Adding lan pool to cisco router

Question

dear all ,
i work as a network engineer in a company and need a help.
i work in head office and we also have a branch office , we are configuring  a DR site so first we kept all the servers in HO for testing but our clients need to assign a branch office lan ip and the same gateway on a DR server  in head office ,later we l move to DR
HO
ip:192.168.100.XXX
subnet: 255.255.255.0
gateway:1192.168.100.1
branch
ip:192.168.102.XXX
subnet:255.255.255.0
gateway:192.168.102.1
so, i tried to asign a IP     192.168.102.250                         
                                   subnet: 255.255.255.000
                                     gateway:192.168.102.1
this is what the clients need but after a assign i am not able to ping any HO lan ip from this machine but i am able to ping this machine from other machines in HO
i think we need to add branch office lan pool in HO router is it rite or what should i do..
here is my HO router configuration
interface FastEthernet4.1004
interface FastEthernet4.1175
encapsulation dot1Q 1175
ip address 94.77.XXX.XXX  255.255.255.252
ip nat outside
ip virtual-reassembly in
interface wlan-ap0
description Service module interface to manage the embedded AP
no ip address
arp timeout 0
!f
interface Wlan-GigabitEthernet0
description Internal switch interface connecting to the embedded AP
no ip address
interface Vlan1
ip address 192.168.100.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
ip forward-protocol nd
no ip http server
no ip http secure-server
ip nat inside source list 10 interface FastEthernet4.1175 overload
ip route 0.0.0.0 0.0.0.0 94.77.XXX.XXX
access-list 10 permit 192.168.100.0 0.0.0.255
control-plane
line con 0
line aux 0
line 2
no activation-character
no exec
transport preferred none
transport input all
line vty 0 4
login local
transport input all
end

Answer 1

Hi,
Sounds like ip routing problem here. How are HO and branch offices connected? Network topology would be helpful.
Hope it will help.
Best regards,
Abzal