Suddenly unable to use a particular IP for any outbound traffic

[skymoose]

Hi, been using my NR5103E for a couple of months now without issue.
But today between 9am and midday something appears to have happened, and now I find I am unable to "see" a public IP on the internet which is a private Linux server i own. Its definitely router related as if i switch to a tethered connection on my phone i can use the server like normal. From the NR5103E I find i cannot even ping the IP address even though i know its there and alive and responsive. Obviously I dont want to share the IP ove the server im trying to get to in this post but would be happy to PM it to tech support for a test.

Is there some sort of IP blocking in force and has this IP been blacklisted perhaps?

[simon_kite]

I have had the same issue today/yesterday in South West. IPv4 not being routed. I switch to the phone APN three.co.uk on my router and it worked. Three support were not able to assist me on this

[Spud]

Changing APN from "3internet" to "three.co.uk" worked for me.

@skymoosethat's probably why your phone worked but router didn't.

[skymoose]

Called three broadband support this morning and had 2 calls with them which were both unfruitful. After being told it was my fault and nothing to do with Three infrastructure, I asked for a call back from someone who can understand the issue technically and can help with something like a packet trace to get to the bottom of the matter. The support lady on the phone (who was very polite and trying as hard as she could i'm sure) has said she'd get someone to call me back but i've heard nothing so far.

And then mysteriously at 12 midday today all the unreachable IPs suddenly became reachable again. Interestingly, a work collegue of mine also using the same ISP has experienced identical issues to me too today. Something has definitely been "fixed" at midday.

Got a job running every minute now to test network connectivity so if any further outages occur i'm be able to say exactly when they start and end.

[xxxx]

skymoose, so were they two different connections that didn't work and did? then your and Willow2492's and my and some others' problems are prob the same, https://community.three.co.uk/t5/Broadband/5g-Broadband-unable-to-connect-to-some-sites/td-p/24913 

[Willow2492]

That is exactly the problem I was facing. I may have fixed it for myself and for now. In the Broadband tab of the router settings I've changed the Cellular WAN from IPv4 to IPv4 IPv6 DualStack and all the sites previously not working are now working.

[Willow2492]

I've been experiencing similar but with some servers I don't own, and over a similar time. I've not been able to connect to some ip addresses including my work vpn portal and also a public server snbforums.com [45.77.76.174] among others.

I don't think my work vpn address is pingable but all the other servers seem to ping fine when connected to my partner's hotspot (a different network) but not when connected to Three home broadband or my mobile hotspot (Smarty, also Three).