Can i connect two routers with EIGRP if a firewall is between them

[rene.gonzalez1]

Hi everybody, this is my first post ever. I have been asked to configure a network topology where an internal new router can establish an eigrp adjacency with the companys border router that is located after the firewall. Is this possible? do i have to configure EIGRP in the firewall or can i create a rule in the firewall that lets the EIGRP traffic go trhough the firewall between my two routers.

Hope someone can help me out.

the topology woulb be like    <R1>-----<FW>-----<R2>

[Deepak Kumar · Accepted solution]

Hi, 

In your case without configuring the eigrp on the firewall, router to router neighborship is not possible in the EIGRP protocol but you have a solution that you can make a tunnel interface between your both router and configure the EIGRP on that tunnel interface. Then It will work without involving the firewall in the EIGRP configuration. 

Regards,

Deepak Kumar

[rene.gonzalez1]

Thanks I appreciate it. Do i have to permit any port in the firewall? o make any configuration in the firewall?

Best regards.

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[Deepak Kumar]

Hi, 

What services and which mode is configured on the firewall? Is it in Transparent mode or routed mode?

If it is in routed mode (NATING) configured on the firewall then you should make a destination nat between both routers to allowing GRE (IP Protocol number 47) must be allowed. 

Regards,

Deepak Kumar

[rene.gonzalez1]

Hi, it is a fully functional corporate Firewall. I just wanted to know if i have to ask to the security department for any special configuration or open port on the FW to stablish the EIGRP adjacency between my border and my inside router.

Thanks,