On 16 February 2017 at 11:46, James Hogarth james.hogarth@gmail.com wrote:
On 16 February 2017 at 11:35, Alice Wonder alice@domblogger.net wrote:
On 02/16/2017 03:28 AM, James Hogarth wrote:
On 16 February 2017 at 10:42, Alice Wonder alice@domblogger.net wrote:
On 02/16/2017 02:32 AM, James Hogarth wrote:
On 16 February 2017 at 10:17, Alice Wonder alice@domblogger.net wrote:
On 02/16/2017 02:03 AM, James Hogarth wrote: > > > > On 16 February 2017 at 09:09, Alice Wonder alice@domblogger.net > wrote: >> >> >> >> On 02/16/2017 12:54 AM, Tony Mountifield wrote: >>> >>> >>> >>> >>> In article 4cbb9dc4-f063-3434-b7a1-d4d0e6581b5e@domblogger.net, >>> Alice Wonder alice@domblogger.net wrote: >>>> >>>> >>>> >>>> >>>> https://forum.linode.com/viewtopic.php?f=19&t=14570&p=72785 >>>> >>>> I can not figure out what I need to do. >>>> >>>> Apparently according to linode support, the VM is trying to grab an >>>> IPv6 >>>> address with some privacy stuff enabled by default causing it to >>>> not >>>> grab the IPv6 address that is assigned to me. >>> >>> >>> >>> >>> >>> Does the accepted answer at the following link give you any useful >>> hints? >>> >>> >>> >>> >>> >>> http://superuser.com/questions/243669/how-to-avoid-exposing-my-mac-address-w... >>> >>> Cheers >>> Tony >>> >> >> Not really - I tried >> >> net.ipv6.conf.all.use_tempaddr = 0 >> >> and it still fails to grab the proper IPv6 >> >> -=- >> >> Just in case, I did ask Linode support to verify that my hardware >> address >> is >> what it is suppose to be. Still waiting to hear on that. >> >> _______________________________________________ > > > > > > it still is key=value ... it uses the ifcfg- files (via the rh > plugin) and they are all key=value > > It would be helpful if you could paste the journal output (journalctl > -u NetworkManager) from the time period of attempting to get an > address ... > > also the nmcli conn sh <connection_name> information for the interface > along with your ifcfg- files
ifcfg-lo is the only one that exists on any of the servers - including the VMs that grab the correct IPv6 address.
from /sbin/ifconfig -a :
For a start stop using ifconfig ... it's broken at this point on linux, especially on multi ip and ipv6 scenarios
Use `ip -6 addr sh` for ipv6 specfic stuff, or just ip addr sh to see all IP address stuff regardless of family
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 178.79.185.217 netmask 255.255.255.0 broadcast 178.79.185.255 inet6 fe80::a8ad:d312:4ef4:7272 prefixlen 64 scopeid 0x20<link> inet6 2a01:7e00::825f:e564:ad53:72fc prefixlen 64 scopeid 0x0<global> ether f2:3c:91:18:8a:7e txqueuelen 1000 (Ethernet) RX packets 9903 bytes 1088621 (1.0 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 7786 bytes 1087223 (1.0 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
That hardware address - the 18:8a:7e corresponds with what the IPv6 address is suppose to be. But that's not the address it is grabbing, despite the fact that net.ipv6.conf.all.use_tempaddr = 0 is set.
I'm seriously wondering if the real issue is a mis-configured dhcp server in their London facility because nothing makes sense.
journalctl -u NetworkManager
reports no journal entries found.
So are you not using NetworkManager then? there should be some logs ...
I think the problem must be on their end.
It all was working fine until they migrated the VM because of a hardware issue, and I suspect now all the hardware address privacy stuff being the issue is barking up the wrong tree because all the reading I have done seems to indicate that with
net.ipv6.conf.all.use_tempaddr = 0
that a fake temporary hardware address would not be sent to their dhcp server when obtaining the address, but the real one, that should be fetching my assigned address.
Only if the kernel is doing SLAAC ... if other things (eg NM) are handling it directly they may act differently ... but then from the lack of logs is NM actually handling this?
Does systemctl status NetworkManager show it running and does nmcli show anything?
systemctl status NetworkManager ● NetworkManager.service - Network Manager Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled) Active: active (running) since Thu 2017-02-16 08:19:34 UTC; 2h 19min ago
- more stuff *
nmcli eth0: connected to Wired connection 1 "Red Hat Virtio network device" ethernet (virtio_net), F2:3C:91:18:8A:7E, hw, mtu 1500 ip4 default, ip6 default inet4 178.79.185.217/24 route4 178.79.187.246/32 inet6 2a01:7e00::825f:e564:ad53:72fc/64 inet6 fe80::a8ad:d312:4ef4:7272/64 route6 2a01:7e00::/64
- more stuff for other interfaces *
-=-
The output of
sysctl -a | grep net.ipv6 :
https://librelamp.com/sysctl.txt
It looks from that like it should not be hiding the real MAC address.
do nmcli conn show "Wired connection 1"
the entries of interest are:
ipv6.ip6-privacy ipv6.addr-gen-mode
man nm-settings to get what they mean _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
ipv6.ip6-privacy: -1 (unknown) ipv6.addr-gen-mode: stable-privacy
Okay so from the man page:
The permitted values are: "eui64", or "stable-privacy". If the property is set to "eui64", the addresses will be generated using the interface tokens derived from hardware address. This makes the host part of the address to stay constant, making it possible to track host's presence when it changes networks. The address changes when the interface hardware is replaced. The value of "stable-privacy" enables use of cryptographically secure hash of a secret host-specific key along with the connection identification and the network address as specified by RFC7217. This makes it impossible to use the address track host's presence, and makes the address stable when the network interface hardware is replaced.
I'm not certain (would have to go get changelogs) but I suspect this was a change at 7.3 with the rebase of NetworkManager
From what you say you want it sounds like you want eui64 - the one based entire on the current MAC - whereas the present version is using stable-privacy to avoid tracking.
Note that this is distinct and different to ip6-privacy which is concerned about the automatic generation of temporary addresses to use for outbound communication.
Okay a little more research as I'm curious when it changed from EUI64 by default ...
https://blogs.gnome.org/lkundrak/2015/12/03/networkmanager-and-privacy-in-th...
NM changed upstream to stable-privacy at 1.2 (the privacy extensions for the external connections were added at 1.0.4)
RHEL 7.2 enabled privacy extensions by default:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/htm...
But at that milestone we had NM 1.0.6
At the RHEL 7.3 release NM was rebased to 1.4.0
It was briefly referenced with this change in the 7.3 release notes but honestly it's pretty opaque ...
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/htm...
"NetworkManager now supports new device types, improved stacking of virtual devices, LLDP, stable privacy IPv6 addresses (RFC 7217), detects duplicate IPv4 addresses, and controls a host name through systemd-hostnamed. Additionally, the user can set a DHCP timeout property and DNS priorities."
Of course unless you knew what RFC 7217 was you'd have no idea this was the effect and there's no note that stable-privacy is the new default behaviour ARGH
Disappointingly it's not listed in the "Networking" part of the release notes ....
I think I'll raise the priority on my blog for the article I'm intending on the NM rebase ... there are nice things in the rebase like the arbitrary layering of teams, vlans and bridges but then there's unexpected stuff like this as well which should be made more visible.
So ... Alice if you want to configure the system with the older EUI64 behaviour then in your ifcfg file for that interface you need IPV6_ADDR_GEN_MODE=eui64 and then restart NetworkManager (or `nmcli conn reload` rather than a full service restart or `nmcli conn mod "Wired Connection 1" ipv6.addr-gen-mode eui64` to do it at the CLI without editing files and needing a connection reload).