Can't access some websites (but mobile connection is OK)

[pmosb]

I have an issue where 2 specific websites will not load, but they will load if I access them via a 4G tether. Other sites will load.  The email account in my client and FTP in Cyberduck for one of the sites (I own it) also does not work via BT - but does on mobile.

So this indicates it is not the websites at fault but the ISP I am trying to connect with: BT.  It is not a website hosting issue - neither are blacklisted nor old certificates.   It is not a parental control issue. It is not a device issue. 

Both sites worked on this ISP connection a week ago. Both work now for everyone except via my BT Ultrafast Broadband connection. Both work on mobile.

Nothing has been tweaked, nor the hub reset.

I am using a newish Smarthub2 which has (upto now) been faultless. I did have a similar issue 5 months ago (when I had a Smarthub1) so this indicates this is a BT server or DNS issue.  Other forum posts indicate this is a known issue with BT Tech support.  Secondly the admin password access using a browser to my Router no longer works... which is curious. The MyBT app does work but has no real functionality to help.

There are loads of threads on this forum of identical issues, all marked as "Solved" yet none of them have a solution.. so please don't mark this thread as solved until I say it is.

So has anyone experienced this and found a fix?

Can the DNS be changed in the SmartHub2 as it does seem more locked down than previous hubs?

[pippincp]

You cannot change DNS in the hub but you can change it on your device.

[pmosb]

Hi,

Thanks for the reply.  I don't think the issue is DNS but it would be good to rule it out.  I don't think adjusting to Google DNS on every one of my devices is a practical solution.  I'd rather BT acknowledge the problem and offer a fix.

Shame that the SmartHub 2 is not flexible.

[pmosb]

After 40 minutes wasted talking to BT Help - I got nowhere.  BT tech support consisted of a line check and that was the limit of her knowledge and she resolutely would not escalate to a tech support.  I was then blamed that it was my virus software and "BT can't help sort out my devices".  So she had completely missed the crux of the fault.

Anyhoo - I recalled the previous time with the Smarthub1 that a hard reset might work. So I disconnected the smarthub and powered down for 5 minutes (during the pointless call with BT so all was not wasted). Upon restart (but not factory reset) I noted that my public IP address was new - and that appears to have cleared the issue.   It appears that BT routers are not very sticky and the IP address changes regularly on power down.   I suspect this fault occurred on a power cut a week ago and the IP address was then reset.  In the past I have noticed there are good and bad/toxic IP addresses.  In the case of EE the prefix 2.xx.xx was more toxic than 95.xx.xx IPs.    So the solution is to reset your Public Ip until you get allocated one of the servers that does perform correctly.

[pmosb]

Update:

My solution only worked for 3 days.

My newly acquired Public Ip address  that gave me back access to the two websites that had previously been blocked was 86.xxx.xxx.xxx     Now those sites are unable to reload.   Do I reset my router again?   What has changed in the 3 days?

Note: One of the sites is my own Wordpress site and this issue also blocks the email address and ftp associated with this site.  If I switch off my wifi and access via 4G mobile then the site is fully accessible.

[pmosb]

I have exactly the same issue.  I did a reset of my router and a new IP address 86.xxx.xxx.xxx was created and the two blocked websites were then accessible. It lasted 3 days and now they are blocked again with the same IP address that previously worked.

This implies that maybe some IP addresses are blacklisted and that after a while the clean addresses become blacklisted. So what is it that is happening to these IP addresses?

I had a previous experience with EE when my 95.xxx IP address was fine but if you reset to 2.xxx then you'd have page stalling on specific websites.  It was never acknowledged by EE... so I just routinely reset until I got a non-toxic IP address.

I read elsewhere on a forum that BT Tech support reacted to a similar complaint and then did something in the back room/servers to clear the issue for a customer.   My experience of reporting this is the Tech support (not very tech at all) had never heard of this and "we have no reports of such issues it is virus software on your devices".  So no help there.

[pmosb]

The issue continues.   

86.137.xxx.x  was a toxic IP address for me.  Some sites blocked, often my own Wordpress site.  Overnight they became accessible again but I am minded to  force a reset of my public IP address (by power down the Router for 5 minutes)

So the implication is that some of BT's IP addresses they allocate to us are toxic and the back office BT servers blacklist sites, whilst other IPs do not.  So if you have had normal access to the web, then after a power cut or power down of your router you then discover some websites are taking a very long time to respond, then it maybe that your IP has changed to a "toxic" address.

[pippincp]

You are going down the entirely wrong road. The IP blacklist used by all ISP's is third party. It may not be the same on all ISP's use as there are several. It is also possible/probable your server uses one too. There are many ISP IP addresses appearing on a blacklist having been used for spam accounts in the past.

[pmosb]

Thanks for the swift reply.   So some of BT's IP addresses are blacklisted, by some 3rd parties (I understand that), but how do I determine which of the IP addresses BT serves up to me are toxic with blacklisted users?   I am getting a pretty high hit rate of failures to load sites these days.     

[pippincp]

Have you tried a google search for blacklisted IP Addresses? Have you tried changing DNS servers on one devices to see if it resolves the issue?