RT-AC68U LAN DHCP DNS only one address

[BroadviewTech]

Wondering if I SSH in to the router if there's a .config file that I can add an additional DNS server address so that the system will hand out two DNS servers to the LAN DHCP clients for some redundancy?

I found /etc/dnsmasq.conf had this in it (its only private addresses so I left them in)

dhcp-range=lan,192.168.100.10,192.168.100.253,255.255.255.0,86400s
dhcp-option=lan,3,192.168.100.254
dhcp-option=lan,6,192.168.100.4,0.0.0.0
dhcp-option=lan,15,companyname.internal
dhcp-option=lan,44,208.67.222.222,192.168.100.4
dhcp-option=lan,252,"\n"

It appears to me that I may be able to change he option=lan,6,192.168.100.4,0.0.0.0 and add a public DNS?
Does that seem to be the right config file and line to change? I can't just change and test because this is a production environment. So I was hoping someone from support would be hanging around and see this. Ha ha.

 

[BroadviewTech]

I think I found my own answer here:
https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol
it shows option 44 is NetBIOS over TCP/IP Name Server

Option 6 is Available DNS servers. So I added the public OpenDNS server IP to that one and removed the 100.4 from the Option 44 line.

Can't reboot yet to test until users are gone.

 

[sfx2000]

Keep in mind that most Router/AP's these days do DNS proxy, so adding the DNS hosts won't reflect in the client leases... you'll see the router address instead on the client for IPv4 DNS (and perhaps for IPv6)

 

[BroadviewTech]

I think I'd rather hear it straight from the DNS horse's mouth and enter the public IP of the real DNS server. That way there would be less lag/compute time I'd guess. I'm assuming these devices don't do caching.

 

[sfx2000]

I think I'd rather hear it straight from the DNS horse's mouth and enter the public IP of the real DNS server. That way there would be less lag/compute time I'd guess. I'm assuming these devices don't do caching.

DNSMasq is a caching DNS server, so lookups for sites that are in the cache are much faster than reaching out to a DNS server...