Posted: Tue Mar 09, 2021 9:19 Post subject: DDNS does not work
Hello forum
I have just installed the DD-WRT firmware Firmware: DD-WRT v3.0-r45849 std (02/25/21) to a Netgear X8 R8500 (A). I am currently connected to the internet via VDSL using a Zyxel modem/router (B) which is connected to A-R though a static route (see post https://forum.dd-wrt.com/phpBB2/viewtopic.php?p=1231239#1231239)
In my previous setup I used just B-MR and DDNS worked fine. Now I disable DDNS on B-MR and enabled it on A-R and it does not work. Should I disable DHCP on B-MR? Should I create a new NAT rule on A-R? Should I set to yes 'Úse external IP Check'?
Status looks OK
Tue Mar 9 11:35:44 2021: INADYN: Started 'INADYN Advanced version 1.96-ADV' - dynamic DNS updater.
Tue Mar 9 11:35:44 2021: INADYN: IP read from cache file is 'n.m.i.j'. No update required.
but I cannot ping.
If I disable dynamic DNS on router A and enable on modem-router B I can ping but still I cannot access myserver from outside
VPN is active but this should not care right?
Please help
Thanks much
Last edited by stanzani on Wed Mar 10, 2021 10:34; edited 1 time in total
Joined: 18 Mar 2014 Posts: 12837 Location: Netherlands
Posted: Wed Mar 10, 2021 10:52 Post subject:
I already tried to explain it to you but I will try once more.
DDNS takes your WAN IP address and places that in the DNS record.
Your router B is a secondary router which does not have a public IP address so the WAN IP address is not working here.
DDWRT's DDNS implementation has a trick to overcome this if you enable/YES for "External IP check" then it will use a similar query like you are doing with browsing to ipleak.net (and the likes) so it will find your public IP address.
So from a secondary router you should enable this.
However if you are using a VPN client on this secondary router then the external IP address is the IP address of your VPN provider.
Thanks for your reply and please forgive my donkeyness
I tried your suggestion but I cannot ping my ddns host also in the last case (DDNS enabled on modem router and disabled on secondary router). All ports looks closed if I check with https://www.portcheckers.com/ and I cannot ping by dynamic IP hostname
I am now working in the NAT/QoS tab of B and I wonder how should I set the 'Source address' field. I guess I should set to the IP of B (address are inside the LAN of B) but does not work
Last edited by stanzani on Wed Mar 10, 2021 12:01; edited 1 time in total
Joined: 18 Mar 2014 Posts: 12837 Location: Netherlands
Posted: Wed Mar 10, 2021 11:42 Post subject:
IF you want to reach anything on the LAN of secondary router B you have to set a port forward on router A and a port Forward on Router B for that client on LAN B.
(and yes you can also set a static route on router A and open the firewall of router B but that is for the advanced class)
When you are using a VPN client on router B it will not work at all because traffic goes in in the WAN interface and by default routes out via the VPN and that will be blocked.
In that case you have to use Policy Based Routing for the VPN client.
First disable the VPN client and then get Port forward working after it works you can enable the client and start working on PBR
I am sorry but for some black magic this is not working any longer. There is a possibility I badly checked this and I was too happy before
I set PBR rule in the VPN as 192.168.1.xxx/yyy
I enabled ddns on A (the modem/router) and disabled on router B.
Still I cannot ping myhost.ddns.net if VPN is enabled
DHCP is enabled on both A and B
... ddns works if I disable VPN on router B ....
My setup is still ... temperamental
I have a PC in my home network running a media server , address is IPADR: 192.168.1.MMM The port NN is forwarded on both router A and router B at IPADR
All of this works with VPN off i.e. I can access to the server by <mydns>.ddns.net:NN
What else should I forward?
IPADR is in the PBR list of the VPN text box