Hierarchy of routing statements in ISR

[Miguel Alejandro Callejas Pastor]

Hi, 

I was looking information about the order in which the router processes packets. If the router had statements to forward packets from a specific IP address, what statement will be processed first? 

Let's suppose the router has the following statements (all matches with a single IP address):

- A route map to redirect traffic to another interface.

- A nat (pat) statement to translate ip addresses to a single public ip address.

- An access list to deny it.

- A static route to forward traffic to another router (different from the route map).

- An IPSec VPN that have a "nat traversal" statement different from the PAT statement. 

I hope you could help me with the order of hierarchy. What will the router do first?

Thank you a lot. 

Miguel

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

I don't have a reference for it, but I recall Cisco, somewhere on their main site, does document ingress and egress configuration processing sequence.

[mlund · Accepted solution]

Here is one good explanation.

http://www.cisco.com/c/en/us/support/docs/ip/network-address-translation-nat/6209-5.html