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Site to Site vpn with dyndns at one end


If u can help me that would be great.

I have two site with SA540

Site A:- i have a public Ip x.x.x.x with Lan ip

Site B :- i have Broadband router with dyndns to which SA540 is connecte with WAN Ip

The lan ip ports to fwd on broadband router to SA540.


Site to Site vpn with dyndns at one end

What exactly are you wanting to know?  I'm not sure I see a question here.

New Member

Site to Site vpn with dyndns at one end

Dear Cflory,

As i want to have a site to site ipsec tunnel between Site A and Site B

On Site A :-

I have SA540 with public ip x.x.x.x Lan Ip

On Site B :-

I have Linksys router to which my ADSL Line is connected its lan ip is

for vpn tunnel i have taken cisco SA540 on my wan interface the ip is and the lan ip is

As in my Site B i dont have an public ip so i am using Dyndns ( is configured on my linksys router so i would like to know what configuration i should make on my Site A.

I think this picture will give you some information...

If u can help me by giving the configuration as i have never with DYNDNS..

New Member

Site to Site vpn with dyndns at one end

Plz any one can help with the configuration

New Member

Site to Site vpn with dyndns at one end

This is my Site B configuration.....

access-list NO-NAT permit ip

access-list 101 permit ip

pager lines 24

logging on

mtu outside 1500

mtu inside 1500

mtu intf2 1500

!--- Wan Ip address from Linksys router where Dyndns is confirured

ip address outside

ip address inside

global (outside) 1 interface

nat (inside) 0 access-list NO-NAT

nat (inside) 1 0 0

route outside 1

!--- IPsec configuration, Phase 2.

crypto ipsec transform-set esp-des esp-md5-hmac

crypto map IPSEC 10 ipsec-isakmp

crypto map IPSEC 10 match address 101

crypto map IPSEC 10 set peer x.x.x.x

crypto map IPSEC 10 set transform-set

crypto map IPSEC interface outside

!--- policy, Phase 1.

isakmp enable outside

isakmp key cisco123 address x.x.x.x netmask

isakmp policy 10 authentication pre-share

isakmp policy 10 encryption des

isakmp policy 10 hash md5

isakmp policy 10 group 1

isakmp policy 10 lifetime 86400

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