OPERATIONAL DEFECT DATABASE
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BGP points that traffic should be forwarded over backup path instead of primary path. For example: RP/0/RP1/CPU0:ASR9K-1#show bgp vrf abcd 10.0.0.6/31 BGP routing table entry for 10.0.0.6/31, Route Distinguisher: 65000:123 Versions: Process bRIB/RIB SendTblVer Speaker 12577206 12577206 Local Label: 32313 -----------------------------------------> local label assigned by BGP Last Modified: Nov 31 01:00:00.000 for 12:00:00 Paths: (4 available, best #1) Advertised to PE update-groups (with more than one peer): 0.1 Path #1: Received by speaker 0 Advertised to PE update-groups (with more than one peer): 0.1 Local 172.16.1.3 from 0.0.0.0 (10.10.10.28) Origin incomplete, metric 11, localpref 100, weight 32768, valid, redistributed, best, group-best, import-candidate -----------------------> best path should be unlabelled Received Path ID 1, Local Path ID 1, version 12577206 Extended community: OSPF route-type:0:1:0x0 OSPF router-id:10.10.10.28 RT:65000:789 RT:65000:456 Path #2: Received by speaker 0 Not advertised to any peer Local 10.10.10.27 (metric 201) from 10.10.10.7 (10.10.10.27) Received Label 42915 Origin incomplete, metric 0, localpref 100, valid, internal, backup, add-path, import-candidate, imported Received Path ID 1, Local Path ID 2, version 12577206 Community: 65000:65000 Extended community: OSPF route-type:0:1:0x0 OSPF router-id:0.0.0.0 RT:65000:789 RT:65000:456 Originator: 10.10.10.27, Cluster list: 10.10.10.7 Source AFI: VPNv4 Unicast, Source VRF: itdc, Source Route Distinguisher: 65000:123 Path #3: Received by speaker 0 Not advertised to any peer Local 10.10.10.27 (metric 201) from 10.10.10.8 (10.10.10.27) Received Label 42915 ---------> this is label received for backup path Origin incomplete, metric 0, localpref 100, valid, internal, import-candidate, imported Received Path ID 1, Local Path ID 0, version 0 Community: 65000:65000 Extended community: OSPF route-type:0:1:0x0 OSPF router-id:0.0.0.0 RT:65000:789 RT:65000:456 Originator: 10.10.10.27, Cluster list: 10.10.10.8 Source AFI: VPNv4 Unicast, Source VRF: itdc, Source Route Distinguisher: 65000:123 Path #4: Received by speaker 0 Not advertised to any peer Local 10.10.10.27 (metric 201) from 10.10.10.9 (10.10.10.27) Received Label 42915 Origin incomplete, metric 0, localpref 100, valid, internal, import-candidate, imported Received Path ID 1, Local Path ID 0, version 0 Community: 65000:65000 Extended community: OSPF route-type:0:1:0x0 OSPF router-id:0.0.0.0 RT:65000:789 RT:65000:456 Originator: 10.10.10.27, Cluster list: 10.10.10.9 Source AFI: VPNv4 Unicast, Source VRF: itdc, Source Route Distinguisher: 65000:123 RP/0/RP1/CPU0:ASR9K-1#show mpls forwarding labels 32313 ---> traffic is forwarded over backup path. Local Outgoing Prefix Outgoing Next Hop Bytes Label Label or ID Interface Switched ------ ----------- ------------------ ------------ --------------- ------------ 32313 42915 65000:123:10.0.0.6/31 \ 10.10.10.27 0
BGP PIC. CE dual-homed to 2 PE(s) Same RD is configured on the VRFs of the dual-homed PE(s) Primary path (CE-PE) is redistributed via OSPF/IGP on both PE(s) Primary path (CE-PE) is down on PE and triggers label retention on PE (traffic over backup path) New prefixes are learnt after primary path (CE-PE) is down
Clear bgp version for the prefix (e.g.): RP/0/0/CPU0:PE1#clear bgp version vpnv4 unicast rd 65000:123 10.0.0.6/31
Issue is really rare to happen and has only been reported on a heavy churn of routes over IGP in use (OSPF on example above).
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