Posted: Sun Aug 30, 2015 2:15 Post subject: DNSMasq + OPtion66
I have a network that has two routers. One is on a T1 with DDWRT V24, DHCP turned off, in the DNSMAQ options we have DHCP-Option 66 entered. This router is connected to our Data T1 for VoIP calls. The other router is a Tomato router. It is setp on our Cable company an is the DHCP server for our network and is the primary gateway for the network. Here is my question: Since the DDWRT router doesn't serve as the DHCP server, how would an IP phone get the tftp server address for the IP phone config files? Does the DNSMASQ do this in response to the DHCP requests?
Joined: 10 Jan 2015 Posts: 270 Location: Minnesota
Posted: Sun Aug 30, 2015 10:10 Post subject:
Are your VoIP phones working? Because i would believe that turning off DHCP would disable DNSmasq or udhcpd (they are each possible daemons for controlling DHCP) from working, making the option 66 variable irrelevent.
My take (even though i've never dealt with automating or setting up a VoIP system) is that the DHCP server would need to be active as DNSmasq is part of that service.
The scenario is : We have a noob who is learning all the words but no theory. He says he took a phone and was able to provision it using Option 66 as I described previous. I suspect all he did was clear the account info in the phone and reboot it. The TFTP server entry would have been intact. This all came about as we are selling VoIP systems and we want to include a Router. Our goal is to have a turnkey system where the end user has an existing network with multiple WAN IPs, we can come in use an available WAN IP with our router on their network, DHCP turned off. Set our router to be the gateway for the phone server and have all our port forwarding and such in place. Provisioning the phones with the TFTP server on the phone server is or can be a big deal. So tomorrow I will go in and "Recreate" his test and see what happens. I am pretty sure it won't work.
It is the DHCP server that informs the clients that there is a TFTP server on the network. In your first scenario, the Tomato router would do that. _________________ 2 times APU2 Opnsense 21.1 with Sensei
2 times RT-AC56U running DD-WRT 45493 (one as Gateway, the other as AP, both bridged with LAN cable)
3 times Asus RT-N16 shelved
E4200 V1 running freshtomato 2020.8 (bridged with LAN cable)
3 times Linksys WRT610N V2 converted to E3000 and 1 original E3000 running freshtomato 2020.8 (bridged with LAN cable)
Joined: 10 Jan 2015 Posts: 270 Location: Minnesota
Posted: Mon Aug 31, 2015 9:12 Post subject:
slobodan wrote:
It is the DHCP server that informs the clients that there is a TFTP server on the network. In your first scenario, the Tomato router would do that.
And this is where i questioned the setup. If you have variables entered into the router that has its DHCP disabled, how would the IP phone(s) know where to receive the provisioning file from if the Tomato router is the DHCP server without option 66 configured?
Again i at least think option 66 would only work if the DHCP server it resided on was active.
Else any IP phone wont know to auto-provision itself with using that TFTP server unless option 66 was set up on the tomato router. _________________ LATEST DD-WRT FW IS LOCATED HERE: https://dd-wrt.com/support/other-downloads/?path=betas%2F
