GRE tunnel configuration issue on Firewall.

[raut.pawan]

Hi I am trying to configure GRE tunnel between source and destination. Firewall come in between this. What is the rule need to be configured on Firewall.

Which ports need to be open for source to destnation and destination to source on Firewall

[syed kazim abbas]

Hi, 

you need an ACL for outside to permit gre protocol and static nat if u using nat

for further see this link

http://www.cisco.com/c/en/us/support/docs/security-vpn/ipsec-negotiation-ike-protocols/14381-gre-ipsec-ospf.html

http://www.networkstraining.com/configuring-gre-tunnel-through-a-cisco-asa-firewall/

Regards,

kazim

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