DHCP failover doesn't receive DHCP requests in secondary server

[Roberto Carna]

Dear people,

I´ve implemented a failover scheme with ISC-DHCP-SERVER in two
different servers, with the same version of the package and OS.

Everything seems to be OK, but when a execute "service isc-dhcp-server
stop" in the primary server, in the secondary server I can see:

Aug 15 11:52:01 dhcp2 dhcpd[5839]: peer dhcp-failover: disconnected
Aug 15 11:52:01 dhcp2 dhcpd[5839]: failover peer dhcp-failover: I move
from normal to communications-interrupted

what is correct, but after that the secondary server doesnt' receive
any DHCPREQUEST packet from clients.

So, my faoilover scheme doesn't work, because if primary server goes
down, the secondary server doesn't receive any IP request from
clients. When I start the isc-dhcp-server on primary server, at this
moment I can see the DHCPREQUEST from clients to primary server.

What can be the problem with the secondary server please ???

Thanks a lot!!!