VPN terminated on Loopback IP

Unanswered Question
Oct 6th, 2008
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Hi all,

I'm willing to configure a VPN client on my 2691 router [run IOS ver. 12.4(15)T7]. the network setup is quite simple, as following

ADSL router --> VPN router

I've configured a loopback 0 to terminate the VPN sessions but to no avail, for curiosity reason I've tried to terminate the VPN on the Fa0/0 and amazingly working fine.

crypto isakmp policy 1

encr 3des

authentication pre-share

group 2

crypto isakmp client configuration address-pool local dynpool


crypto isakmp client configuration group hasan-gr

key hasan-key



pool dynpool



crypto ipsec transform-set transform-1 esp-3des esp-sha-hmac


crypto dynamic-map dynmap 1

set transform-set transform-1




crypto map dynmap isakmp authorization list hasan-gr

crypto map dynmap client configuration address respond

crypto map dynmap 1 ipsec-isakmp dynamic dynmap







interface Loopback0

ip address

ip nat inside

ip virtual-reassembly

crypto map dynmap


interface FastEthernet0/0

ip address

ip nat outside

ip virtual-reassembly

speed 100


ip nat source static

ip local pool dynpool

ip forward-protocol nd

ip route

any helpful comments will be higly appreciated..


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Overall Rating: 3 (1 ratings)
cisco24x7 Mon, 10/06/2008 - 05:48
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Your loopback 0 needs to be visible for this

to work.

Richard Burts Mon, 10/06/2008 - 07:38
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For the VPN tunnel to work when terminated on the loopback it would also be necessary to configure the crypto map local-address command. By default the crypto will use the address of the outbound interface. So when terminating the VPN on the physical interface local-address is not needed. To use the loopback you need the configuration command to change the address used from the physical outbound interface to the loopback.




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