VCF 4 - Failed to Validate the BGP Route Distribution
During a VCF 4 Bring-up of a single Management Domain, the validation tests passed all OK. But during the deployment, it failed during the NSX-T tasks, specifically on the "Verify BGP Route Distribution" - "Failed to validate the BGP Route Distribution result for edge with ID
My understanding of this error is because an Edge Node is not receiving routes from the ToR it's trying to peer to.
Looking into it, I saw Edge Node 2, had learnt routes for external networks, but only via Inter-SR from Edge Node 1. You can tell this by using:
1en02> vrf 1
2en02(tier0_sr)> get route
3
4Flags: t0c - Tier0-Connected, t0s - Tier0-Static, b - BGP,
5t0n - Tier0-NAT, t1s - Tier1-Static, t1c - Tier1-Connected,
6t1n: Tier1-NAT, t1l: Tier1-LB VIP, t1ls: Tier1-LB SNAT,
7t1d: Tier1-DNS FORWARDER, t1ipsec: Tier1-IPSec, isr: Inter-SR,
8> - selected route, * - FIB route
9
10Total number of routes: 118
11
12isr> * 0.0.0.0/0 [200/700] via 169.254.0.130, inter-sr-285, 11:31:55
13isr> * 172.31.176.0/24 [200/700] via 169.254.0.130, inter-sr-285, 11:31:55
14isr> * 172.31.177.0/24 [200/700] via 169.254.0.130, inter-sr-285, 11:31:55
15isr> * 172.31.178.0/24 [200/700] via 169.254.0.130, inter-sr-285, 11:31:55
16...
And when checking the peering status with it's neighbors:
1en02(tier0_sr)> get bgp neighbor
2BGP neighbor is 172.31.6.1, remote AS 65100, local AS 65000, external link
3 BGP version 4, remote router ID 0.0.0.0, local router ID 172.31.6.2
4 BGP state = Connect
You can see it's BGP state = Connect. This means it's waiting for a successful TCP negotiation with it's peer.
There was a misconfiguration with one of the ToR BGP settings. Once that was rectified and the BGP state was Established, we could continue on with the deployment.