U.u.u. ????????????

Tommy2727Tommy2727 MemberMember Posts: 48 ■■□□□□□□□□
in CCNP
Cheers all hope all is well, can some one assist me on the concepts of the U.U.U's ... Did the packets get to it's destination or floating in limbo???


I have two AS's 6500 5500 running BGP, the 5500 as has 4 routers all running ospf for internal routing, two transit router only running ospf and two bgp routers running ibgp. They are peered with one another using loopback IP addresses, the 6500ASas has 1 router only running bgp and is peered with one of the 5500 bgp routers r4.... the external AS 6500 is advertising multiple networks in AS5500 routers say r1 & r4 . R1 & R4 are in the same as5500 running ibgp (not meshed, not directly connected using loop backs as neighbors but is exchanging routes) transiting through two routers only running ospf.

r4 router is peered up with (as6500 router r5) and the r4 router has all the advertised r5 routes........... all is well. (working)

I have another bgp router running on the other end of the AS5500 named r1 with a lot of networks connected running OSPF internally

the two BGP routers in the AS5500 are IBGP peers. The (as6500) routes are in the bgp table and the routing table of r1, however, when im on r1 trying to ping them external bgp routes AS6500 that i see in my routing table as valid im getting
u.u.u


SIGH.............



Success rate is 0 percent (0/5)

can anyone help

thanks
Practice, Practice, and more Practice make Perfection.....
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Comments

  • SteveO86SteveO86 Senior Member Member Posts: 1,423
    Your getting ICMP unreachables back, should be a routing issue somewhere. Might want to post the configs.

    I believe unreachables are rate-limited by default which is why you get one unreachable, one timeout (rinse and repeat) leading the U.U.U pattern
    My Networking blog
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  • networker050184networker050184 Went to the dark side.... Mod Posts: 11,962 Mod
    I believe you are running into a very common mistake for beginner BGPers. A couple things to look at.

    Next hop reachable?
    Is the source of the pings reachable?
    An expert is a man who has made all the mistakes which can be made.
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  • Tommy2727Tommy2727 Member Member Posts: 48 ■■□□□□□□□□
    Yes next hop is reachable, the puzzling thing is I'm seeing the routes in my routing table... If any confg was wrong in the AS's i wouldn't see the routes in the routing table...
    Practice, Practice, and more Practice make Perfection.....
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  • Tommy2727Tommy2727 Member Member Posts: 48 ■■□□□□□□□□
    Router#sh ip bgp
    BGP table version is 9, local router ID is 1.1.1.1
    Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
    r RIB-failure, S Stale
    Origin codes: i - IGP, e - EGP, ? - incomplete

    Network Next Hop Metric LocPrf Weight Path
    *> 2.2.2.0/24 0.0.0.0 0 32768 i
    *>i50.1.1.0/24 4.4.4.4 0 100 0 6500 i
    *>i200.1.1.0 4.4.4.4 0 100 0 6500 i
    *>i200.1.2.0 4.4.4.4 0 100 0 6500 i
    *>i200.1.3.0 4.4.4.4 0 100 0 6500 i
    *>i200.1.4.0 4.4.4.4 0 100 0 6500 i
    *>i200.1.5.0 4.4.4.4 0 100 0 6500 i
    *>i200.1.6.0 4.4.4.4 0 100 0 6500 i
    Router#sh ip rou
    Router#sh ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2
    i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
    ia - IS-IS inter area, * - candidate default, U - per-user static route
    o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

    B 200.1.4.0/24 [200/0] via 4.4.4.4, 03:20:31
    1.0.0.0/32 is subnetted, 1 subnets
    C 1.1.1.1 is directly connected, Loopback1
    50.0.0.0/24 is subnetted, 1 subnets
    B 50.1.1.0 [200/0] via 4.4.4.4, 03:20:31
    B 200.1.5.0/24 [200/0] via 4.4.4.4, 03:20:31
    2.0.0.0/24 is subnetted, 1 subnets
    C 2.2.2.0 is directly connected, Loopback2
    B 200.1.6.0/24 [200/0] via 4.4.4.4, 03:20:31
    4.0.0.0/32 is subnetted, 1 subnets
    O 4.4.4.4 [110/129] via 10.1.13.2, 03:50:14, Serial0/0
    [110/129] via 10.1.12.2, 03:50:15, Serial0/1
    B 200.1.1.0/24 [200/0] via 4.4.4.4, 03:20:33
    B 200.1.2.0/24 [200/0] via 4.4.4.4, 03:20:34
    B 200.1.3.0/24 [200/0] via 4.4.4.4, 03:20:34
    10.0.0.0/24 is subnetted, 4 subnets
    C 10.1.13.0 is directly connected, Serial0/0
    C 10.1.12.0 is directly connected, Serial0/1
    O 10.1.24.0 [110/128] via 10.1.12.2, 03:50:16, Serial0/1
    O 10.1.34.0 [110/128] via 10.1.13.2, 03:50:16, Serial0/0
    Router#ping 200.1.2.1

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 200.1.2.1, timeout is 2 seconds:
    U.U.U
    Success rate is 0 percent (0/5)
    Router#ping 200.1.3.1

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 200.1.3.1, timeout is 2 seconds:
    U.U.U
    Success rate is 0 percent (0/5)
    Practice, Practice, and more Practice make Perfection.....
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  • SteveO86SteveO86 Senior Member Member Posts: 1,423
    Does the other side have a route back?
    My Networking blog
    Latest blog post: Let's review EIGRP Named Mode
    Currently Studying: CCNP: Wireless - IUWMS
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  • Tommy2727Tommy2727 Member Member Posts: 48 ■■□□□□□□□□
    SteveO86 wrote: »
    Does the other side have a route back?

    No I was thinking the same ,,, should I add a default or static route all the way through to that side, then again the routes are in the table on the that side, is it the way Im advertising these routes, im using the network command..


    R5#sh ip bgp
    BGP table version is 21, local router ID is 200.1.6.1
    Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
    r RIB-failure, S Stale
    Origin codes: i - IGP, e - EGP, ? - incomplete

    Network Next Hop Metric LocPrf Weight Path
    *> 2.2.2.0/24 10.1.45.1 0 5500 i
    *> 50.1.1.0/24 0.0.0.0 0 32768 i
    *> 200.1.1.0 0.0.0.0 0 32768 i
    *> 200.1.2.0 0.0.0.0 0 32768 i
    *> 200.1.3.0 0.0.0.0 0 32768 i
    *> 200.1.4.0 0.0.0.0 0 32768 i
    *> 200.1.5.0 0.0.0.0 0 32768 i
    *> 200.1.6.0 0.0.0.0 0 32768 i
    R5#sh ip rou
    R5#sh ip route
    Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2
    i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
    ia - IS-IS inter area, * - candidate default, U - per-user static route
    o - ODR, P - periodic downloaded static route

    Gateway of last resort is not set

    C 200.1.4.0/24 is directly connected, Loopback3
    50.0.0.0/24 is subnetted, 1 subnets
    C 50.1.1.0 is directly connected, Loopback6
    C 200.1.5.0/24 is directly connected, Loopback4
    2.0.0.0/24 is subnetted, 1 subnets
    B 2.2.2.0 [20/0] via 10.1.45.1, 04:39:16
    C 200.1.6.0/24 is directly connected, Loopback5
    C 200.1.1.0/24 is directly connected, Loopback0
    C 200.1.2.0/24 is directly connected, Loopback1
    C 200.1.3.0/24 is directly connected, Loopback2
    10.0.0.0/24 is subnetted, 1 subnets
    C 10.1.45.0 is directly connected, Serial0/0
    R5#ping 2.2.2.2

    Type escape sequence to abort.
    Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
    .....
    Success rate is 0 percent (0/5)
    Practice, Practice, and more Practice make Perfection.....
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  • inscom.brigadeinscom.brigade I like soup Member Posts: 400 ■■■□□□□□□□
    Networker050184 is this limited to BGP, or could it also be associated to distance vector?

    I saw this last evening when I did a ping. u.u.u.u.u.
    I thought I was just tired and dropped my forhead to the desk. I am not running BGP, but have ripv2 running.
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  • networker050184networker050184 Went to the dark side.... Mod Posts: 11,962 Mod
    The issue is simple routing, but it's something a lot of people seem to miss with BGP due to the lack of end to end IGP connectivity.
    An expert is a man who has made all the mistakes which can be made.
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