I don't understand what the purpose of the link you posted is either, there is nothing there that is of any use, ?
How ever, the key words:
ipv6 not working anymore Do yield a lot of results that could be of use. EG:
This problem can occur for a number reasons, depending on various circumstances. To address the issue, you might need to update network drivers, disable the IP helper service, reset IPv6 settings, release and renew your IP configuration, etc. In the guide below, we describe various methods to fix the ipv6 not working anymore problem
OMG FINALLY.
Called Starhub last evening and greeted with support staff who insisted Starhub does not have IPv6. I've been running IPv6 on Starhub reliably untill the outage a few days back. Right now, under my router settings, IPv6 address is blank. Wasted my time last night downgrading my firmware and upgrading it when I realised the fault was with Starhub.
dusatvoj> I don't know if it's the nftables issue only or if it's some kernel issue but it seems broken now and I don't know what's wrong.
I don't know either, but I do not think it is a kernel issue, but considering you do not tell us what kernel, nor Debian version you are using, or anything, Nor what router is involved, eg: the above was "Starhub", and the problem specific to that, .. so any way, maybe some better details would help.
There is a command you can use as well:
https://manpages.debian.org/buster/ipro ... .8.en.html
DESCRIPTION
The ip utility can monitor the state of devices, addresses and routes continuously. This option has a slightly different format. Namely, the monitor command is the first in the command line and then the object list follows:
Per:
https://serverfault.com/questions/97060 ... able-linux
Thanks @A.B. I did some reading on ARP flux, and as it turns out, according to the sources I read, we had already set up our sysctl parameters to prevent this issue(arp_announce = 2 and arp_ignore = 1). So I don't think that's what's getting us. Going back to "ip -ts monitor", from the output I see that routes on our system become "STALE", and then are "PROBE"d and set to "REACHABLE", which I'm assuming means they responded to the probe. Would a route be removed if the router didn't respond? What happens if there's heavy traffic and the response packet happens to get dropped?
run instead: ip -ts monitor link , ip -ts monitor address , ip -ts monitor route. stale reachable etc is about ARP (with ip neighbour) and thus not about routes. –
==== for more details, below=====
https://www.startpage.com/do/dsearch?qu ... sion=1.3.0
There are so many things that could be causing this, you will need to just start the process of elimination, check the router, if it is ok, check the firmware , and so on,.....Keep notes on what you check and try, so we don't suggest something you all ready tried.