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  1.  permalink

    If I setup the main router to use Open DNS the VOIP feature built in to my main router stops working. I can dial any number and people pick up the phone when I dial but I can't hear them and they can't hear me.

    1 express
    1 airport extreme

    The express is connected to the main router via ethernet.
    The express is setup to create a wireless network and is in bridged mode to avoid double NAT issues
    The extreme is extending the express's wireless network.

    My main router has a VOIP feature and work without issue.

    Originally I set up my Airport network to point it's DNS to OpenDNS instead of the main router but it did not work, no sites were blocked.

    I then removed the OpenDNS entries from my Airport Network and entered OpenDNS IP address on my main router but when I did this the VOIP feature broke. I experienced the issue I mentioned above. However; OpenDNS would work perfectly, as expected.

    Can someone recommend something for me please?

    Unfortunately, I live in Poland and I doubt my ISP can or will help. Not speaking Polish makes matters worse to get their support.

    Thanks so much and if at all possible try to reply in simple terms, I know somethings but not being able to figure this out myself puts into doubt some of my self-learned knowledge.

    Many thanks in advance.
  2.  permalink
    Your ISP can't help with LAN issues anyway. This is more a router support issue.

    Yes, configuring DNS addresses on an ISP-provided gateway (I'm surprised the option is even available) will break VOIP and IPTV, which depend on ISP WAN domains that don't exist outside the ISP's network.

    You should be able to configure the Express without issue. Had you flushed browser and local resolver caches after configuration?

    As far as I know, Apple devices do not have WAN/internet DNS forwarders, but give DNS addresses to client devices via DHCP.

    I've had some vague indication that maybe some do have static DNS settings available on the WAN side - can you say where you configured the addresses? This makes a difference. For now, I'm assuming that the settings are on the LAN side, to which the following information applies.

    If the addresses are configured in LAN/DHCP settings, then all devices must have the LAN IP address of the Express as their DHCP server. All devices must connect to the gateway via the Express. The Extreme must connect only through the Express, the Express cannot be the DHCP server for DNS unless you also configure the OpenDNS addresses there. The gateway cannot be the DHCP server, or your other router settings are ignored (well, they simply do not exist at all for client devices).

    You may or may not be able to fulfill these requirements with the routers bridged.
    Thankful People: zelus
  3.  permalink
    I will answer as I best I can on a per paragraph basis - you wrote 7 paragraphs.

    Paragraphs 1 and 2
    Yes it is a LAN issue I agree. I was originally pointing the ISPs router to OpenDNS and it worked fine but the phone couldn't receive incoming or outgoing calls, there was a dial tone and the touch tone would work and the call would reach the recipient but we couldn't hear each other. I confirmed this. I rarely watch TV so I do not have any confirmation on this but we can suppose you are right.

    Paragraph 3
    The Airport Express which connects to the ISPs router via ethernet is currently setup from the Internet tab as follows:
    Connect using: DHCP
    IPv4 address:
    Subnet Mask:
    Router Address:
    DNS Servers: and
    IPv6 DNS Servers: Blank
    Domain Name: home (greyed out) - I think this is a default name due to the test "home" appearing greyed out.

    In terms of the "DNS Servers" entry which as you can see above is OpenDNS is a bit of a problem because the ISPs router (WAN) is provided a dynamic IP address and the "OpenDNS Updater" application can only go as far as my ISPs router to query the current Public IP address. So currently, although my Airport Express (LAN) is set to OpenDNS my network (LAN) can't take advantage of what is in my OpenDNS Dashboard, porn blocking, phishing blocks etc.

    Paragraph 4
    I am not sure exactly what you mean. I suspect you are trying to understand how an Airport router provides its clients the DNS address.

    Paragraph 5
    You would like to know where I configured the address - I suspect OpenDNS addresses.
    1) At first, I added the OpenDNS addresses directly on my ISPs Router (my WAN or gateway, whatever you want to call it)
    2) This worked beautifully in conjunction with OpenDNS updater but as I've mentioned my phone wouldn't work and probably IPTV, but as I mentioned above I didn't test it out of a habit of not watching TV.
    3) After I realised I have no phone, which is kind of mission critical, I removed OpenDNS entries from the ISPs router and set them back to 'default' and proceeded to add them to my Airport network but that wouldn't allow OpenDNS to take advantage of what the settings in my OpenDNS dashboard. This is likely due to the fact that OpenDNS Updater can't find out my dynamic public IP address any more as the source (the ISPs router) isn't associated to that DNS any longer.
    4) So here I am…
  4.  permalink
    part 2

    -- You asked me where I configured those addresses, again, I assume you mean the OpenDNS addresses. I added them to my ISPs router config page. I can tell you where.
    1) From the main configuration page for the ISPs router there are a number of options running down the left side, I've listed them below and they are classified under "Configuration"
    PPP Settings

    - I clicked DNS and I get the following below:

    <two options below for "Set the hostname", they are radio buttons, so automatic or manual is possible>

    Set the hostname
    Automatically via DHCP

    <If I choose manually, I can then enter a Primary and Secondary DNS, which is how I did set it up but the phone wouldn't work>

    Primary DNS :
    Secondary DNS :

    -- What do you suppose is meant by "hostname"? Is it significant? I hope this is what you wanted to know. Yes, at the moment settings are on the LAN side. Prior to creating this discussion thread it was on the WAN side (The ISPs Router)

    Paragraph 6
    You said: "If the addresses are configured in LAN/DHCP settings, then all devices must have the LAN IP address of the Express as their DHCP server."
    -This is true.

    You said: "The Extreme must connect only through the Express, the Express cannot be the DHCP server for DNS unless you also configure the OpenDNS addresses there."
    -Yes, the Extreme is setup to "Extend a wireless network" and that wireless network is the Express's wireless network. So the Extreme can't do anything unless the Express is fully operational, the Extreme in this configuration assumes all settings from the Express. Think of the Extreme as serving the purpose of making the Express's wireless network larger. Does this make sense?

    You said: "The gateway cannot be the DHCP server, or your other router settings are ignored"

    -So you are suggesting that I turn of routing on my gateway (ISPs router) — dumb it down to a modem. I am not sure how this would make a difference, in fact I wonder if it will impact my phone (VOIP) and IPTV. Is this what you mean and would you like me to try this. This would mean turning off DHCP on the gateway, correct?

    Paragraph 7 ignore for now

    ------ My thoughts
    I think the problem here is two fold, let me know your thoughts please and yes, I sincerely appreciate your ideas and help.
    1) OpenDNS Updater, an app for the mac, contacts OpenDNS to deliver it my public IPv4 address. With this knowledge, OpenDNS dashboard settings can be applied and my network behaves as per the settings in OpenDNS dashboard. This is how I think it works.

    2) If I set the gateway to use OpenDNS everything works as advertised but in my case, VOIP and IPTV (latter not confirmed) fail to operate as expected — an issue that does not concern OpenVP and rightly so, it's not their service causing the issue.

    3) If I set OpenDNS on my Apple Airport Network, it doesn't work with what is set in OpenDNS Updater because of my dynamic public IP address.

    That's all I can say for now. I sincerely appreciate the time you have taken to read this and any feedback would be very much appreciated.

  5.  permalink
    I fixed it. I am sharing this with you and the community. Again, please note that the ISPs router has IPTV and VOIP built-in

    I started thinking about your suggestion to what I assume was turning off DHCP on the ISPs router. So here is what I did;

    1) Deactivated DHCP on the main router - ISPs router, it's now basically dumbed down to a modem only.
    2) Allocated a private fixed IP address to my Airport Express on the local network - I used both the MAC address and IP address (

    3) Reset both the Express and Extreme to factory default settings and setup the Express only while testing.
    3) The Airport Express is setup to use a static IP address, The Router address is still and the DNS Servers are and
    4) To avoid double NAT I set the Airport Express's router mode to DHCP only.
    5) Added the Airport Extreme to extend the Express's WIFI network.
    6) I flushed DNS cache on my mac using the following command…

    sudo killall -HUP mDNSResponder (this could have worked too --> sudo killall -INFO mDNSResponder) but kind of heavy.

    this resulted in the following log as seen in the system.log

    alexs-imac.home mDNSResponder[42]: SIGHUP: Purge cache

    and…life is good! Wonderful stuff.

    I hope this helps others who use an ISP supplied router that delivers VOIP and IPTV - maybe you can't set the OpenDNS directly on those routers. You may have to point a second router to OpenDNS as I've done here.

    PS This is not why I bought an express and extreme, it was actually to create a new WIFI Network and extend it with the extreme.

    Thanks again!

    Thankful People: zelus
  6.  permalink
    One more point of interest.

    I noticed now that my Network System Preferences auto populates OpenDNS IP addresses automatically in the DNS tab and they are not removable.

    This setup is now golden!

    I can connect from any of the WIFI networks and the stuff in my dashboard work so does OpenDNS Updater.

    Kind Regards
  7.  permalink
    This looks good. Your Airport DNS config is, from the evidence, LAN/DHCP only, and now that devices have this as their DHCP server, they get OpenDNS addresses.

    I glad everything is now working for you. Enjoy!
  8.  permalink
    One more interesting tidbit

    I ran telnet on the ISP router and started poking around (after resolving things) - it's a nice way to learn and I found a command called Utilization in the QOS section…turns out that is the static IP my Express lives on :)

    Of course this is for QOS but tit reveals the truth. Tech is fun!

    qos> utilization
    host application throughput(Kbps)
    tx rx
    -------------------------------------------------------- Secured Web Server 1.1 4.2 Domain Name Server, UDP Domain Name Server 0.5 1.0

This discussion has been inactive for longer than 30 days, and is thus closed.