5

    1 132.1.35.5 40 msec * 64 msec
    Rack1R3#


    Rack1R2#traceroute 192.10.1.5

    Type escape sequence to abort.
    Tracing the route to 192.10.1.5

    1 132.1.23.3 24 msec 40 msec 40 msec
    2 132.1.35.5 116 msec * 92 msec
    Rack1R2#
  • I have figured this out !!!

    I had to start "thinking" as a router to figure out what was wrong here......

    First I narrowed the problem down to communication down to R3 as shown by traceroute, the routes hits R3 serial intf. so why is R3 not routing it towards R5 or routing the icmp backk to R1.

    Finally I found out that I FORGOT to redistribute ospf into eigrp on R3, hence R5 does not really have the ip address of R1 in its routing table, hence when it receives packets from R1, it drops it!!

    Thanks Mohan for commenting.
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