[SR-Users] Question about LCR ping option

Hello I am using kamailio 1.5.2. Our kamailio server has multiple IPs, and 1 of them happens to be a private IP for management purposes. When enabling the "ping" feature of the LCR module the machine sends the OPTIONS messages from the private IP. I need it to use at least any of the public IPs and if I can specify it it would be even better. I tried using the directive "ping from" with one of the public IPs but it only uses it to populate the "From" header, not to send the message from. One option could be to configure the configuration file with the "listen" directive including only the public IPs. However, there are more than 50 IPs, is there a limit to the number of IPs? I tried with a subnet and it is not allowed. Is there any other work around? txs a lot fborot