Scenarios Depicting IPsec Nat-traversal
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Alcatel-Lucent
Beta Beta
OmniAccess 5740 Unified Services Gateway CLI Configuration Guide
SCENARIOS DEPICTING IPSEC NAT-TRAVERSAL 
Figure 32: IPsec Scenario with NAT-Traversal
When both the IPsec peers Host 1 and Host 2 are behind NAT. Both peers being 
NAT-T capable detect NAT during the main mode negotiation and peers switch to 
port 4500.
OA5740-A
ALU(config)# show match-list
match-list m1
1 ip prefix 192.168.0.0/24 prefix 172.16.2.0/24
!
ALU(config)# interface GigabitEthernet 3/0 
ALU(config-if GigabitEthernet3/0)#ip address 202.50.24.2/24 
ALU(config-if GigabitEthernet3/0)#crypto-map map1
 
ALU(config-if GigabitEthernet3/0)#show crypto
crypto ike key secret peer 202.50.24.1
!crypto ike policy default
!       proposal md5-des
!       ipsec security-association lifetime seconds 28800
!       lifetime seconds 86400
!       pfs group2
!crypto ipsec transform-set default
!       esp-md5-des esp-sha1-des
crypto map map1 ipsec-ike default
        peer 202.50.24.1
        match m1
        transform-set default
        pfs group2
! Applied to : GigabitEthernet3/0
interface GigabitEthernet3/0
        crypto map map1
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