I have disabled WAN1 (ADSL) and just use WAN2 Ethernet where my IP address is issued dynamically by my ISP (Virgin) and that also presets the DNS servers . If I alter the DNS servers IP to some other that I wish to use then they get overwritten back to Virgin's when the router reboots. I mostly use static addresses on my PC's and they point to the 2820VN as their DNS server.

This outdated technical FAQ exactly addresses the matter and indicates how to change this behaviour (option 1 at the bottom) and override the DNS servers that the router uses but this Telnet command (IP DNS x.x.x.x y.y.y.y) is not present on the 2820VN.
http://www.draytek.co.uk/support/kb_vigor_dns.html

So how can I change this ?

Is there documentation available on the Telnet commands for the 2820 series ?

Set then under LAN - General Setup - LAN1 - DNS primary & secondary addresses. - that will make DHCP give out those addresses for DNS.

If you want the router to use them for instance if you're using the router as a DNS forwarder address then tick Force DNS manual setting to make the router use those IPs as well.

Ahh great - I kinda expected this to be a WAN rather than LAN option ...

Many thanks

Voodle wrote: Set then under LAN - General Setup - LAN1 - DNS primary & secondary addresses. - that will make DHCP give out those addresses for DNS.

If you want the router to use them for instance if you're using the router as a DNS forwarder address then tick Force DNS manual setting to make the router use those IPs as well.

Many thanks for this post Voodle, I have been struggling to get my Vigor 2820 to use my specified DNS server rather than my ISP one for ages. The DNS always reverted to my ISP one as soon as the internet connection was made. I was setting this in the WAN setup and didn't think it would be in LAN setup.

See below:


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Hi

I think I'm now using both ISP allocated DNS servers, the Draytek DNS cache service and a third party public DNS as my PC's 'secondary' one. I'd be very interested to hear any forum users feedback (or Draytek feedback) on the below strategy, as assuming there are no unforeseen problems, it would seem a pretty good setup to use:

I used the DNS Benchmarking tool to identify an alternative to my ISP assigned DNS servers (90.207.238.97 and 90.207.238.97). I found a good one (for my location), but for the below example, I'll just use one of the open ones that folks all know 208.67.220.220. I initially set the LAN side 'DNS Server IP Address' (in the red outlined box shown in the above post) with one of my ISP's DNS as primary and the alternative as secondary. Looking at the WAN side 'Online Status' section in my Draytek, it shows still indicates the two ISP defaults as shown below:

LAN Status Primary DNS: 90.207.238.97 Secondary DNS: 90.207.238.99

But looking at the PC's the DHCP settings are allocated using two DNS servers as set in the LAN side. This can be seen from the below 'ipconfig /all' stats (Win XP SP3):

Default Gateway . . . . . . . . . : 192.168.96.1
DHCP Server . . . . . . . . . . . : 192.168.96.1
DNS Servers . . . . . . . . . . . : 90.207.238.97
208.67.220.220

My current configuration is a little different from that in that I have left the top one (set in that same LAN side DNS box) completely blank, and I've only populated the secondary IP address field with my alternative DNS server (and, as before, I have not ticked the force button). This is quite interesting as the ipconfig /all now shows the below results.

Default Gateway . . . . . . . . . : 192.168.96.1
DHCP Server . . . . . . . . . . . : 192.168.96.1
DNS Servers . . . . . . . . . . . : 192.168.96.1
208.67.220.220

My thinking is that the above setting will thus means the PC uses the two ISP choices along with its internal DNS cache as primary, and in addition to that, it also has the alternative DNS (208.67.220.220) as a secondary; that would seem to be providing a very good DNS setup, so I'd be interested in any thoughts on that configuration.

Bri

PS I have looked at the Draytek documentation on where to set DNS and it looks like it might be referring to ancient firmware. It does suggest that you can set the DNS on the WAN side (under 'Internet Access' settings) but there is only an option to do that for MPoA (RFC1483/2684) and not under PPPoE / PPPoA. It would seem that the only way to get the WAN side to display the DNS you choose is to tick that 'Force DNS manual setting' on the LAN side (and that would also stop it caching DNS's in the Draytek). I think the documentation is a little wanting in that it really needs to be updated to show how to manipulate DNS in current device firmwares.