xn17 currently has high packet loss because another server in the rack is under a DDoS attack. This is a shared colo rack so the datacentre is working on it.
Update: Connectivity is restored
Update2: Just got back from the datacentre, it looks like the motherboard failed or at least ACPI functionailty had completely stopped working. We’ve moved the drives into a different chassis (inc motherboard, psu, raid card etc) and service is now restored.