[j-nsp] Incorrect next hop taken ?

[joe mcguckin]

Can someone please explain this?

joe at gw.pao> show route 63.223.0.0/24 detail

inet.0: 128857 destinations, 210034 routes (128853 active, 1 holddown, 4
hidden)
63.223.0.0/24 (3 entries, 1 announced)
        *BGP    Preference: 170/-301
                Source: 209.81.63.34
                Next hop: 209.81.1.1 via ge-0/1/0.41, selected
                Protocol next hop: 206.223.115.47 Indirect next hop: 85e3b90
308
                State: <Active Int Ext>
                Local AS:  7091 Peer AS:  7091
                Age: 3w5d 19:05:20      Metric: 100     Metric2: 0
                Task: BGP_7091.209.81.63.34+51128
                Announcement bits (3): 0-KRT 3-BGP.0.0.0.0+179 4-Resolve
inet.0 
                AS path: 19151 I
                Communities: 7091:390
                Localpref: 300
                Router ID: 209.81.63.34
         BGP    Preference: 170/-301
                Source: 216.200.254.177
                Next hop: 216.200.254.177 via ge-0/1/0.44, selected
                State: <Ext>
                Inactive reason: AS path
                Local AS:  7091 Peer AS:  6461
                Age: 5:58:36    Metric: 100
                Task: BGP_6461.216.200.254.177+179
                AS path: 6461 19151 I
                Communities: 7091:390
                Localpref: 300
                Router ID: 209.249.254.19
         BGP    Preference: 170/-101
                Source: 209.81.1.1
                Next hop: 209.81.1.1 via ge-0/1/0.41, selected
                State: <Ext>
                Inactive reason: Local Preference
                Local AS:  7091 Peer AS:  6939
                Age: 3w5d 12:37:20
                Task: BGP_6939.209.81.1.1+179
                AS path: 6939 19151 I
                Communities: 7091:380
                Localpref: 100
                Router ID: 216.218.252.145



Ok - this would seem to indicate the correct next hop is the ibgp hop.

Now, watch the traceroute...


joe at gw.pao> traceroute as-number-lookup 63.223.0.01
traceroute to 63.223.0.01 (63.223.0.1), 30 hops max, 40 byte packets
 1  gige-g0-0-7.gsr12008.pao.he.net (64.62.200.185) [AS  6939]  1.031 ms
1.073 ms  0.939 ms
 2  gige-g1-0.gsr12012.pao.he.net (216.218.254.34) [AS  6939]  9.387 ms
0.848 ms  1.331 ms
 3  pos7-0.gsr12012.sjc2.he.net (66.220.13.41) [AS  6939]  1.683 ms  1.899
ms  1.356 ms
 4  br-1.sjc.webusenet.com (206.223.116.18) [AS  6461]  77.148 ms  76.220 ms
76.243 ms
 5  ge1-25-5-sjc-b0-00.bb.ibis7.net (63.223.1.146) [AS  19151]  77.057 ms
77.078 ms  77.164 ms
 6  oc48-1-37-1-atl-b0-00.bb.ibis7.net (63.223.1.17) [AS  19151]  77.350 ms
77.042 ms  77.235 ms
 7  unknown63223001105.ibis7.net (63.223.1.105) [AS  19151]  76.365 ms
76.685 ms  76.342 ms
 8  amm-b1-02.bb.ibis7.net (63.223.0.1) [AS  19151]  76.489 ms  77.155 ms
77.010 ms


It's taking the wrong next hop!


joe