IPv6 Causing Slowness and Ping Issues

Yes, I’m still running Leap 15.1, mainly to make sure my system is “stable” for work…

… and now the problem…

My system used to work well with IPv6 enabled, but recently, it has caused pings to report network unreachable (with domain resolved as IPv6 address), upload speed < 1 Mbps, and slow response when trying to get to websites. However, download speed is unaffected.

I vaguely remembered problems with IPv6 before, so I turned it off and everything is fast again.

Anybody know if this issue is something with my system, even though there hasn’t been many system level updates to Leap 15.1? Or if it’s an ISP issue?


The positive point about using 15.1 is that you are sure that there were no updates anymore that could have caused this. Thus one may assume that it is an ISP thing.

The negative side of running 15.1 is that almost nobody here has it anymore and that thus similar experiences will be near to nil.

Please inspect the settings in the files located in the directory /etc/sysconfig/network/.

Please inspect the IPv6 settings of your Router – especially with respect to the IPv6 configuration your ISP has setup for your Router.

Does “dig -t AAAA «hostname of your Router»” indicate anything strange?

Please take a look at the output of “inxi --admin --ip” – there should be 3 IPv6 addresses mentioned – “type: temporary dynamic scope: global” – “type: dynamic mngtmpaddr scope: global” – “scope: link” …

  • Please do not post the output here
    – unless, you’re absolutely certain that, the IP addresses listed are not accessible from the Internet …

Possibly some security certificate is expired. With OS updates you will get new, without ones you need to update it manually.

I’m not sure what I’m looking for in /etc/sysconfig/network/. The only thing I’ve done is disabled IPv6 within YaST/Network Settings/Global Options. I see the file “config” as updated, but not sure which setting in that file would be problematic. Things have been working with IPv6 for months, until now…

The Router settings haven’t changed and similarly, have been working. What things would the ISP be able to set? Nameservers?

dig -t AAAA <router IP> returns very quickly, both on IPv4 or IPv6, with the same output.

inxi --admin --ip

  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Micro-Star MSI driver: r8169 v: 2.3LK-NAPI port: b800 
  bus ID: 04:00.0 chip ID: XXXX:XXX 
  IF: eth1 state: down mac: XX:X:X:X:X:X 
  Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet 
  vendor: Micro-Star MSI driver: r8169 v: 2.3LK-NAPI port: c800 
  bus ID: 05:00.0 chip ID: XXXX:XXX
  IF-ID-1: eth0 state: up speed: 100 Mbps duplex: full 
  mac: XX:XX:XX:XX:XX:XX 
  IP v4: XXX.XXX.X.XXX/24 scope: global broadcast: XXX.XXX.1.255 
  IP v6: XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX/64 type: temporary dynamic 
  scope: global 
  IP v6: XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX:XXXX/64 type: mngtmpaddr dynamic 
  scope: global 
  IP v6: XXXX::XXXX:XXXX:XXXX:XXXX/64 scope: link 

Hmm… I do plan to update at some point, but not til the project wraps…

Install Leap 15.2 on a spare drive and test it.

I usually do an in-place update to a netbook first, then do it to my desktop. Unfortunately, one day, the netbook just stopped posting. It would turn on and immediately off. I thought it might be the CMOS battery, tried to replace it (which entailed soldering), but it still wouldn’t post. Subsequent time on forums revealed that posting should still work even if the CMOS battery stopped supplying juice; the BIOS settings would be lost and no time would be kept.

It might be time to buy a new drive…

You may take drive from notebook.

I’m on Leap 15.2 now and the IPv6 problem still persists, which means it’s likely an issue with the ISP?

I stumbled into this post by incident. It is still a 15.1 thread. Wouldn’t it been better to draw attention to your problem with a fresh thread?

Maybe? Am I missing anything if I don’t move to IPv6 at this point? I know we’re all supposed to migrate over to IPv6 one day…

I continued on with the thread since one suggestion was to upgrade to 15.2, which I was finally able to do, after my project wrapped.

I can not decide that for you. I have IPv6 on my systems for years on end and can really not tell if a connection is using IPv4 or IPv6. Even these forums can be connected to using IPv6 and I do not know what is used between the forums and my system. Just a black box in real life.
And btw, you do not migrate, the world uses both. Some systems will have IPv4 addresses, some will have both, some will have IPv6 alone. In the letter case you will be unable to connect to such a site.

I repeat that this is a “15.1 End of Life” thread and when you now want to talk about a problem you have in 15.2 you will probably not get the audience you need. Continuing here is not in your interest. But it is up to you.

networkd/resolved is your friend: https://en.opensuse.org/Network_Management_With_Systemd