3

I have been having networking issues, now out of the blue my IPv6 does not appear, my router is set up for IPv6 and I have looked through the logs. I am running Ubuntu Server 20.04 ip address

root@sturtz001:/etc# ip address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp0s25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:23:24:08:58:1f brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.8/24 brd 192.168.1.255 scope global dynamic enp0s25
       valid_lft 86091sec preferred_lft 86091sec
    inet6 fe80::223:24ff:fe08:581f/64 scope link 
       valid_lft forever preferred_lft forever
3: ens2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether 00:1b:21:bf:e7:28 brd ff:ff:ff:ff:ff:ff

cat /etc/netplan/*.yaml

# This is the network config written by 'subiquity'
network:
  version: 2
  renderer: NetworkManager
  ethernets:
    enp0s25:
       dhcp4: yes
       dhcp6: no
       accept-ra: true
    ens2:
       dhcp4: no
       dhcp6: yes
       accept-ra: true
12
  • 1
    Please edit your question to show the result of the terminal command: cat /etc/netplan/*.yaml Welcome to Ask Ubuntu – chili555 Aug 28 '20 at 23:59
  • @chili555 Here you go – Nathaniel Sturtz Aug 29 '20 at 13:49
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    Right beneath and aligned exactly with version: 2 please add: renderer: networkd Then do: sudo netplan --debug generate followed by: sudo netplan apply Any improvement? It may take a reboot. – chili555 Aug 29 '20 at 15:02
  • I did that @chili555 I now am rebooting – Nathaniel Sturtz Aug 31 '20 at 18:28
  • I get 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever – Nathaniel Sturtz Aug 31 '20 at 18:31
4

Are you sure your ISP provides you with IPv6? My router is also set up for IPv6 (and IPv4) but my ISP only gives IPv4. I would have to ask them to change it if I wanted IPv6.

In my router interface I can see in the status that IPv6 is dissconnected. Maybe you could look there.

Edit: You could use Wireshark. I don't know how you should run it from CLI but it is possible and it should also show your IPv6 if you have any connections to or from it.

Wireshark Docs on CLI

Also note the Ubuntu Docs on Wireshark. You need to grant at least some privileges to your user.

16
  • Yes I am sure, I am in contact with them now – Nathaniel Sturtz Aug 28 '20 at 22:12
  • you could try wireshark – totalynotanoob Aug 28 '20 at 23:00
  • What is Wireshark? – Nathaniel Sturtz Aug 28 '20 at 23:14
  • it is basicly an analysis tool for all network traffic (even bluetooth). shows you all pakages with source and destination. – totalynotanoob Aug 28 '20 at 23:15
  • Oh Ok. Thank you, I will look into it – Nathaniel Sturtz Aug 28 '20 at 23:25
1

I contacted my ISP and they turned on the Ipv6 DNS IPv6 was already on but they told me to reboot my router so I did.

-1

If I am not mistaken, the IPv6 is shown right there:

inet6 fe80::223:24ff:fe08:581f/64 scope link 
9
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    fe80: is a link-local address, meaning that no valid IPv6 address was received from the DHCP server. – chili555 Aug 28 '20 at 21:34
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    oh, sorry. You learn new things every day. – RAID Aug 28 '20 at 21:38
  • Try this, it's harmless but useful www.testmyipv6.com – darth_epoxy Aug 28 '20 at 22:10
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    When I run wget -q -O - http://testmyipv6.com/ | grep -A1 myIPaddr | tail -n1 I get 199.66.15.46 – Nathaniel Sturtz Aug 28 '20 at 22:14
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    You might find some clues here askubuntu.com/questions/809853/ubuntu-16-04-ipv6-not-working – darth_epoxy Aug 29 '20 at 0:43

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