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New Member

DHCP relay through IPSec VPN IOS routers

How can I implement and is it possible DHCP relay between two routers with IPSec VPN.

From one site clients need IP address from DHCP server on the other site.


Re: DHCP relay through IPSec VPN IOS routers

ip helper-address command to allow DHCP traffic over VPN. I found a configuration example to implement this command:

Try to apply this command on the same interface where crypto mpa is applied:

Router(config)#interface s0

Router(config-if)#crypto map mymap

Router(config-if)#ip helper-address

DHCP is sending a broadcast traffic and broadcast traffic is not supported over VPN. However, you may try to configure GRE over IPSec on your routers to implement this goal.

You may visit these links regarding GRE over IPSec:

New Member

Re: DHCP relay through IPSec VPN IOS routers

Is it possible to do it without GRE because I have only one Public IP address per site. What I know GRE requests additional IP addresses, am I right?