This obscure and minor problem - of me getting access to a single classic-car forum site - is providing me with a window into what seems a complex world of how-internet-connections-work. So thanks, first of all, to everyone who has posted. For me it is a real learning experience.

I'll try to respond to various of the points that have been made in the most recent half-dozen posts.

1) I don't know how Zen assigns IP addresses, what their range of addresses might be, and whether mine is static or dynamic. As @pheasant rightly observes, I just need a connection and an IP address that works for browsing etc. I'm not fussed or wedded to a specific set of numbers;

2) I did try powering off my Zen Fritzbox router soon after the problem first emerged. But just for 5 minutes or so, not an hour. So I don't know whether - as @ian72 - comments - this might result in a change to the IP address, either to something totally different , or to a "sticky" one that is in the same range, or indeed the same IP address as before... Is it worth powering down for a much longer period to see what if any difference that might make?

3) I like @andrue's analogy of a taxi (Zen) taking me to a nightclub (fiero.nl) whose bouncer then turns me away. Helps me to understand why Zen isn't bothered and won't do anything.

4) pretty much everyone seems to agree that either the specific IP address, or a range used by Zen, has been blacklisted somewhere along the transmission chain. My earlier post giving the result of my 'traceroute' command shows that the connection stops, or is timed out, at the 11th to 13th "hops", by a server at wd6.net, We can all make guesses as to why (eg dodgy behaviour by a previous user of the IP address..). For what it's worth this classic-car technical forum is hardly the sort of site that might generate bad behaviour by those who visit, and not the sort of forum where admins have to ban people for inappropriate comments or conduct!)

5) I have reached out to the fiero.nl website admin.... and got a reply, confirming that he/they have not blocked, banned or blacklisted my IP address. I have sent him a copy of the traceroute result which shows where the connection is blocked or timed out, and now wait to see what further insight or explanation they can provide.

So the investigation continues.....

Edited by br1anstorm (Tue 18-Feb-25 20:00:20)

2) I did try powering off my Zen Fritzbox router soon after the problem first emerged. But just for 5 minutes or so, not an hour. So I don't know whether - as @ian72 - comments - this migh result in a change to the IP address, either to something totally different , or to a "stcky" one that is in the same range, or indeed the same IP address as before... Is it worth powering down for a much longer period to see what if any difference that might make?

30 minutes should do it. If you can live with it off overnight. Switch it off after you go to bed and light it up in the morning

3) I like @andrue's analogy of a taxi (Zen) taking me to a nightclub (fiero.nl) whose bouncer then turns me away. Helps me to understand why Zen isn't bothered and won't do anything.

It's a good analogy by @andrue. The bouncer at the club doesn't like the colour of the car you've turned up in. If you turn up in another coloured car he should let you in. 😂

5) I have reached out to the fiero.nl website admin.... and got a reply, confirming that he/they have not blocked, banned or blacklisted my IP address. I have sent him a copy of the traceroute result which shows where the connection is blocked or timed out, and now wait to see what further insight or explanation they can provide.

In that case, I really think you'll need to ask Zen to assign you from a different / fresh IP range, away from what you have. Try the router power down first through as per @ian72 suggestion. Otherwise, Zen have plenty of IP ranges to choose from...😅

51.148.0.0/16
51.155.0.0/16
62.3.64.0/18
77.104.128.0/18
82.68.0.0/15
82.71.0.0/16
88.97.0.0/18
88.97.64.0/19
88.97.96.0/20
88.98.0.0/20
88.98.16.0/23
88.98.18.0/24
88.98.21.0/24
88.98.22.0/23
88.98.24.0/21
88.98.32.0/19
88.98.64.0/19
88.98.128.0/19
88.98.160.0/21
88.98.170.0/23
88.98.172.0/22
88.98.176.0/20
91.235.214.0/24
146.66.64.0/18
185.81.232.0/22
188.122.32.0/20
188.122.60.0/23
185.6.135.0/24
185.169.116.0/23
185.169.118.0/23
185.183.100.0/22
188.122.48.0/21
188.122.56.0/22
188.122.63.0/24
193.19.156.0/23
212.23.0.0/19
217.155.0.0/16

2a02:8010::/29

Thanks @pheasant, that sounds like a plan. I'll try the overnight router switch-off and then see what happens when I try to reconnect tomorrow.

Interesting that Zen has such a selection of IP addresses to choose from. Their Tech Support people didn't offer the option of a change to a different address or range (another colour of taxi!) when I raised the issue with them.

Make a note of your external/public/WAN address tonight before you drop the router power. Make a note of again in the morning. Just so you can track the change, aids in diagnosis. I suspect you don’t have a fixed IP address.

The question really is how “sticky” it is. I don’t really know how sticky Zen’s addresses are.

I have an EE FTTP connection and that is sticky through router reboots, but anything longer and it will jump to a completely different range.

The list of IP subnets (ranges) above that Zen hold is purely illustrative. It doesn’t necessarily mean that they will be handing all of those out. They may be reserved for other purposes etc. But it gives you some idea of the scope of what could be assigned.

As another line of attack, is there a good enough mobile signal at your location that you could use your mobile phone as a hot spot and connect your computer to that? If you can do that and reach the site it points to your Zen identity being blocked. If you are still blocked it points to something in your system that is causing the problem. Have you run any sort of malware scan to make sure your machine hasn't been hijacked and is being used for nefarious purposes?

In reply to a post by astanden:

http://www.fiero.nl./

Works fine for me on Zen with a FritzBox.

In reply to a post by Woolwich:

Works fine - and very quick to load - from my Zen connection.

In reply to a post by Scottish_Pete:

Works fine for me on Zen, but not using a FB.

Whilst we wait for the OP to return after overnight router power down...

Can I ask each of you what public subnet / IP range you folks are assigned by Zen (don't reveal your entire public IP though - the first 3 octets are enough)?

Edited by Pheasant (Wed 19-Feb-25 09:28:45)

In reply to a post by Pheasant:

Can I ask each of you what public subnet / IP range you folks are assigned by Zen

I'm on 82.68.xxx.xx. On the other hand, just to stick another spanner in, maybe I was connecting over IPv6...

I can reach the site on Zen (static) IP range 217.155.*.*

If the OP is on Zen via CityFibre then I'm pretty sure it's a static IP. I don't know how it works via Openreach.

Edited by timo_w2s (Wed 19-Feb-25 12:02:54)

In reply to a post by Woolwich:

In reply to a post by Pheasant:

Can I ask each of you what public subnet / IP range you folks are assigned by Zen

I'm on 82.68.xxx.xx. On the other hand, just to stick another spanner in, maybe I was connecting over IPv6...

There is a handy extension for firefox, chromium, chrome and maybe others, called ipvfoo, which displays a little 4 or 6 in or near the url bar to indicate which IPv is in use. Until I installed ipvfoo, I too had no idea whether I was using IPv6, since there was absolutely no discernable difference once I got IPv6 connectivity.

In reply to a post by timo_w2s:

if the OP is on Zen via CityFibre then I'm pretty sure it's a static IP. I don't know how it works via Openreach.

Always been fixed IP on Zen for Openreach. I've had mine for 10 or 15 years.