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The Graveyard - Products No Longer Supported => Routers / COVR => DIR-850L => Topic started by: datagramm on April 17, 2018, 01:28:57 PM

Title: IPv6 trouble
Post by: datagramm on April 17, 2018, 01:28:57 PM
Hi!

My provider uses IPv6 with "Auto Configuration (SLAAC/DHCPv6)". Indeed, my DIR-850L B1 gets an IPv6 WAN Address (even if this is not very stable and I have to reboot a lot) but the router itself doesn't hand the IPv6 over to my computers (macOS 10.13.4 and Windows 10), thus I don't get IPv6 connectivity. I tried firmware 2.21B01 and 2.22B02.

What could be wrong?
Title: Re: IPv6 trouble
Post by: GreenBay42 on April 17, 2018, 01:49:44 PM
By default the router should pass through IPv6 addresses to your devices that support it. Do other devices other than the 2 computers get an IPv6 address?

On the Windows computer make sure IPv6 is enabled. (windows key + R, type in ncpa.cpl, right-click your adapter and select properties). Make sure there is a check next to IPv6 and it is set to DHCP.

On the Settings > Internet > IPv6 page, what settings are enabled?



Title: Re: IPv6 trouble
Post by: datagramm on April 17, 2018, 02:01:08 PM
I made a little experiment: I disabled DHCP-PD and entered a fake LAN IPv6 Address. Immediately both computers got an IPv6 address from the router. But of course there won't be working connectivity with a fake LAN address. So yes, IPv6 is enabled on both machines, but the router seems not to be able to complete the necessary auto configuration based on the WAN address.
Title: Re: IPv6 trouble
Post by: GreenBay42 on April 17, 2018, 02:05:51 PM
Under LAN IPv6 Address Settings, (with Enable DHCP-PD enabled), click Advanced Settings.

Enable Automatic IPv6... and Enable Automatic DHCP-PD in LAN should both be enabled.

What is your autoconnection Type set to?
Title: Re: IPv6 trouble
Post by: datagramm on April 17, 2018, 02:23:23 PM
Enable Automatic IPv6... and Enable Automatic DHCP-PD in LAN should both be enabled.

They are indeed both enabled.

I tried all 3 autoconnection types: SLAAC+RDNSS, SLAAC+Staless DHCP and Stateful DHCPv6. No one works.
Title: Re: IPv6 trouble
Post by: FurryNutz on April 17, 2018, 02:30:39 PM
Who is the ISP?

What is the Mfr and model# of the ISP modem your using with the 850L?

Title: Re: IPv6 trouble
Post by: datagramm on April 17, 2018, 02:43:02 PM
The ISP is t-2.net. They provided me with a MiLAN Technology MIL-SM801G Managed 8 Port 10/100BASE-TX + 1000BASE-FX. It's an FTTH connection. If I connect my laptop over ethernet directly to their device everything works fine.
(http://usersmanuals1.com/uhfiles/322/489969/mil-sm801g-manuals-1_2.png)
Title: Re: IPv6 trouble
Post by: FurryNutz on April 17, 2018, 02:48:30 PM
You may not need the DIR router then. Something to try, turn the DIR router in to a LAN to LAN wireless AP:
Turning a router into an AP. (http://forums.dlink.com/index.php?topic=40856.0)

See if this works in this configuration...if it does, then you can keep this configuration. You can always change back.
Title: Re: IPv6 trouble
Post by: GreenBay42 on April 17, 2018, 02:53:36 PM
If you connect both computers via Ethernet directly to the MIL switch do they both get valid addresses?

Are ALL your local devices getting IPv6 or will you have IPv4?  Are you using the router for wireless connectivity only?
Title: Re: IPv6 trouble
Post by: datagramm on April 17, 2018, 03:22:05 PM
When I connect both directly over ethernet to the MiLAN I get:
macOS: valid IPv4 and IPv6
Win10: IPv6 only (funny, isn't it?)

I'm using the DIR-850L B1 for Wi-Fi and as a router for my printer as well as my IP-phone. I might try turning the DIR into a switch, but I'm not sure, if my printer will work. On Win10 I'll have to fix the missing IPv4, when connected directly to the MiLAN …  :D

The phone and the printer are still IPv4-only devices.
Title: Re: IPv6 trouble
Post by: FurryNutz on April 17, 2018, 03:43:41 PM
Seems like your MiLan switch may be a routing and DHCP server as well. It is a managed switch. So you might be in a double NAT condition which isn't recommended. This will cause problems like this with IPv6.
Link>Double NAT (http://www.practicallynetworked.com/networking/fixing_double_nat.htm) and How NAT Works (http://computer.howstuffworks.com/nat.htm).

Is there any other modem or ONT device before this switch?

Try the 850L in LAN to LAN AP mode. This will act as a pass thru for IP address and internet traffic while providing wifi access as well. Think of it as adding wifi to the MiLan router since it doesn't have wifi support. This should work well.

Title: Re: IPv6 trouble
Post by: datagramm on April 17, 2018, 04:05:38 PM
As the MiLAN switch is owned by ma ISP I can't check what it actually does. This means also that I don't know if there is a firewall running on it. It might assign a public IP without a firewall to my printer …
Title: Re: IPv6 trouble
Post by: FurryNutz on April 17, 2018, 04:10:56 PM
Let us know what happens if you change the DIR router in to a AP.
Title: Re: IPv6 trouble
Post by: datagramm on April 18, 2018, 12:11:01 PM
I got some additional information from my provider about their DCHP and IP address policies:

Every subscription gets 2 public IPv4 addresses and an unlimited number of IPv6 addresses. Their DHCP lease time is 24 hours and there is no NAT on their side. Thus turning the DIR into a wireless switch and attaching it to the MiLAN switch wont give a usable result for IPv4 because there must be a NAT routing device in between.
Title: Re: IPv6 trouble
Post by: FurryNutz on April 18, 2018, 12:18:38 PM
Ok, thanks for this information. Helps to clarify this issue.

I recommend that you phone contact your regional D-Link support office and ask for help and information regarding this. This maybe a FW issue that we can't resolve here in the forums. We find that phone contact has better immediate results over using email.
Let us know how it goes please.