-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 El 2023-05-09 a las 14:12 +0200, Per Jessen escribió:
Carlos E. R. wrote:
On 2023-05-09 08:30, Per Jessen wrote:
ff02::1 is a multicast address meaning "All Nodes". Fyi, ff00::/8 are all multicast addresses. The Ethereal output even explains it in plain text "Router Advertisement from cc:ed:dc:05:80:d4". I think I remember cc:ed:dc:05:80:d4 being your router. (cc:ed:dc = Mitrastar).
Ok, so the address is not an address, but it signals what it is.
It is an address, a multicast address. Much like a broadcast or multicast IPv4 address. There are other multicast addresses that are dedicated for specific purposes, e.g. ff05::101 for ntp.
Ok.
However - I don't think an RA should cause your /etc/resolv.conf to be updated, unless the DNS also changes.
No, the address doesn't change.
So, it is normal for a router to send RA every 200 seconds?
Yes, that is quite typical I would say. It is the default in radvd.
Then it is not the router fault (yet), there is something else. Maybe Linux overreacting.
Your router is sending an RA every 10 seconds though - that is not normal, but not necessarily a problem.
Ah. 10 seconds. But Linux reacts about every minute or two. Wait, I don't really know, the timestamp of the file doesn't show seconds. Telcontar:~ # ls -l --full-time /run/wicked/leaseinfo.eth0.auto.ipv6 - -rw-r--r-- 1 root root 262 2023-05-09 14:33:31.340692040 +0200 /run/wicked/leaseinfo.eth0.auto.ipv6 Telcontar:~ # ls -l --full-time /run/wicked/leaseinfo.eth0.auto.ipv6 - -rw-r--r-- 1 root root 262 2023-05-09 14:33:31.340692040 +0200 /run/wicked/leaseinfo.eth0.auto.ipv6 Telcontar:~ # ls -l --full-time /run/wicked/leaseinfo.eth0.auto.ipv6 - -rw-r--r-- 1 root root 262 2023-05-09 14:33:36.480692009 +0200 /run/wicked/leaseinfo.eth0.auto.ipv6 Telcontar:~ # ls -l --full-time /run/wicked/leaseinfo.eth0.auto.ipv6 - -rw-r--r-- 1 root root 262 2023-05-09 14:33:41.604691979 +0200 /run/wicked/leaseinfo.eth0.auto.ipv6 Telcontar:~ # Bingo! :-(
Shouldn't Linux see that the address is the same, and do nothing?
That seems reasonable, but as we don't know the exact contents of the RA, it's not easy to say. My /etc/resolv.conf files only change when the machine is rebooted.
The DNS servers (RDNSS) and the search list (DNSSL) may be supplied in the RA, and they may have a lifetime specified. (RFC8106).
Wild guessing - when your /etc/resolv.conf changes every minute, perhaps it is because the lifetime is set incorrectly.
You could try running a tcpdump :
tcpdump -s0 -wcapturefile -n -i interface icmp6
I captured 5 packets, 3 RA. Yes, the packet contains information about the IPv6 DNS servers, route and prefix. I can mail you the 896 bytes of the capture, if you wish.
Look at the capturefile with wireshark, see what it says about the RA contents. I'm doing the same just now, I just don't get very many RAs :-)
- -- Cheers, Carlos E. R. (from openSUSE 15.4 x86_64 at Telcontar) -----BEGIN PGP SIGNATURE----- iHoEARECADoWIQQZEb51mJKK1KpcU/W1MxgcbY1H1QUCZFpAchwccm9iaW4ubGlz dGFzQHRlbGVmb25pY2EubmV0AAoJELUzGBxtjUfV0VUAoIyEnG1EP0fDeXJnJyCp cRxPNTrYAJ4zBf+k24tyWUc7jscJVCBhca8AIw== =KiwT -----END PGP SIGNATURE-----