Turn off Auto Configuration for IPV6 Merlin RT-AC66U

[mbze430]

Is there a way to either turn off the autoconfiguration via the GUI or CLI in the Asus/Merlin firmware? I am using 376.49_5

I am on TWC and Native settings gives me the IPV6 addresses from TWC. However the "auto configuration" is totally screwing up my internal network. I have Win2k12 R2 DC that is already running DNS and DHCPv4&v6. But with the "auto configuration" on the ASUS router being on, it picks up and uses the router's settings

I have set the DHCPv6 turned OFF on the ASUS.

I know it's the ASUS because every time I change between stateless and stateful (while DHCPv6 is off on the router) the IP address on my machine change with ever state it is on the ASUS... plus on the DC running DHCPv6 it doesn't lease out.

If I turn off IPV6 completely on the ASUS, then my DC lease out, but then it won't communicate out in to the WAN side.

Please help!!

 

[mbze430]

After some more testing and messing around. It's the RA that is giving out stateful information to all the host. Which is fine IF the DNS setting would play nice.

I don't know if this is a bug or not in the ASUS firmware. If I enable RA and set "Connect to DNS Server automatically" to Disable. And put in my DC's DNS IPV6 address, it will not advertise that address to the clients. it will always put the IPV6 LAN's address as the DNS.

This is what its killing me not able to authenticate with the DC. Because it can't never find the DC's DNS.

Is there a way manually edit the RA's advertisement of the DNS via the CLI?

If I manually go to each client and manually input the IPV6 DNS then it works perfectly and ipv6-test.com passes all test. However... I have over 25+ workstations, I rather not have to manually do that. And they range from Win7-Win8.1 to Ubuntu and other Linux boxes

 

[PabloAbonia]

I will leave if you use the dnsmasq.postconf on Merlins firmware, you can comment out enable-ra to prevent router announcements. However, isn't there a "router advertisement" that can be set on the IPv6 page?




--
Pablo

 

[mbze430]

Yes I can turn off RA completely off. But then I couldn't get my DC to route IPV6 traffic. I was using this guide, but I couldn't get it to work

http://rakhesh.com/windows/enabling-ipv6-router-advertisements-on-windows/

Either way, the ASUS Firmware seems to have a bug for RA not passing the DNS information, I believe. RA only pass IPV6 LAN address as DNS even if you give a different DNS in the menu/gui.

 

[PabloAbonia]

Then you would want to enable-ra in dnsmas.conf, and then use dhcp-option6:23,[PUTV6ADDRESSHERE]. I would suggest checking the dnsmasq manual page at

http://www.thekelleys.org.uk/dnsmasq/docs/dnsmasq-man.html



--
Pablo

 

[m00ster]

Windows server configuration for static ipv6 addresses

Hello,

when running a windows server utilizing ipv6 and you want it to have a static ip address and not use dynamically generated stateless addresses on the subnet then do the following:

Find the Interface you wish to modify:

netsh interface ipv6 show interface

disable routerdiscovery on the interface(where NUM is the id of the interface from the command above):

netsh interface ipv6 set interface NUM routerdiscovery=disabled

enable managed address configuration for said interface:

netsh interface ipv6 set interface NUM managedaddress=enabled

enable otherstateful configuration to get non address configuration from radvd such as domain search order:

netsh interface ipv6 set interface NUM otherstateful=enabled

You may want to disable teredo and isatap on servers as well.

netsh interface teredo set state=disabled
netsh interface isatap set state=disabled

This configuration will allow your windows server to have statically assigned addresses for services such as DHCP while not needing you to modify the radvd configuration for the subnet. Ensure that you have a static ipv6 address configured for the interface as well as a statically assigned gateway(without RADVD you may need to find the link local address or use the global address on the interface of your ipv6 router connected to your local subnet). Do this for all servers with a static IPv6 address. Why Ms doesn't do this auto when assigning static addresses to a interface is beyond me.

-jon

 

[OCedHrt]

I have DHCP6 on the router running fine in conjunction with my DC giving out DHCP6 addresses.

There is definitely some configuration you need to do on the DC. It's actually fine for the router to do RA as this propogates the ISP's IP6 addresses and it's own link-local IP6 address as the default gateway to your internal devices, allowing them to then route to the router. If you turn off RA, you will likely have to set the default gateway manually on the DHCPv6 server.

Edit: It seems you can turn off DHCPv6 on the router, but leave on RA. I'm not sure if this still allows RA to work.

You don't need to set "otherstateful=enabled" on the DC unless you want it to pick up the DNS from the router's DHCPv6 server. Since the DC is running it's own DNS, you probably don't want to do this. You can import your ISP's DNS into your DC's DNS.

Rather, you only need to enable advertise and managed on your DHCPv6 server. They can be combined into one command. I use persistent store so it doesn't need to be set again when the server reboots.

netsh int ipv6 set int <int #> advertise=enable managed=enable store=persistent

Disclaimer: I am speculating on this next part, as I don't remember why I needed to set this, but there was definitely some issue that needed to be resolved.

After running the above command, you will get your own IP6 addresses on capable devices. And if RA on the router is on, you will find that they can get online still.

However, they cannot ping each other, nor the DC. This is because there is no route to your DC published to the devices so they end up going to the gateway, which doesn't know what to do with your own internal IP6 prefix.

netsh int ipv6 set route prefix=<internal ipv6 prefix>::/64 <int #> publish=yes store=persistent

I have a route on the DHCP server that is prefix::/128, and I'm assuming this is from the DHCP scope.

 

[ThinSTAR]

Did you manage to get this working?
I'm running into the same issue, and have FW 380.65, I have set my clients ipv6 DNS manually.

 

[XSXS]

What's the correct set up for ipv6?