Can't reach NS&I login page

[#1]

...A long time ago!

I have no idea how to independently prove or test this IP black hole theory. It suggests an approach to ATOS is needed. I don't fancy they would be very forthcoming if an anonynous individual started asking them out of the blue about the IP address ranges they used for the internal network for the secure logon site for NS&I! 😄

It might need an official approach by Plusnet, or even BT as the owner of Plusnet. All sounds a bit challenging... 

Could start by 'officially' raising the matter with NS&I. After all, as a client of theirs, I cannot now log on to my account.

Dear Sir...

[#2]

@pvmb 

"That is what is supposed to be the case. But, in my experience, lots of things that are not supposed to happen do happen."

That is certainly true.

For example, every device that is capable of connecting to the internet has a MAC address that is unique to that device and that device only, doesn't it?

Except that a few years ago, I bought my first Android TV box to play with. I was so impressed with it that I bought another one - same model and from the same company.

That's when the problems began: each box worked fine when it was the only one on my home network, but with both connected, neither worked.

It turned out that the boxes were exact clones - right down to having the same network MAC addresses!

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[#3]

@jab1 wrote:

"As I said, I'm no expert, but I do know that an IP range belonging to one entity can't be used by another."

@pvmb wrote: "OTOH, when I was actually working in IT I came across just such a case."

When I was working, we had control of an internal network of remote sites, which were not all permanently equipped. Our Field Teams were responsible for moving the equipment between sites as required. Each venue had its own set of unique IP addresses for the equipment, and it was part of the Field's responsibility to reprogram the kit after a move.

If they made a mistake, which wasn't uncommon, there was the potential for a clash of IP addresses and we could "see" the remote equipmentt.

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[#4]

@Mr_Paul  Was this a Intranet setup ?

[#5]

@Champnet 

Yes, I suppose it was.

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[#6]

So the Intranet IPs wouldn't conflict with the Internet IPs.................

[#7]

No, I was just giving a real world example, supporting what can happen when there is an IP address clash.

Moderator's note by Mike (Mav): Full quote of preceding post removed as per Forum rules.

[#8]

See attached letter (.doc format) to NS&I.

[#9]

Nice one, @pvmb 

[#10]

@pvmb 

Who at NS&I did you send that letter to?

Just a thought regarding the suggestion that NS&I's internal systems may inadvertently be using IP addresses allocated to some Plusnet customers:

I thought that IP address usage was defined by the first one or two octals? eg 192.xxx.xxx.xxx reserved for internal systems such as our home networks.

This gives some more info:

https://en.wikipedia.org/wiki/IPv4

ISTR that our internal network at work used addresses beginning 10.xxx.xxx.xxx

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[#11]

@Mr_Paul

I just sent it to NS&I, I hope they will direct it to an appropriate person or department.

My suggestion of a possible cause was just that, a suggestion. Something is obviously wrong somewhere and it seems to be IP address dependent. The important thing seems to be to draw their attention to the problem. Fundamentally, as a customer of NS&I I can no longer log on to my account - and the issue is clearly not just local to me.

When I previously phoned NS&I to report the matter I was left wondering if their acknowledgement of an 'intermittent issue' with logging in was this one, or was the problem some people have been reporting since NS&I introduced logging in using 2FA.

[#12]

I'm suspecting an oddity in IPv4 <-> IPv6 address space translation. But that is pure and utter speculation.

[#13]

@jab1  Wrote “I am not convinced it is a 'Plusnet' issue - I can't access it over my Zen connection, either, although I can reach the login page via the 'home' NS&I  site. Don't know if you can login from there - I don't have an NS&I account to try.”

it’s difficult to judge the extent of the problem as there is very little mention on the Internet. If all of Openreach customers are affected then it would be all over the news. I suspect a link between Openreach and Plusnet but @jab1 is proving to be an exception, no surprise there 🥴

[#14]

@Champnet My only 'Openreach' connection is the wires. Zen use their own DNS services.

[#15]

same issue for me, I contacted NS&I and they asked if I was on Plusnet, when I said I was they said there's something going on with PN's network and they need to fix it.
Plusnet, please get this fixed as I have no mobile data where I live so reply on you for my connection.