Users of UK Broadband ISP Zen Internet Face IP Address Change UPDATE2

Rochdale-based ISP Zen Internet has notified some customers about a network migration that will result in them being assigned a new Internet Protocol (IP) address or addresses, which for most users should only result in a brief service disruption and no major changes. But for a few customers it may be a bigger problem.

Most consumers tend to connect via broadband providers that use dynamic IP addresses (or shared addressing via nasty CGNAT), and so a change in your IP – however often it may occur – is somewhat par for the course. But in Zen’s case it’s worth remembering that they’ve long sold their packages alongside Static IP (IPv4 and IPv6) addresses as standard (i.e. the IP address shouldn’t change).

Static or Fixed IPs tend to be more associated with premium / business packages for advanced users, where customers are more likely to desire a fixed address because they’ll be hosting servers or domains, using bespoke VPNs or VLANs, have specific security requirements (e.g. the need to whitelist a specific IP to firewalls) or want to avoid problems with Carrier Grade NAT etc.

However, it’s also fair to say that sometimes ISPs need to migrate to a new network platform (this is usually a fairly rare event), which can make it difficult to retain the original static IPs during the migration – this appears to be what is now happening at Zen (here). Customers have also been given just 30-days’ notice of the change.

Zen’s Statement

Zen operates one of the largest independent data networks in the UK. We invest significantly for better performance, better resilience, and a network that operates without limits or restrictions. This means constant evaluation and evolution to ensure we are optimising resources.

As with all evolution, this sometimes requires change and the project where we are migrating IPV4 addresses is one such change as we look to consolidate our portfolio.

As state earlier, casual customers don’t really need to worry as, at most, you might see a brief connection drop that lasts around 30 seconds or may need to reboot your broadband router. But for anybody making more specific use of their static IP addresses, particularly those who have paid to harness a range of IPs, then this migration is likely to be a much bigger headache, particularly for network admins.

Speaking of those with multiple IP addresses, there’s another caveat. The FAQ page notes that customers who already had multiple IP addresses as part of your paid package should end up being assigned the same amount of new IP addresses. But anybody provided with multiple IP addresses “outside of an allocated package” will find that Zen are going to “adjust the amount of IP addresses down to one“. So if you want more than one, then it’s time to break out the £££.

One particular problem with this sort of change is that it’s not usually possible for customers to start using the new IP addresses before the migration occurs, which fuels a window of uncertainty and makes it hard for network admins to properly test everything that might be affected. In fact, only giving 30-days’ notice may not be enough for some users with a legacy of IT infrastructure to deal with, which is aptly highlighted by The Register. We have asked Zen to comment.

UPDATE 1st Feb 2024 @ 7am

Surprisingly, we still haven’t had an official response via Zen’s PR channels, which is unusual as they’re typically a bit more on the ball than this. But feedback from some of their customers suggests that only a small proportion of their base are being impacted by this change, although precisely how they define “small” from a connected base of 186,000 remains unclear.

The gist of the situation seems to be that only those who have been directly notified about the change are going to be impacted by it. But email is not the most reliable of communication methods, and invariably some messages could be missed or find their way into the depths of an unwatched anti-spam folder. Sadly, for now, there’s no other way for customers to verify if their IPs are among those due to be changed.

We continue to await some clarity from Zen.

UPDATE 2nd Feb 2024 @ 11:27am

We’ve finally got something concrete from Zen Internet on this.

A Zen Internet spokesperson told ISPreview:

“We are making a change to the static IPv4 addresses allocated to less than 2% of our broadband customers. These are specifically customers with IP addresses within the ranges 82.70.0.0/16 & 88.96.0.0/16. All impacted customers will be notified on or before 29th February 2024.”

Less than 2% gives us a range of between 1,860 to 3,720 customers, at least when looking at their reported broadband base. The fact that notifications are still going out also means that not everybody has been informed yet.