Migration & testnet rollout

[ben-malbeclabs]

End-to-end rollout of flex-algo to testnet. Must be completed and signed off before any production deployment.

Milestone: RFC-18: Migration & Testnet Rollout
RFC: #3288
Notion runbook: RFC-18 Testnet Rollout Steps

---

Size: Medium

Pre-requisites:

• All RFC-18 PRs merged to main (including PR smartcontract,controller: RFC-18 devnet fixes — node segment assignment and community stamping #3648 — tenantless community stamping + node segment assignment)
• doublezero-admin built and available on testnet bare metal host
• Infra group_vars for testnet has doublezero_controller_flex_algo block
• Foundation keypair available on testnet bare metal host

Rollout steps:

1. Create multicast-only link — ny5t1-dz001 ↔ ld4t-dz001 (dot1q 1010, 10Gbps). This link will NOT be tagged with UNICAST-DEFAULT — dedicated to multicast traffic only.

2. Run migration — Initialize AdminGroupBits, create UNICAST-DEFAULT topology, run doublezero-admin migrate flex-algo. Verify all links tagged EXCEPT the multicast-only 1010 link. Verify all Vpnv4 loopbacks have flex_algo_node_segments populated. If 1010 link was inadvertently tagged, clear with --link-topology default.

3. Enable flex-algo — Set enabled: true, community_stamping.all: false. Deploy controller. Verify on all devices: show isis flex-algo (UNICAST-DEFAULT advertised), show traffic-engineering interfaces (admin-groups on all WAN interfaces except 1010), show isis flex-algo path (full table), show isis segment-routing prefix-segments (flex-algo SIDs). Verify 1010 sub-interface has NO admin-groups. Run QA.

4. Enable community stamping — incremental:

   • 4a Single device: community_stamping.devices: [<device-pubkey>]. Verify set extcommunity color 2 in route-map, algorithm UNICAST-DEFAULT in VRF routes on remote devices.
   • 4b Second device: Add second device to list. Verify both.
   • 4c All devices: community_stamping.all: true. Verify across all devices. Run QA.

Rollback: Set enabled: false and redeploy. Cleanly removes all flex-algo config from devices. Unicast falls back to algo 0. Validated on devnet — no connectivity impact.

Devnet validation: All 5 phases complete (2026-05-02). See Devnet Verification Log.

Sign-off: All steps pass with no traffic disruption before proceeding to production.

[ben-malbeclabs]

Status update (2026-04-10): Not started. Unblocked once PRs #3497 → #3512 → #3513 → #3514 → #3515 merge in order. Migration plan documented — activator must deploy before controller to handle the UNICAST-DEFAULT topology lookup at link activation.