OpenDNS Server Not Resolving Hostnames to Correct IP addresses

pgrossman · ‎01-08-2019

I have 2 voip routers where OpenDNS server 208.67.222.222 is not resolving the SIP provider's outbound proxy server hostname with either of the 2 correct IP addresses. This is causing all IP phones to try and register with the incorrect outbound proxy IP. I have implemented a work around to bypass dns lookups for now.

The issue is that OpenDNS server 208.67.222.222 is resolving g1-ne01.nms.outboundproxy.com to 146.112.61.106. 146.112.61.106 resolves to hit-adult.opendns.com which is of course not a valid SIP server for the phones to register to. I have the issue using both Verizon Enterprise and Lightpath internet circuits on one router and then just FIOS on another.

Below nslookup shows the issue. Same lookup on other routers does not have the issue. https://cachecheck.opendns.com/ shows the correct IP for this hostname which 70.42.44.15. I do not subscribe to any OpenDNS service and just use 208.67.222.222 as my router secondary DNS server, for the WAN, and all LAN devices. Are my affected router's WAN IP on some sort of black list with OpenDNS?

# nslookup g1-ne01.nms.outboundproxy.com 208.67.222.222
Server: resolver1.opendns.com
Address: 208.67.222.222

Name: g1-ne01.nms.outboundproxy.com
Address: 146.112.61.106

# nslookup 146.112.61.106
Server: google-public-dns-a.google.com
Address: 8.8.8.8

Name: hit-adult.opendns.com
Address: 146.112.61.106

rotblitz · ‎01-09-2019

Strange, domain g1-ne01.nms.outboundproxy.com is not categorized at all.

Whatever, it looks like you inherited a dynamic IP address which is still registered with another user account's dashboard, so you are using this user's settings.

You raise a support ticket, link "Submit a request" above, to report this case. They may correct the categorization stuff and may release your IP address from registration.

pgrossman · ‎01-09-2019

Very strange. I have not even configured anything in my dashboard as the only reason I registered was to try and open a ticket. It only happened on 2 of maybe 200 routers that use OpenDNS DNS servers. I figured I would post here first.

Anyways the issue is no longer occurring today. I cannot continue to use OpenDNS server though.

Thank you.

rotblitz · ‎01-09-2019

So, did you raise a support ticket because of the suspected glitch? You really should!
I cannot, because I do not face this issue and cannot reproduce it.

The domain g1-ne01.nms.outboundproxy.com should never resolve to hit-adult.opendns.com, because it is not categorized at all and therefore would not be able to produce this result.
https://domain.opendns.com/g1-ne01.nms.outboundproxy.com

Also, unless your VoIP provider explicitly requires to use a proxy server, you don't need to configure one. You just configure the SIP registration server. Bad enough if this and the proxy server have the same domain name and still resolve to hit-adult.opendns.com.

pgrossman · ‎01-09-2019

I might raise a ticket. VoIP provider has SIP server redundancy via DNS SRV. In order to take advantage we need to register using the outbound proxy server hostname instead of IP address direct so the phones can attempt to register with the primary or secondary IPs for the SIP servers. Registration server and proxy server are kind of the same thing in this case.