[opensuse] Learning IPv6 the hard way? Why can I even ping or make use in general of ULA address?
Hi there, learning some IPv6 the hard way and trying to make sense of it all. Some soho/router has dualstack ipv6 and ipv4 internet connection via some XDSL ISP. The router provides some LAN with apparently partly ipv6 LAN via dhcpv6. It offers DNS information to LAN clients via dhcpv6. Some Windows7 machine retrieves an rfc1918 DNS server address via dhcpv4 and some ULA (fd00::xxxx:xxxx:xxxxx:xxxxx) DNS server ip address (its own router/gateway IPv6 address) via dhcpv6. Every now and then the WIndows7 machine stops being able to even ping that ULA address. All machines, the windows7 (multiple) and the router/gateway have additionally fe80::...... addresses (link local?) as well. I am now trying to figure out, why I can even ping and use those ULA fd00::xxxxxxxxxxx addresses to begin with, how they come about and where the mask (prefix, suffix and stuff) logic comes into the game here and why I can ping and make use of ULA at all, if all I see in routing tables and ip addresses is the fe80::xxxx addresses. I have a linux client on this LAN as well, some leap 42.2 box, and this machine has also only the fe80::xxxxxxxxx addresses as well assigned to itself and this machien never stopped being able to access the ULA address of that router/gateway and use it for DNS queries while at the same time windows trying to access that ULA address simply stopped working :( On the linux machine, /sbin/ip -f inet6 neigh doesnt yield any entries for any fd00::.... addresses and according to my scarce knowledge about ipv6 i dont see why the ipv6 stack is even able to make use of and to know what to do with fd00:: addresses at all? Any pointers and takers on this matter? TIA. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
cagsm wrote:
Hi there,
learning some IPv6 the hard way and trying to make sense of it all.
Some soho/router has dualstack ipv6 and ipv4 internet connection via some XDSL ISP. The router provides some LAN with apparently partly ipv6 LAN via dhcpv6. It offers DNS information to LAN clients via dhcpv6.
Sounds good. What does "partly" mean here?
All machines, the windows7 (multiple) and the router/gateway have additionally fe80::...... addresses (link local?) as well.
Yes, that is required.
On the linux machine, /sbin/ip -f inet6 neigh doesnt yield any entries for any fd00::.... addresses and according to my scarce knowledge about ipv6 i dont see why the ipv6 stack is even able to make use of and to know what to do with fd00:: addresses at all?
Any pointers and takers on this matter?
Any chance you could summarize the matter in 2-3 lines? If there is a Windows issue, you're probably on the wrong list, and I couldn't see any Linux problem? Your fd00 addresses are probably being dished out by the dhcpv6 server, but that is a bit odd. It ought to dish out from a real /64 network, allocated to you by your ISP. -- Per Jessen, Zürich (10.0°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2017-02-20 13:41, Per Jessen wrote:
cagsm wrote:
Hi there,
learning some IPv6 the hard way and trying to make sense of it all.
Some soho/router has dualstack ipv6 and ipv4 internet connection via some XDSL ISP. The router provides some LAN with apparently partly ipv6 LAN via dhcpv6. It offers DNS information to LAN clients via dhcpv6.
Sounds good. What does "partly" mean here?
All machines, the windows7 (multiple) and the router/gateway have additionally fe80::...... addresses (link local?) as well.
Yes, that is required.
On the linux machine, /sbin/ip -f inet6 neigh doesnt yield any entries for any fd00::.... addresses and according to my scarce knowledge about ipv6 i dont see why the ipv6 stack is even able to make use of and to know what to do with fd00:: addresses at all?
Any pointers and takers on this matter?
Any chance you could summarize the matter in 2-3 lines? If there is a Windows issue, you're probably on the wrong list, and I couldn't see any Linux problem? Your fd00 addresses are probably being dished out by the dhcpv6 server, but that is a bit odd. It ought to dish out from a real /64 network, allocated to you by your ISP.
Windows has its own system for getting IPv6 even on IPv4 networks, behind your back. https://en.wikipedia.org/wiki/Teredo_tunneling It is used for things like sharing updates, I believe. Not sure. It is not very clear. I don't have Windows running now to guess what kind of addresses it gets. Teredo has its importance in Linux/Windows networks, because it is a network beyond the control of the network admin. -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" (Minas Tirith))
Carlos E. R. wrote:
On 2017-02-20 13:41, Per Jessen wrote:
cagsm wrote:
Hi there,
learning some IPv6 the hard way and trying to make sense of it all.
Some soho/router has dualstack ipv6 and ipv4 internet connection via some XDSL ISP. The router provides some LAN with apparently partly ipv6 LAN via dhcpv6. It offers DNS information to LAN clients via dhcpv6.
Sounds good. What does "partly" mean here?
All machines, the windows7 (multiple) and the router/gateway have additionally fe80::...... addresses (link local?) as well.
Yes, that is required.
On the linux machine, /sbin/ip -f inet6 neigh doesnt yield any entries for any fd00::.... addresses and according to my scarce knowledge about ipv6 i dont see why the ipv6 stack is even able to make use of and to know what to do with fd00:: addresses at all?
Any pointers and takers on this matter?
Any chance you could summarize the matter in 2-3 lines? If there is a Windows issue, you're probably on the wrong list, and I couldn't see any Linux problem? Your fd00 addresses are probably being dished out by the dhcpv6 server, but that is a bit odd. It ought to dish out from a real /64 network, allocated to you by your ISP.
Windows has its own system for getting IPv6 even on IPv4 networks, behind your back.
Long disabled on our two remaining Windows machines. Anyway, a Windows IPv6 issue is surely off-topic. -- Per Jessen, Zürich (9.5°C) http://www.cloudsuisse.com/ - your owncloud, hosted in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 2017-02-20 17:32, Per Jessen wrote:
Carlos E. R. wrote:
Windows has its own system for getting IPv6 even on IPv4 networks, behind your back.
Long disabled on our two remaining Windows machines. Anyway, a Windows IPv6 issue is surely off-topic.
Teredo punches a hole in your Linux firewall ;-P -- Cheers / Saludos, Carlos E. R. (from 42.2 x86_64 "Malachite" (Minas Tirith))
On Mon, Feb 20, 2017 at 5:32 PM, Per Jessen <per@computer.org> wrote:
Long disabled on our two remaining Windows machines. Anyway, a Windows IPv6 issue is surely off-topic.
but it is not really off topic as I am tring to figure out why ULA addresses work or how they work and who is in charge of their routing and scope/visibility in the linux kernel. As I wrote before, sure the windows dies down on ULA fd00::addresses every now and then, but the soho router has that address and the linux machine continues to be able to make use of it. Only the linux itself doesnt show or display an fd00::..... of its own via ifconfig nor ip or such commands and thats why I wanted to learn about it why and how ula works on opensuse or the linux kernel in general to be able to hunt down this bug. TIA. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 02/20/2017 12:23 PM, cagsm wrote:
but it is not really off topic as I am tring to figure out why ULA addresses work or how they work and who is in charge of their routing and scope/visibility in the linux kernel.
The ULA addresses are the IPv6 equivalent of the IPv4 RFC1918 addresses. As for routing, it works the same for any IPv6 address, other than link-local, which are not routable. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
cagsm wrote:
but it is not really off topic as I am tring to figure out why ULA addresses work or how they work and who is in charge of their routing and scope/visibility in the linux kernel. As I wrote before, sure the windows dies down on ULA fd00::addresses every now and then, but the soho router has that address and the linux machine continues to be able to make use of it.
As James wrote yesterday, it's a fairly normal address, it works the same other addresses do. I find it odd that your router is configured to use it - I would expect your router to be given a /64 prefix by your ISP, and then dish out addresses from that. However, dishing out addresses from a random fd00 prefix is equally valid.
Only the linux itself doesnt show or display an fd00::..... of its own via ifconfig nor ip or such commands and thats why I wanted to learn
Okay, if 'ip addr' does not show a fd00 address, your interface was not assigned a fd00 address. I presume it has an ipv4 address, and an ipv6 link-local (fd80). -- Per Jessen, Zürich (7.8°C) http://www.hostsuisse.com/ - virtual servers, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 02/21/2017 02:34 AM, Per Jessen wrote:
I would expect your router to be given a /64 prefix by your ISP, and then dish out addresses from that. However, dishing out addresses from a random fd00 prefix is equally valid.
However, a router should not be handing out those addresses for use over the Internet. Unique local addresses, like RFC1918, are not allowed on the Internet. They are for internal use only. The various address types have different scopes. Link-local are on the local network only and do not pass through a router. Unique local and RFC1918 can pass through a router, but not to the Internet and global addresses are used on the Internet. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
On 02/20/2017 07:41 AM, Per Jessen wrote:
Your fd00 addresses are probably being dished out by the dhcpv6 server, but that is a bit odd. It ought to dish out from a real /64 network, allocated to you by your ISP.
That's part of the unique local address block, which a DHCP server might be configured for, just as one could hand out addresses for the RFC1918 IPv4 addresses. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
James Knott wrote:
On 02/20/2017 07:41 AM, Per Jessen wrote:
Your fd00 addresses are probably being dished out by the dhcpv6 server, but that is a bit odd. It ought to dish out from a real /64 network, allocated to you by your ISP.
That's part of the unique local address block, which a DHCP server might be configured for, just as one could hand out addresses for the RFC1918 IPv4 addresses.
Thanks, I am well aware of what it is. It is still an odd configuration for a CPE router. -- Per Jessen, Zürich (9.5°C) http://www.hostsuisse.com/ - dedicated server rental in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org
participants (4)
-
cagsm -
Carlos E. R. -
James Knott -
Per Jessen