[SOLVED] Do not have access to IPv6: is this the fault of Linux, the router/modem, or the ISP?

grumpyskeptic · 08-08-2021, 09:55 AM

I am using Linux Mint 20.2 Mate.

According to https://test-ipv6.com/ and another similar website I do not have any access to IPv6.

How can I find out where the fault is?

Does Linux Mint forbid IPv6? In the past IPv6 was thought of as a security risk, I do not know if it still is. Where in the settings can I see if IPv6 is potentially active or not?

I have tinkered with my router/modem in the past so I may have turned it off perhaps, but I cannot find any mention of either IPv6 or IPv4 in its config file. Does it have some other name?

The website above says: "Your DNS server (possibly run by your ISP) appears to have no access to the IPv6 Internet, or is not configured to use it. This may in the future restrict your ability to reach IPv6-only sites."

Could the ISP (Talktalk UK) restrict access to IPv6 or is this very unlikely?

My router-modem is set up to use an external DNS Server for IPv4 rather than that of the ISP, but not for IPv6.

Thanks.

smallpond · 08-08-2021, 11:12 AM

Issue the command

Code:

ip a

Lines starting with inet are IPv4 addresses. Lines starting with inet6 would be IPv6. If you have no inet6 addresses then you have IPv6 disabled in Linux.

If you have inet6, then see if you have any neighbors:

Code:

ip -6 neighbor show

Mine gives the link-local address of my router:

Code:

fe80::9683:c4ff:fe02:3397 dev wlo1 lladdr 94:83:c4:xx:xx:xx router

If you get this far, then you can use dig and traceroute to see where you are blocked:

Code:

dig -t AAAA www.google.com
www.google.com.		87	IN	AAAA	2607:f8b0:4006:800::2004
traceroute -6 www.google.com

TB0ne · 08-08-2021, 12:10 PM

Quote:

Originally Posted by grumpyskeptic

I am using Linux Mint 20.2 Mate.

According to https://test-ipv6.com/ and another similar website I do not have any access to IPv6.

How can I find out where the fault is?

Does Linux Mint forbid IPv6? In the past IPv6 was thought of as a security risk, I do not know if it still is. Where in the settings can I see if IPv6 is potentially active or not?

I have tinkered with my router/modem in the past so I may have turned it off perhaps, but I cannot find any mention of either IPv6 or IPv4 in its config file. Does it have some other name?

The website above says: "Your DNS server (possibly run by your ISP) appears to have no access to the IPv6 Internet, or is not configured to use it. This may in the future restrict your ability to reach IPv6-only sites."

Could the ISP (Talktalk UK) restrict access to IPv6 or is this very unlikely?

My router-modem is set up to use an external DNS Server for IPv4 rather than that of the ISP, but not for IPv6.

You need to go back to your other thread where you're complaining about getting an updated router/modem (for FREE) from your ISP, and saying you don't want to use it. Congratulations; you may now be seeing the fruits of your labors. You're running an old device, most probably with old firmware, with settings you've 'tinkered' with...do not be surprised if things aren't working correctly.

And did you do ANY research at all before asking here??
https://community.talktalk.co.uk/t5/...s/td-p/2709406
https://community.talktalk.co.uk/t5/...y/td-p/2406789

Linux has supported IPv6 for some time now....call your ISP if you have questions.

grumpyskeptic · 08-09-2021, 02:30 AM

Quote:

Originally Posted by smallpond

Issue the command

Code:

ip a

Lines starting with inet are IPv4 addresses. Lines starting with inet6 would be IPv6. If you have no inet6 addresses then you have IPv6 disabled in Linux.

If you have inet6, then see if you have any neighbors:

Code:

ip -6 neighbor show

The result I get for the ip a command:

Code:

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: enp0s7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:1a:a0:4c:ab:c2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.4/24 brd 192.168.1.255 scope global dynamic noprefixroute enp0s7
       valid_lft 84336sec preferred_lft 84336sec
    inet6 fe80::ff15:3057:1c3c:7de6/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

When I type in ip -6 neighbor show, nothing is shown. I just get the prompt on the next line.

ondoho · 08-09-2021, 03:45 AM

Quote:

Originally Posted by TB0ne

You need to go back to your other thread where you're complaining about getting an updated router/modem (for FREE) from your ISP, and saying you don't want to use it. Congratulations; you may now be seeing the fruits of your labors. You're running an old device, most probably with old firmware, with settings you've 'tinkered' with...do not be surprised if things aren't working correctly.

Thank you again for your incessant detective work!
It's always the info OP doesn't provide that turns out to be crucial, isn't it.

TB0ne · 08-09-2021, 07:54 AM

Quote:

Originally Posted by grumpyskeptic

The result I get for the ip a command:

Code:

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: enp0s7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 00:1a:a0:4c:ab:c2 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.4/24 brd 192.168.1.255 scope global dynamic noprefixroute enp0s7
       valid_lft 84336sec preferred_lft 84336sec
    inet6 fe80::ff15:3057:1c3c:7de6/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

When I type in ip -6 neighbor show, nothing is shown. I just get the prompt on the next line.

Did you bother to read the links that (apparently) had to be looked up for you?? The ones from your ISP, stating the availability of IPv6??

Did you also bother to think about the fact your router is not only old, but unsupported (at this point), and 'tinkered with'?? Don't you think that would have bearing on things??

TB0ne · 08-09-2021, 07:55 AM

Quote:

Originally Posted by ondoho

Thank you again for your incessant detective work! It's always the info OP doesn't provide that turns out to be crucial, isn't it.

Not really detective work; I responded in the OP's other thread, so I knew of it.

grumpyskeptic · 08-23-2021, 07:12 AM

Quote:

Originally Posted by TB0ne

And did you do ANY research at all before asking here??
https://community.talktalk.co.uk/t5/...s/td-p/2709406
https://community.talktalk.co.uk/t5/...y/td-p/2406789

Thanks, I thought it very unlikely that an ISP would not be allowing or providing IPv6 access in 2021, so I did not search for it. But the second thread above has recent 2021 posts that say that indeed it does not give IPv6 access.

Am I missing anything by having no access to IPv6?

hazel · 08-23-2021, 09:34 AM

Interesting thread. I've been wondering for some time why my Slackware system always tries to start up ipv6 at boot and then falls back to ipv4. /sbin/ip -6 neighbor gives me nothing, so probably my router doesn't support that protocol. That's not surprising as it's very old equipment.

I'd be interested in the answer to grumpyskeptic's question.

Quote:

Originally Posted by grumpyskeptic

Am I missing anything by having no access to IPv6?

TB0ne · 08-23-2021, 10:54 AM

Quote:

Originally Posted by grumpyskeptic

Thanks, I thought it very unlikely that an ISP would not be allowing or providing IPv6 access in 2021, so I did not search for it. But the second thread above has recent 2021 posts that say that indeed it does not give IPv6 access.

Am I missing anything by having no access to IPv6?

You tell us; is there anything you can't access that you need/want to access by NOT having it?? And again, the information provided was readily available to you, before you posted this thread.

computersavvy · 08-23-2021, 04:55 PM

Many ISPs, even today, do not provide IPv6 networks.
1. There is a cost to the equipment.
2. Not everything on the internet requires IPv6 and everything is required to remain IPv4 compatible
3. Many major interlink trunks still are not 100% IPv6 compatible even after 20+ years of progress.

Only you can tell us if something you NEED is blocked by lack of IPv6 acceess.

ondoho · 08-24-2021, 02:00 AM

IPv4 addresses have run out already. "Mitigation efforts" have been applied for decades, but there will come the time when that just won't cut it anymore.

There even might be a few already that are only accessible via IPv6, although I do not think so. You can play around with 'ping -4 $IP' to see if you find one.