Multiple cobbler servers with single dhcp server in the same subnet

*I have two Cobbler Servers and one dhcp server, let us say 10.x.x.51 and 10.x.x.52(cobbler servers), 10.x.x.53(dhcp server).I have created profiles from iso which is mounted in each cobbler servers.I have created two pxe enabled bare metals and configured with the mac addresses in /etc/dhcp/dhcpd.conf of 10.x.x.53

Now, when i try to power on the pxe enabled bare metals, then i am able to get the ip from dhcp and load kernal packages but while booting up i am facing issue (checking mirror and stopping there).It is working if the dhcp server is local to the individual cobbler setup.*

Grouping is the concept which is available in dhcp, so if we configure this we can maintain common dhcp with multiple cobbler servers.

dhcpd.conf:

allow booting;
allow bootp;

    ignore client-updates;
    set vendorclass = option vendor-class-identifier;

    subnet 10.x.x.0 netmask 255.255.255.0 {
          option routers 10.x.x.1;
          option domain-name "test.co.in";
          option domain-name-servers      10.x.x.100;
          option subnet-mask      255.255.255.0;
          range   10.x.x.122 10.x.x.132;
          default-lease-time 21600;
           max-lease-time  43200;
     }

    group {
               filename "/pxelinux.0";
               next-server 10.x.x.51;

               host vmone { hardware ethernet <mac_address_baremetal_1>; }
           }

    group {
               filename "/pxelinux.0";
               next-server 10.x.x.52;

               host vmtow { hardware ethernet <mac_address_baremetal_2>; }

          }