Smart Link Backup Question

[Sharon Grady]

I have a RV042 small business router.  I have the Dual WAN setup in Smart Link Backup mode.

WAN1 is setup for ISP 1 with a static IP Address and  DNS servers specified.

WAN2 is setup for ISP 2 with a dynamic IP Addess (Obtain an IP automatically) with no DNS information entered.

If I unplug the cable for WAN1 the router switches to WAN2 fine.  The problem I am having is that DNS fails on all of my computers until the cable for WAN1 is reconnected.  If while the WAN1 is disconnected I do an ipconfig /release then ipconfig /renew on my computers, DNS lookups then function fine.  If I then plug the cable back in for WAN1 I again have to do ipconfig /release then ipconfig /renew on my computers to again have DNS function properly.

Any ideas on how this can be fixed?       

[linksysinfo · Accepted solution]

are you able to set any DNS manually on WAN2 whilst DHCP is set to dynamic?  Try adding DNS entries from OpenDNS Servers

208.67.222.222

208.67.220.220

Regards Simon
http://www.linksysinfo.org

[Te-Kai Liu · Accepted solution]

Static DNS Servers can be specified at the DHCP>Setup page. The DNS Servers thus configured will take precedence over the DNS Servers provided by your ISP when the WAN links go live.

[Davidwagman1 · Accepted solution]

Hi Sharon,

It sounds like the DNS servers from Wan 1 (distributed via dhcp to your hosts) are not accessbile when connected to wan 2, a different ISP? Is that correct? Wan 1's DNS is ISP's DNS and is not accessible by wan 2?

You can test failover by using google public DNS (8.8.4.4), which should be accessible by both networks rather than ISPs dns.

Can you ping the wan 1 DNS servers from wan 2?

Best,

David

Please rate helpful posts.

[Sharon Grady]

First off, thank you everyone for your replies.

David,

   Yes, I can ping the DNS servers from WAN1 when I am connected to WAN2, but the ping fails about 1/2 of the time.

Tekliu and Simon,

   I will try to change the settings to what the 2 of you recommend and will post results later.

Thanks again everyone.

[Sharon Grady]

Tekliu and Simon,

   I combined your two answers by using the OpenDNS servers in the DHCP Setup screen and then ipconfig /refresh ipconfig /renew on the computers.  I then unplugged WAN1.  And I was still able to resolve DNS. 

Thanks!!!!!

[linksysinfo]

Sharon Grady wrote:
Tekliu and Simon,
   I combined your two answers by using the OpenDNS servers in the DHCP Setup screen and then ipconfig /refresh ipconfig /renew on the computers.  I then unplugged WAN1.  And I was still able to resolve DNS.  
Thanks!!!!!

No problem, glad it helped you out

Regards Simon
http://www.linksysinfo.org