losing ipv6 connectivity

Usul · Mar 24, 2024

in /etc/rc.conf I have the following :

Code:

ifconfig_vnet0="up"
ifconfig_vtnet0_ipv6="inet6 2a07:8dc1:20:0:0045:d3ff:fe21:6c4c/128"
ipv6_defaultrouter="fe80::1%vtnet0"

This does not seem to give my machine ipv6 connectivity. Support for my isp suggested adding this to my root's crontab

Code:

*/1 * * * * /sbin/ping6 -c 1 fe80::1%vtnet0 >/dev/null

This has worked for a while, but after upgrading from 13.2 to 13.3. It's not working anymore as the crontab doesn't help.
If I run the command I'll get ipv6 connectivity :

Code:

root@debellum:~ # ping6 google.com
PING6(56=40+8+8 bytes) 2a07:8dc1:20:0:45:d3ff:fe21:6c4c --> 2a00:1450:4007:810::200e
16 bytes from 2a00:1450:4007:810::200e, icmp_seq=0 hlim=59 time=17.636 ms
16 bytes from 2a00:1450:4007:810::200e, icmp_seq=1 hlim=59 time=17.612 ms
^C
--- google.com ping6 statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/std-dev = 17.612/17.624/17.636/0.012 ms

But after a period of time it drops again.

I'd like to stabilize my IPV6 connection. What can I do to :
- Understand why I'm loosing ipv6
- fix it

Thanks

PMc · Mar 24, 2024

Can be lots of creepy things.
First step might be open new terminal and run some tcpdump -nivtnet0 icmp6 and watch what's happening. If nothing goes out the problem s Your's, if nothing comes back the problem is upstream.

If the isp suggests to run continuous ping, they seem to have doubtful connectivity, to put it mildly.

On a couple of sites I'm using HurricaneElectric tunnels and not bother with the local provider's stuff. These are free, and therefore no guarantee, but at least these people seem to know very well what they are doing, and it works.

Usul · Mar 24, 2024

PMc said:
Can be lots of creepy things.
First step might be open new terminal and run some tcpdump -nivtnet0 icmp6 and watch what's happening. If nothing goes out the problem s Your's, if nothing comes back the problem is upstream.

If the isp suggests to run continuous ping, they seem to have doubtful connectivity, to put it mildly.

On a couple of sites I'm using HurricaneElectric tunnels and not bother with the local provider's stuff. These are free, and therefore no guarantee, but at least these people seem to know very well what they are doing, and it works.

Thanks for both ideas.

drhowarddrfine · Mar 24, 2024

Losing is spelled l-o-s-i-n-g

gotnull · Mar 25, 2024

drhowarddrfine said:
Losing is spelled l-o-s-i-n-g

Yeah I do that mistake a lot too, I've learned not so long ago the difference between "loose" and "lose", thank you to bring this up. I wish native English speakers do that more often because it helps more than it hurts.

drhowarddrfine · Mar 25, 2024

gotnull said:
I wish native English speakers do that more often because it helps more than it hurts.

Years ago, when I would correct people on reddit, I would get downvoted into oblivion for doing that and receive all kinds of snide remarks. Which shows the quality level of reddit posters and why I haven't gone there in at least a decade.

gotnull · Mar 25, 2024

I know some people can be upset by remarks about the way they speak or type, but grammar is like code if no one shows you your own mistake how could you ever learn? I think it's a normal process.
Plus that's the only time I see this kind of post since I do use this forum, don't be afraid to do it more, if it can make us(no native English speakers) better in English it's a win win situation.
Sorry for the off topic guys.

Usul · Mar 25, 2024

I don't mind being corrected.

gotnull · Mar 28, 2024

Usul said:
I don't mind being corrected.

wise man

I use IPV6 since 3 months only so it's still new for me and I am not really confortable with its settings (I try to learn it but verrrryyy slowly ...)
I can't say it's a bad experience, I tried both IPV4 only & IPV6+IPV4 and to be honest it's smoother with IPV6. While IPV4 is not bad I can definitively see some slowdowns from time to time when browsing the internet.
It looks like you are in IPV6 only, did you try IPV6+IPV4?

I just have this basics settings in my rc.conf:

Code:

ifconfig_em0="DHCP"
ifconfig_em0_ipv6="inet6 accept_rtadv"
defaultrouter="192.168.x.x"

grahamperrin · Mar 30, 2024

No problem with 15.0-CURRENT and an occasional tunnel (to 192.168.1.10 using em(4)), up by default when I start the OS. I routinely take it down after logging in:

ifconfig gif0 down && ifconfig wlan0 down

My rc.conf includes:

Code:

ipv6_activate_all_interfaces="NO"
ipv6_defaultrouter="…"

cloned_interfaces="gif0"
create_args_gif0="tunnel 192.168.1.10 … mtu 1480"
ifconfig_gif0_ipv6="inet6 … … prefixlen 128 NOAUTO"

netif_nic_seq="em0 wlan0 gif0"

wlans_iwm0="wlan0"
create_args_wlan0="country GB regdomain etsi"
ifconfig_wlan0="WPA DHCP"

ifconfig_em0="DHCP"

Usul said:
… after upgrading from 13.2 to 13.3. It's not working anymore …

Can we see anything between the two that might indirectly cause instability?

<https://cgit.freebsd.org/src/tag/?h=release/13.2.0>..<https://cgit.freebsd.org/src/tag/?h=release/13.3.0>

<https://cgit.freebsd.org/src/log/?h=releng/13.3&qt=range&q=525ecfdad597980ea4cd59238e24c8530dbcd31d..80d2b634ddf0b459910b54a04bc09f5cbc7185a7>

Postscript

Ludovic, c'est le Rasbperry Bi 3b+ qu'on a utilisé en 2021, ou quoi ?

losing ipv6 connectivity

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