Prepare OOB to be usable as emergency server uplink

[Firefishy]

The out-of-band Raspberry Pi devices we have in Amsterdam and Dublin has their own independent uplink to the Internet via private 4G network (1NCE).

We should pre-configure these devices to be usable as a potential backup uplink in the event of a full ISP outage.

[Firefishy]

Likely pre-configure NAT and likely site to site wireguard over 4G connection.

[pnorman]

Do these have enough bandwidth to work as an uplink between sites?

[Firefishy]

Do these have enough bandwidth to work as an uplink between sites?

The Teltonika TRM240 4G modem we use supports up to 10 Mbps download / 5 Mbps upload.

Which should be sufficient for syncing a small amount of unsynced (tail) of postgres WAL logs, diffs and osmdbt state.

The new Teltonika TRM500 5G modem supports up to 3.4 Gbps, but we'd hit the 1nce 500MB data limit very quickly. Top-up is €10 per 500MB.

[pnorman]

If we're able to handle a complete site outage (e.g. power goes down or both switches go down) would we still need the OOB uplink?

[Firefishy]

If we're able to handle a complete site outage (e.g. power goes down or both switches go down) would we still need the OOB uplink?

Nothing runs if both power or both switches down. The out-of-band has dual feed power and has serial links to both PDUs and both Switches and can recover from complete config loss.