i have already configured site to multi Site VPN in my packet tracer and always only 1 site can connect successfully and the other site cannot continue here is the result from isakmp sa
IPv4 Crypto ISAKMP SA
dst src state conn-id slot status
212.76.68.1 172.21.6.1 MM_SA_SETUP 0 0 ACTIVE
109.63.62.1 172.21.6.1 QM_IDLE 1050 0 ACTIVE
>>>>> configuration of may Main Offic Router
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version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
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hostname Router
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!
!
!
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!
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crypto isakmp policy 1
encr aes
authentication pre-share
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crypto isakmp key cisco address 79.95.25.1
crypto isakmp key cisco address 109.63.62.1
crypto isakmp key cisco address 212.76.68.1
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!
crypto ipsec transform-set VPN_Trans esp-aes esp-sha-hmac
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crypto map VPN_Map 1 ipsec-isakmp
set peer 79.95.25.1
set peer 212.76.68.1
set peer 109.63.62.1
set transform-set VPN_Trans
match address NAT_Group
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!
!
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spanning-tree mode pvst
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interface FastEthernet0/0
ip address 172.20.21.1 255.255.255.0
ip nat inside
duplex auto
speed auto
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interface FastEthernet0/1
ip address 172.21.6.1 255.255.255.252
ip nat outside
duplex auto
speed auto
crypto map VPN_Map
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interface Vlan1
no ip address
shutdown
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router rip
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ip nat inside source list NAT1 interface FastEthernet0/1 overload
ip classless
ip route 0.0.0.0 0.0.0.0 FastEthernet0/1
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!
ip access-list extended NAT_Group
permit ip 172.20.21.0 0.0.0.255 192.168.0.0 0.0.0.255
permit ip 172.20.21.0 0.0.0.255 10.72.139.0 0.0.0.255
permit ip 172.20.21.0 0.0.0.255 192.168.1.0 0.0.0.255
ip access-list extended NAT1
deny ip 172.20.21.0 0.0.0.255 192.168.0.0 0.0.0.255
deny ip 172.20.21.0 0.0.0.255 10.72.139.0 0.0.0.255
deny ip 172.20.21.0 0.0.0.255 192.168.1.0 0.0.0.255
permit ip any any
ip access-list extended NAT
permit ip 172.20.21.0 0.0.0.255 10.72.139.0 0.0.0.255
ip access-list extended NAT2
permit ip 172.20.21.0 0.0.0.255 192.168.0.0 0.0.0.255
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no cdp run
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line con 0
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line aux 0
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line vty 0 4
login
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!
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