DNS settings on smartrg router

[bernaluser]

Yesterday when the DNS was causing problems, I changed the DNS settings on the SmartRG router 515ac to use both

Obtain IPv6 DNS info from a WAN interface:
Wan interface selected ipoe_eth4/eth4.1

and

Use the following Static DNS IP address:
Primary DNS Server: 8.8.8.8
Secondary DNS Server: 8.8.4.4

I am wondering if its ok to use both of these and which one the SmartRG will use as the primary DNS (I can't find any information on the web about this).

[aaronchang]

Unless you have manually enabled IPv6 on your home devices, it's not going to be used on your network and you don't need to worry about the option that you enabled.
But let's say you did enable it on your computer, then it will connect via IPv6 DNS only, which Sonic supports since 2003.

As for the IPv4 DNS, your router will always contact the Primary to resolve addresses (ie. websites). If the Primary is ever down then the Secondary will be used.

And to avoid confusion as to how your modem/router can connect to both IPv4 and IPv6, currently ISPs support a method called "dual-stacking" in order for them to work side by side.

You can test if you are using IPv6 by going to this site from each device http://test-ipv6.com/