5/20/2021

"Pending BGP Convergence" and invalid on MPLS/SR/EVPN BGP RR

On a BGP EVPN RR, I am seeing some EVPN routes are marked as "Pending BGP Convergence" as below:

RR1.12:01:04#sh bgp evpn
BGP routing table information for VRF default
Router identifier 100.250.250.5, local AS number 65000
Route status codes: s - suppressed, * - valid, > - active, E - ECMP head, e - ECMP
                    S - Stale, c - Contributing to ECMP, b - backup
                    % - Pending BGP convergence
Origin codes: i - IGP, e - EGP, ? - incomplete
AS Path Attributes: Or-ID - Originator ID, C-LST - Cluster List, LL Nexthop - Link Local Nexthop
          Network                Next Hop              Metric  LocPref Weight  Path
   %     RD: 100.250.250.11:100 auto-discovery 110100 0000:0000:0000:0000:0000
                                 100.250.250.11        -       100     0       i
   %     RD: 100.250.250.12:100 auto-discovery 120100 0000:0000:0000:0000:0000
                                 100.250.250.12        -       100     0       i


The reason is "invalid" in the output of show bgp evpn detail

RR1.12:10:27#sh bgp evpn route-type auto-discovery detail
BGP routing table information for VRF default
Router identifier 100.250.250.5, local AS number 65000
BGP routing table entry for auto-discovery 110100 0000:0000:0000:0000:0000, Route Distinguisher: 100.250.250.11:100
 Paths: 1 available
  Local (Received from a RR-client)
    100.250.250.11 from 100.250.250.11 (100.250.250.11)
      Origin IGP, metric -, localpref 100, weight 0, invalid, internal, pending resolution
      Extended Community: Route-Target-AS:65000:100 TunnelEncap:tunnelTypeMpls L2 Attributes: control word
BGP routing table entry for auto-discovery 120100 0000:0000:0000:0000:0000, Route Distinguisher: 100.250.250.12:100
 Paths: 1 available
  Local (Received from a RR-client)
    100.250.250.12 from 100.250.250.12 (100.250.250.12)
      Origin IGP, metric -, localpref 100, weight 0, invalid, internal, pending resolution
      Extended Community: Route-Target-AS:65000:100 TunnelEncap:tunnelTypeMpls L2 Attributes: control word

Here is the BGP configuration:

RR1.11:59:52#sh run sec router bgp
router bgp 65000
   router-id 100.250.250.5
   no bgp default ipv4-unicast
   neighbor RRC peer group
   neighbor RRC remote-as 65000
   neighbor RRC update-source Loopback0
   neighbor RRC route-reflector-client
   neighbor RRC send-community extended
   neighbor 100.250.250.11 peer group RRC
   neighbor 100.250.250.12 peer group RRC
   neighbor 100.250.250.21 peer group RRC
   neighbor 100.250.250.22 peer group RRC
   !
   address-family evpn
      neighbor RRC activate

Add "neighbor default encapsulation mpls next-hop-self source-interface Loopback0" under EVPN AF

RR1.12:20:00(config)#router bgp 65000
RR1.12:20:02(config-router-bgp)#address-family evpn
RR1.12:20:04(config-router-bgp-af)#neighbor default encapsulation mpls next-hop-self source-interface Loopback0

One prefix shows "* >" - valid. One shows no code

RR1.12:20:10#sh bgp evpn
BGP routing table information for VRF default
Router identifier 100.250.250.5, local AS number 65000
Route status codes: s - suppressed, * - valid, > - active, E - ECMP head, e - ECMP
                    S - Stale, c - Contributing to ECMP, b - backup
                    % - Pending BGP convergence
Origin codes: i - IGP, e - EGP, ? - incomplete
AS Path Attributes: Or-ID - Originator ID, C-LST - Cluster List, LL Nexthop - Link Local Nexthop

          Network                Next Hop              Metric  LocPref Weight  Path
         RD: 100.250.250.11:100 auto-discovery 110100 0000:0000:0000:0000:0000
                                 100.250.250.11        -       100     0       i
 * >     RD: 100.250.250.12:100 auto-discovery 120100 0000:0000:0000:0000:0000
                                 100.250.250.12        -       100     0       i

Details still shows "invalid"

RR1.12:22:09#sh bgp evpn route-type auto-discovery rd 100.250.250.11:100 detail
BGP routing table information for VRF default
Router identifier 100.250.250.5, local AS number 65000
BGP routing table entry for auto-discovery 110100 0000:0000:0000:0000:0000, Route Distinguisher: 100.250.250.11:100
 Paths: 1 available
  Local (Received from a RR-client)
    100.250.250.11 from 100.250.250.11 (100.250.250.11)
      Origin IGP, metric -, localpref 100, weight 0, invalid, internal
      Extended Community: Route-Target-AS:65000:100 TunnelEncap:tunnelTypeMpls L2 Attributes: control word
      MPLS label: 132768

No tunnel endpoint in "show tunnel rib brief"

RR1.12:22:50#show tunnel rib brief | grep 250.250.1
   100.250.250.1/32               IS-IS SR IPv4       6               65                      115               20
   100.250.250.12/32              IS-IS SR IPv4       4               65                      115               40

The cause is the PE's config, missing node-segment ipv4 configuration

PEa1.12:10:13#sh run int lo0
interface Loopback0
   ip address 100.250.250.11/32
   ipv6 address 2000:100:250:250::11/128
   node-segment ipv6 index 11
   isis enable MplsSR
   isis passive

PEa1.12:25:24#c
PEa1.12:26:08(config)#int lo0
PEa1.12:26:10(config-if-Lo0)#node-segment ipv4 index 11

On RR1, NH emerges in tunnel rib. 

RR1.12:22:56#show tunnel rib brief | grep 250.250.1
   100.250.250.1/32        IS-IS SR IPv4       6               65                      115               20
   100.250.250.11/32       IS-IS SR IPv4       2               65                      115               30
   100.250.250.12/32       IS-IS SR IPv4       4               65                      115               40

And bgp table is good

RR1.12:24:51#sh bgp evpn
BGP routing table information for VRF default
Router identifier 100.250.250.5, local AS number 65000
Route status codes: s - suppressed, * - valid, > - active, E - ECMP head, e - ECMP
                    S - Stale, c - Contributing to ECMP, b - backup
                    % - Pending BGP convergence
Origin codes: i - IGP, e - EGP, ? - incomplete
AS Path Attributes: Or-ID - Originator ID, C-LST - Cluster List, LL Nexthop - Link Local Nexthop

          Network                Next Hop              Metric  LocPref Weight  Path
 * >     RD: 100.250.250.11:100 auto-discovery 110100 0000:0000:0000:0000:0000
                                 100.250.250.11        -       100     0       i
 * >     RD: 100.250.250.12:100 auto-discovery 120100 0000:0000:0000:0000:0000
                                 100.250.250.12        -       100     0       i

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