On Mon, 2019-06-24 at 08:52 +0200, Beniamino Galvani via networkmanager-list wrote:
Hi,
Hi Beniamino,
I checked again the log you sent and I see the problem now. When NM receives a RA, it checks whether the parameters
Which parameters exactly? Because I might be able to shed some light on this now that this is known.
changed compared to the previous RA and if so it applies the new configuration. When it does so, it also reapplies the token; this triggers a new router solicitation from kernel due to: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/ipv6/addrconf.c?h=v3.10#n4336
Interesting.
The new RA received is:
neighbor discovery configuration changed [R]:
dhcp-level none
gateway fe80::6eb0:ceff:fef5:1e4a pref high exp 1799.2317
address 2001:123:ab:123::2 exp permanent
route 2001:123:ab:123::/64 via fe80::6eb0:ceff:fef5:1e4a pref
high exp permanent
dns_server fd31:aeb1:48df::2 exp 7199.2317
Note the "changed [R]" part which means that routes changed. This is
strange because according to log there was no change from previous
RA. This causes the reapply of token, a new RS, a RA and so on ...
Here is what an RA from my router looks like:
Soliciting ff02::2 (ff02::2) on enp2s0...
Hop limit : 64 ( 0x40)
Stateful address conf. : No
Stateful other conf. : No
Mobile home agent : No
Router preference : medium
Neighbor discovery proxy : No
Router lifetime : 1800 (0x00000708) seconds
Reachable time : unspecified (0x00000000)
Retransmit time : unspecified (0x00000000)
Source link-layer address: 6C:B0:CE:F5:1E:4A
MTU : 1280 bytes (valid)
Prefix : fd31:aeb1:48df::/64
On-link : Yes
Autonomous address conf.: Yes
Valid time : infinite (0xffffffff)
Pref. time : infinite (0xffffffff)
Recursive DNS server : fd31:aeb1:48df::2
DNS server lifetime : 6000 (0x00001770) seconds
from fe80::6eb0:ceff:fef5:1e4a
Hop limit : 64 ( 0x40)
Stateful address conf. : No
Stateful other conf. : No
Mobile home agent : No
Router preference : medium
Neighbor discovery proxy : No
Router lifetime : 1800 (0x00000708) seconds
Reachable time : unspecified (0x00000000)
Retransmit time : unspecified (0x00000000)
Source link-layer address: 6C:B0:CE:F5:1E:4A
MTU : 1280 bytes (valid)
Prefix : 2001:123:ab:123::/64
On-link : Yes
Autonomous address conf.: Yes
Valid time : infinite (0xffffffff)
Pref. time : infinite (0xffffffff)
Recursive DNS server : fd31:aeb1:48df::2
DNS server lifetime : 6000 (0x00001770) seconds
from fe80::6eb0:ceff:fef5:1e4a
But three things that the above is not saying:
1. Until yesterday, the Router Lifetime of one of those RAs was 0 and
the other was 1800 (I don't recall which was which).
2. Until the last week or two, the first prefix was being advertised
with a Router preference of high and the other was medium.
3. Each of those two RAs come in two different packets, one for each
prefix rather than them both being in the same RA which I think is
the typical behaviour.
Apart from this, I think NM should not apply the token when it's already set;
That seems reasonable. Cheers, b.
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