UK ISP Zen Internet has warned subscribers that their IP addresses will shortly change, with some facing a reduction in their address count down to one.

The change is all about migration - in this case a move from IPv4 - and users are being given 30 days of notice. For many, the change will result in half a minute of downtime while the changeover happens. For others, things are a bit more significant.

The biggest upset will come to users with multiple IP addresses. According to Zen: "If you already had multiple IP addresses as part of your paid package, then we have assigned you the same amount of new IP addresses."

However, if you were provided multiple addresses outside of an allocated package, then the kindly ISP will be cutting the number of addresses down to one. Customers who want to keep their IP address count can purchase additional addresses from Zen.

A Register reader who has been a Zen customer for just over a decade got in touch to express disquiet at the news. Our reader's /29 assignment first came with a consumer-grade ADSL package and was retained with the move to FTTC.

After the alarming news that the assignment would be reduced to a single IP address, Zen agreed to assign a new /29, but has yet to confirm the range.

"It will be majorly disruptive, as 30 days is hardly time to change 10 years of infrastructure. I’ve got firewalls and different VLANs running for differing purposes - eg: IoT device traffic egressing on a separate IP etc..."

Changing one's infrastructure to deal with the shift is going to be interesting. Users with a Zen-supplied router will need, at worst, to reboot their device. Customers with their own routers or more complicated setups featuring kit such as firewalls, VPNs, or mail servers, will have a considerably more torrid time.

Zen also warned that it would not be possible for customers to test the new IP addresses in advance "due to how IP addresses are assigned to the service." However, some with appropriate hardware might be able to check out the new range ahead of time "to reduce any potential downtime."

The Register contacted Zen regarding costs and to see if there will be possible credit for inconvenienced customers. We'll update the story should the ISP respond.

The Rochdale-based business has regularly won awards for its technology. However, in 2021, Zen's customer service delivered a less than stellar performance by suggesting to a disgruntled customer that they send a letter to a local Member of Parliament to help deal with poor connectivity.

More recently, the provider has sought to explain the benefits of leased lines and extol the virtues of Mesh Wi-Fi services in a business context.

Far be it from us to wonder how either service would function if an IP address were to be abruptly changed. ®

https://www.theregister.com//2024/01/31/zen_internet/