However, I have some challenges at hand and need your expert help.
We have two sites, Main and remote. Both sites use Mikrotik router and are interconnected via IPsec VPN over a public internet. Site to Site configuration is already done and working very fine. All subnets are fine as well. The challenge we have is with our Cisco Voice gateway( Cisco ISR 2911). The Cisco voice gateway is configured and working ok from the Main site. IP Phones register easily and can call each other. We moved some configured phones to the remote site and they cant register to the Voice gateway. Is there anything that is blocking the registration or dhcp ip? How can we configure the remote/main router to allow the IP Phones pick IP Addresses and register to the voice gateway located at the Main site? We have been on this for some days now, exhausting all the posts on the internet.
Mrz, thanks for quick reply but this scenario does not address my request.
Am talking about two sites that connect over the public internet using ipsec vpn. The DHCP is on a Cisco 2911 router connected to LAN(VLAN 12). What we want is for Cisco IP Phones connected on Remote LAN to be able to pick ip address and register on the Cisco 2911 located on the main site.
Since you’re using IPSec in this manner, this means the connection is a routed connection, and not a bridged connection. Basic DHCP depends on being in the same broadcast domain as the server, which just isn’t doable with your current configuration. DHCP relay fixes this, but the server will need to have the remote site’s network added as an additional DHCP scope.
Another solution is to simply run a DHCP server at the remote site which gives the necessary DHCP option that the phones use to learn what the call agent IP is.
I can’t tell you exactly what to do, because I don’t know what DHCP options your phones require, etc.
However, if you know the correct ones and the correct values for your networks, then adding them to a Mikrotik DHCP server is pretty easy.
In the DHCP server menu, there’s a tab where you can define custom DHCP options.
Create them there, and then in the Networks list, add your custom options to the scope, and that should do the trick.
thanks again but unfortunately this is not working.
i configured the DHCP server on mikrotik as you recommended with the option 150. the Ip Phone could not pick up IP address. from the dhcp log, i saw "received discover from xx:xx:xx:xx:xx:xx from unknown giaddr x.x.x.x. Please help more.
