Port forwarding and port redirection

bogpsycho — Mon, 11 Mar 2019 22:50:44 GMT

Hello everybody ! I'm new at the ASA5500 domain. I have a question: How can I redirect traffic coming on a port to a machine inside the lan listening to another port ? I would like to use ASDM.

Thank you in advance.

Port forwarding and port redirection

llamaw0rksE — Fri, 06 Apr 2012 14:26:15 GMT

Will assume for your example that external users corporate can only use port 80 outbound from their network. THey need to access port 7777 behind the asa on a private inside host.

object network extuser

host 24.223.23.16

object network PCwith_Server

host 192.168.2.12

object network Nat4portforwardingService

host 192.168.2.12

object service specialfunction

service tcp destination eq 7777

object service corporate_port

service tcp destination eq 80

object-group catchall

service-object service special function

sercive-object service corporate_port

NOTE: I create the two service objects ports involved and lump them into a group object for the acl rule. It is still not clear in my mind how the asa actuallyhandles acls and nat in order due to a poorly documented support and unnat process evident in packet tracing. Normally according to docs ACLs are done first then nat, so one would expect in our example that port 80 only needs to have an outside ACL rule. Due to experience I put both in the acl rule.......

-----------------------------------------------------------------------------------

ideally only need acl for port 80

access-list outside_access_in extended permit object corporate_port object extuser object PCwith_Server

to be safe this is what I use......

access-list outside_access_in extended permit object-group catchall object extuser object PCwith_Server

(for any external user replace 'object extuser' with 'any'

-------------------------------------------------------------------------------------

object network NAT4portforwardingService

nat (inside,outside) static interface service tcp 7777 www

---------------------------------------------------------------------------------------

topic Port forwarding and port redirection in Network Security

Port forwarding and port redirection

Port forwarding and port redirection