On 2022-05-09 2:43 a.m., Andrei Borzenkov wrote:

This is ipv6.ip6-privacy connection property. If it is not set explicitly, it defaults to whatever kernel configuration is (.../use_tempaddr). This may or may not be exposed by frontend and different frontends may default to different values. I am not familiar with current KDE code, but briefly looking in plasma-nm-applet git, this setting is exposed and default is to use default (pun unintended), i.e. kernel setting.

Is it possible to change it?  All I see in kernel settings is a check box to enable SysReq keys.

On 2022-05-09 9:17 a.m., Per Jessen wrote:

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Is it possible to change it?  All I see in kernel settings is a check box to enable SysReq keys. Look for the "use_tempaddr" in /proc/sys/net

I don't think that's the setting.  It's "1" on both my ThinkPad and desktop systems and SLAAC works properly on my desktop.  That setting allows privacy addresses to be used, in addition to a persistent address.  I don't think it prevents the persistent address from working.  On my desktop, also 15.3 but with network configured with Wicked, I get 1 persistent address and up to 7 privacy addresses, with a new one each day.

On 2022-05-09 10:10 a.m., Andrei Borzenkov wrote:

You provided vague description of your problem and got vague suggestion. Start with showing actual facts like "ip -6 a" and marking what is wrong.

I already stated that I only get dynamic addresses and no persistent address. wlan0: mtu 1500 state UP qlen 1000     inet6 fd48:1a37:2160:0:314d:2cb6:9ec9:c4c1/64 scope global temporary dynamic        valid_lft 85611sec preferred_lft 13611sec     inet6 fd48:1a37:2160:0:71f0:e1b4:77ce:12e4/64 scope global dynamic mngtmpaddr noprefixroute  <--- ???        valid_lft 85611sec preferred_lft 13611sec     inet6 2607:fea8:4c82:5900:314d:2cb6:9ec9:c4c1/64 scope global temporary dynamic        valid_lft 85611sec preferred_lft 13611sec     inet6 2607:fea8:4c82:5900:8d63:e1de:7def:14a8/64 scope global dynamic mngtmpaddr noprefixroute  <--- ???        valid_lft 85611sec preferred_lft 13611sec     inet6 fe80::2579:66fb:acb:bda0/64 scope link noprefixroute        valid_lft forever preferred_lft forever On the desktop system, I have this line, where the address is based on the MAC: inet6 fd48:1a37:2160:0:76d4:35ff:fe5b:f5fa/64 scope global dynamic mngtmpaddr This address is persistent and has survived for years, through even replacing my firewall computer and cable modem and updating openSUSE.  Also, the least significant 64 bits have remained through different prefixes, as they're based on the MAC.  On my ThinkPad, I can't even get an address that survives a reboot.

On 2022-05-09 11:18 a.m., Andrei Borzenkov wrote:

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wlan0: mtu 1500 state UP qlen 1000     inet6 fd48:1a37:2160:0:314d:2cb6:9ec9:c4c1/64 scope global temporary dynamic        valid_lft 85611sec preferred_lft 13611sec     inet6 fd48:1a37:2160:0:71f0:e1b4:77ce:12e4/64 scope global dynamic mngtmpaddr noprefixroute  <--- ???        valid_lft 85611sec preferred_lft 13611sec     inet6 2607:fea8:4c82:5900:314d:2cb6:9ec9:c4c1/64 scope global temporary dynamic        valid_lft 85611sec preferred_lft 13611sec     inet6 2607:fea8:4c82:5900:8d63:e1de:7def:14a8/64 scope global dynamic mngtmpaddr noprefixroute  <--- ??? This is global non-temporary address.

Well, let's see how long it lasts.  It was different addresses yesterday.

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       valid_lft 85611sec preferred_lft 13611sec     inet6 fe80::2579:66fb:acb:bda0/64 scope link noprefixroute        valid_lft forever preferred_lft forever

On the desktop system, I have this line, where the address is based on the MAC: inet6 fd48:1a37:2160:0:76d4:35ff:fe5b:f5fa/64 scope global dynamic mngtmpaddr

Nothing requires to use MAC for building address. What is the output of

I never said it required the MAC, only that's what mine uses.  The persistent address can be based on the MAC or a random number, but either way it shouldn't change.  I prefer to use the MAC, but can live with a random number.  On the other hand, the privacy addresses are always based on a random number, with a new one every day.

On 2022-05-09 2:51 p.m., Andrei Borzenkov wrote:

No, they are not. Again, without seeing actual information from your system it is just pure speculation, but NetworkManager builds these addresses based on machine ID, stable secret, connection UUID and interface name. Unless these addresses fail DAD they should remain the same as long as the listed items remain the same.

I have been running IPv6, with SLAAC, on my home network for 12 years.  Yes, there are new privacy addresses every day.  I have seen that many, many times.  If I were to boot my desktop system today, I would have 1 persistent and 1 privacy address.  Tomorrow I would have 2 privacy addresses and so on for 7 days when the oldest one is deleted.

Setting ipv6.addr-gen-mode=0 will change it to EUI64 if you prefer that.

I have considered that.  I'll see what happens and if I get both a persistent and privacy address.

On 2022-05-11 12:56 a.m., Andrei Borzenkov wrote:

Apparently you confuse privacy and temporary addresses.

No I'm not. From https://labs.ripe.net/author/johanna_ullrich/ipv6-addresses-security-and-pri... IPv6 Privacy Extension The IPv6 Privacy Extension is defined in RFC 4941. It is a format defining temporary addresses that change in regular time intervals; successive addresses appear unrelated to each other for outsiders and are a means of protection against address correlation. Their regular change is independent from the network prefix; this way, they protect against tracking of movement as well as against temporal correlation. Privacy addresses were created because of concerns the MAC based address could be used to track a mobile device.  So yes, privacy addresses are temporary and you get a new one every day, up to 7, with the oldest discarded. Perhaps you're thinking of private addresses, which would be RFC1918 on IPv4 and Unique Local Addresses (ULA) on IPv6.

On 2022-05-11 8:54 a.m., Bengt Gördén wrote:

On 2022-05-11 14:41, James Knott wrote:

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RFC 4941

Might not have any bearing on your problem but that one is obsoleted by rfc8981.

No difference.  Start reading from section 3.1 and you'll see it describes exactly what I've been saying.

On 2022-05-11 9:04 a.m., Andrei Borzenkov wrote:

I have no idea where you got the magic number 7 from, but it is still not relevant to your original question. Your system does have a stable global non-temporary address which does not change as long as you do not change system configuration.

I can count.  I have been running IPv6 with SLAAC for 12 years. When I first boot my desktop computer, I get one persistent address, in my case based on the MAC, and 1 privacy address based on a random number.  The next day, I'll have 2 privacy addresses, then 3, then 4, then 5, then 6, then 7.  The next day I will still have 7 privacy addresses, but what had been the oldest the day before has been discarded. Here are my current ULA addresses, but the same applies to my global addresses:

ifconfig|grep fd48         inet6 fd48:1a37:2160:0:f932:70a1:d12e:9eb2  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:c95e:fa9:3a87:9fe3  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:c538:d337:2c53:7d58  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:6d1a:c696:6f61:f1e7  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:59d:f82:d976:9ba0  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:76d4:35ff:fe5b:f5fa  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:f55b:d2e7:78ca:3281  prefixlen 64 scopeid 0x0<global>         inet6 fd48:1a37:2160:0:95fe:dc25:c2d7:a2e5  prefixlen 64 scopeid 0x0<global>

Unless I need new glasses, there are 8 listed, one of which is based on the MAC address.  Tormorrow, there will still be 8, with one new one and the oldest discarded.  This is the way it's been working for 12 years.