abrown38andClaude Opus 5.5
8ee430276c
- Which never-used pool address a new client gets: sequential (the lowest, as before), reverse or random, in the settings, a subnet or a single pool (FIRST-LAST:ORDER). When no never-used address is left, the one free the longest, whatever the order; returning clients keep theirs. - A subnet's pools are used in the order listed, or one at random weighted by its never-used addresses. Pools now keep the order they are given in (no more sorting by address). - CLI --address-order and --pool-order; --add-pool of an existing range changes its order in place. Web UI: per-pool order and a move-up button, pool and address order on the subnet and settings pages. - Kea's allocator: random is imported. Schema migration 5. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
113 lines
4.8 KiB
Markdown
113 lines
4.8 KiB
Markdown
# Moving from Kea
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`steward import kea` reads a Kea DHCPv4 configuration (`kea-dhcp4.conf`)
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and Kea's lease file, and makes them Steward's: clients keep their
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addresses, and reservations and options carry over.
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## Steps
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1. Install Steward and start it ([install.md](install.md)). While Kea
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serves the network, Steward serves nothing: it has no subnets yet.
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2. See what the import would do:
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```sh
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sudo steward import kea /etc/kea/kea-dhcp4.conf \
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--leases /var/lib/kea/kea-leases4.csv -n
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```
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It lists the subnets and reservations it would create, how it mapped
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things (`note:`), and what it can't bring over (`not imported:`).
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3. Import:
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```sh
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sudo steward import kea /etc/kea/kea-dhcp4.conf --leases /var/lib/kea/kea-leases4.csv
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```
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Steward now wants to serve the subnets. Its sockets can't open while
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Kea holds port 67: `steward status` says so, and stewardd retries
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every 30 seconds.
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4. Stop Kea:
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```sh
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sudo systemctl disable --now kea-dhcp4-server
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```
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Within 30 seconds Steward serves the interfaces (`steward status`).
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Clients renew with it as their leases come due. They keep their
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addresses, because their leases were imported.
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Going back is the same in reverse: stop Steward
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(`systemctl disable --now steward`) and start Kea. Kea still has its own
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lease file. Leases Steward handed out in between aren't in it, but Kea
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pings before it offers an address, and clients renew or rebind.
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## What is imported
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| Kea | Steward |
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|---|---|
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| `valid-lifetime` (global, shared network, subnet) | the settings' lease time, and subnets' own where they differ |
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| `option-data` (global, shared network, subnet, reservation) | options at the same level; a subnet gets its shared network's |
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| `subnet4`: `subnet`, `pools`, `interface` | subnets with their pools and interface |
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| `shared-networks` | their subnets, all on the shared network's interface |
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| `reservations` with `hw-address` or `client-id` and `ip-address`, `hostname` | reservations |
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| `decline-probation-period` | the decline hold |
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| `allocator` (global, shared network, subnet) | `random`: the subnet's pool and address order random. `iterative` and `flq` become the default order, the lowest never-used address (with a note for `flq`) |
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| `user-context.comment` or `comment` of a subnet | the subnet's comment |
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| the lease file: active and declined leases, and released ones | leases (the last line of each address wins) |
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Options are matched by Kea's names, which Steward uses too, or by code.
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Hex data (`"csv-format": false`) is read as hex.
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**Interfaces.** Every Steward subnet needs its interface. The import
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takes, in order:
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1. the subnet's (or its shared network's) `interface`;
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2. the interface on this server with an address in the subnet;
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3. the only interface in Kea's `interfaces-config`, when there is just
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one.
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When none of these applies, the import says which subnets need one. Give
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it with `--interface PREFIX=IFACE`, once per subnet:
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```sh
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sudo steward import kea kea-dhcp4.conf --interface 10.0.20.0/24=eth0.20
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```
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**Lease files.** Kea's memfile is a log, and its lease file cleanup moves
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older lines to `kea-leases4.csv.2`. Give both, older first:
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`--leases /var/lib/kea/kea-leases4.csv.2 --leases /var/lib/kea/kea-leases4.csv`.
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Leases outside the imported subnets are left out (the import says how
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many). Leases in a database (MySQL, PostgreSQL) can't be read. Export them
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with the lease commands hook (`lease4-get-all`) into a memfile first, or
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let clients get new leases.
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## What isn't imported
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The import lists these as `not imported:` instead of dropping them
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silently:
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* client classes, and pools or options tied to them;
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* options of a pool (Steward sets options per subnet) and options in other
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spaces (vendor option spaces);
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* reservations by `duid`, `circuit-id` or `flex-id`, and reservations
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without an `ip-address`;
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* relays (`relay`), `next-server`, `boot-file-name` and other BOOTP fields;
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* hooks, DHCP-DDNS, and any other section (`Dhcp6`, `Logging`, `Control-agent`).
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`<?include ...?>` isn't followed: paste the included files in first.
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Kea is **not authoritative** by default; Steward is. The import notes this.
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Steward answers a client asking for an address that doesn't belong on
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its interface with a NAK, so the client gets a correct one at once. If
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another DHCP server still shares one of the networks, turn this off:
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`steward settings set --authoritative off`.
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## Importing again
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Importing over an existing configuration needs `--replace`. A subnet
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with the same network, and a reservation with the same address, keep
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their IDs, and subnets keep the names given in Steward, since Kea has
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none. So importing the same file again changes nothing, and after an edit
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in Kea only the differences show. The import is one history entry: `steward
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history undo ID` takes it back, except for the imported leases.
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