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> Chapter 14 - IPsec VPN > GRE over IPsec (Cisco VPN) > Configuring the Cisco router

Configuring the Cisco router

Using Cisco IOS, you would configure the Cisco router as follows, using the addresses from the example:

config ter

crypto ipsec transform-set myset esp-3des esp-md5-hmac

no mode


no ip access-list extended tunnel

ip access-list extended tunnel

permit gre host host


interface Tunnel1

ip address

tunnel source

tunnel destination


ip route Tunnel1


clea crypto sa

clea crypto isakmp

For transport mode, change no mode to mode transport.

This is only the portion of the Cisco router configuration that applies to the GRE-over-IPsec tunnel. For more information, refer to the Cisco documentation.