Update - now IPv6 adress on interface

[suse_rasputin]

PPPS:

I still have no idea, where these IPv6 addresses come from. Self generated?

The router/firewall shows me

“The DHCPv6 Server can only be enabled on interfaces configured with a static IPv6 address. This system has none.”

…so pretty sure it’s not the router/firewall.

[tsu2]

@suse_rasputin

Hi!

Don’t get it wrong, but: explanations like “the system nowadays” are nonsense. Some human has decided to give the interfaces IPv6 and normally the interfaces start to send bradcast trash on IPv6 trough my network (and if the router doesn’t block them, they will send each and everything wherever they want.

Plainly: It’s a security issue to have interface sending stuff around without control by the user. Nobody need paternalistic decisions “by the system” to increase the attack surface of his systems.

Please tell me how to disable this in networkmanager (without fiddeling any config files, which will be renewed with every TW update, as for the networkmanager connectivity check, another security issue present in TW, but not in 13.2).

Many thanks in advance.

Read up about IPv6.
One of its features is to eliminate network broadcasts, everything is a directed network connection.
There are usually 2 self-generated IPv6 addresses, one is scoped to be usable only in your logical LAN, the other might communicate further(It contains the prefix obtained from the upstream router).

If you want to disable IPv6, the methods described in this article should work in TW as well

How to disable autoconfiguration on IPv6 in Linux?

TSU

[nrickert]

@suse_rasputin

PPS: Tried to change these settings in the NetworkManager of a 42.3, there I get asked for the root password to change the interfaces IPv6 settings.

Is this a bug in TW? Maybe?

It’s a bug in the NetworkManager applet (“nm-plasma5” or something similar), and is supposedly fixed upstream. I had forgotten about that.

When you first try to edit the connection (I think it is the “wired” tab, there’s a box for auto-negotiation. Check that box, and then you should be able to save changes. And the checking of that box will be one of the changes that you save.

[tannington]

@suse_rasputin

PPS: Tried to change these settings in the NetworkManager of a 42.3, there I get asked for the root password to change the interfaces IPv6 settings.

Is this a bug in TW? Maybe?

FWIW I don’t believe it’s a bug. I’ve just tried changing this on a TW system (20170928) without any problem.

Upon first opening the IPv6 tab “Apply” is greyed out, but as soon as a (different) selection is made from the “Method” drop-down box then “Apply” becomes active.

If set to “Ignored”, then after a reboot there is no IPv6 address.

paul@Orion-15:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether [redacted] brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.3/24 brd 192.168.0.255 scope global dynamic enp2s0
       valid_lft 86208sec preferred_lft 86208sec
paul@Orion-15:~$

Edit: Whilst I was trying this “nrickert” posted, I already had “Auto-Negotiation” checked. So I guess the “bug” wasn’t apparent to me.

[suse_rasputin]

…Thank you so much, nrickert. Problem solved. party

When will the bug be fixed?

[arvidjaar]

@nrickert

There’s a configuration file “/etc/NetworkManager.conf”. But I don’t know if there is a setting to disable IPv6. I did not see on while browsing the man page.

This file controls global NM behavior. IPv6 is per-connection setting.

[suse_rasputin]

…in Fedora this has apparently been fixed some time ago. Alternative to “Allow Auto-negotiation” the Speed and Duplex can be entered manually, then the IPv6 settings (or anything else) can be changed AND saved.

[Fraser_Bell]

@nrickert

There’s a configuration file “/etc/NetworkManager.conf”. But I don’t know if there is a setting to disable IPv6. I did not see on while browsing the man page.

There is a connection specific setting. You have to go into connection settings (right click on the NetworkManager icon). And then edit the connection that you are using.

There’s a tab for ipv6. You may have to maximize the connection editor, or scroll right, in order to see that tab.

On that tab, there’s a box for “Method”. It defaults to “Automatic”. Changing to “ignored” will probably disable ipv6. Maybe the change doesn’t take effect until reboot.

Just tested: I changed that setting on my machine, disconnected the wireless (do not know if that is necessary, but), reconnected wireless and the change took effect immediately.

[suse_rasputin]

Fresh install of TW 64bit KDE last weekend. Using NetworkManage, disabled IPv6 in the taskbar applet by setting IPv6 to “Ignored” (and in the Yast Network Settings IPv6 is unchecked).

After updates half an hour ago I suddenly saw an IPv6 address on the LAN Interface. Unbelievable.

Switching the interface to Wicked and back to NetworkManager -> IPv6 address is gone. How can it be?

[tsu2]

@suse_rasputin

Fresh install of TW 64bit KDE last weekend. Using NetworkManage, disabled IPv6 in the taskbar applet by setting IPv6 to “Ignored” (and in the Yast Network Settings IPv6 is unchecked).

After updates half an hour ago I suddenly saw an IPv6 address on the LAN Interface. Unbelievable.

Switching the interface to Wicked and back to NetworkManager -> IPv6 address is gone. How can it be?

You probably received some kind of update that “re-made” the network device, and the default likely was to support IPv6… Although I could say that whether IPv6 is enabled or not is a matter of choice, there are probably very few scenarios where IPv6 should be disabled altogether. hence the default configuration… A self-generated local address might be useful in some situations and shouldn’t be some kind of security issue because it shouldn’t be able to work beyond the LAN.

Your act of switching to Wicked and back again probably re-enabled your User settings by restarting your network service. You could probably have accomplished the same thing by

systemctl restart network

TSU

[suse_rasputin]

Yeah, but “fun” fact is: I get an IPv6 adress on the interface after EVERY reboot now, as long as NetworkManager is enabled. Would have to switch to Wicked and back after every reboot now.

With Wicked enabled I don’t get an IPv6 address. That’s no fun!

[tannington]

@suse_rasputin

Yeah, but “fun” fact is: I get an IPv6 adress on the interface after EVERY reboot now, as long as NetworkManager is enabled. Would have to switch to Wicked and back after every reboot now.

Not seeing that behaviour here on TW 20171025 (using NetworkManager with IPv6 set to “Ignored”)

http://paste.opensuse.org/view/raw/6da8b8a5

[suse_rasputin]

…up to now I have this IPv6 address only on one machine (rest is under way), fresh installed with TW20171019 full DVD last weekend after updating yesterday. No applications installed, no special repos. This NetworkManager has its own life, apparently.

What I see on all machines is an IBus icon in the taskbar, with most machines switched to EN keyboard layout…

[tannington]

@suse_rasputin

This NetworkManager has its own life, apparently.

>:)

What I see on all machines is an IBus icon in the taskbar, with most machines switched to EN keyboard layout…

You’re not alone it would seem. [opensuse] IBus icon after upgrading to TW 20171023? - openSUSE Users - openSUSE Mailing Lists

I’ve had ibus uninstalled for quite a while (can’t remember why)… so I’m not seeing that either.

[nrickert]

@suse_rasputin

Yeah, but “fun” fact is: I get an IPv6 adress on the interface after EVERY reboot now, as long as NetworkManager is enabled.

Go into NetworkManager, “Edit connections”. There’s a setting for enable/disable IPv6. However, you will have to do that for every connection – but just once, not every reboot. For the wired (ethernet) connection, that will require the root password.

[suse_rasputin]

It’s already set to “Ignored” for IPv6, from first day. And in Yast-> Network Settings IPv6 is turned off, too. And the interface configured for DHCP IPv4-only.

No additional option to turn IPv6 off…