i have a site where users are connected to a switch (dummy) and then to a modem that deploy DHCP (private ip address, private DNS,...) to access internet. in this case the modem is doing the natting (192.168.1.0 to public ip)
now i have a new set up to work on, where users will be connected to 3560 switch -> asa 5505 -> 881 ISR -> modem (connected to internet).
all what i can think about is to give the users DHCP from a pool on the switch and do nat on the firewall and on the router.
In this case the 881 router outside interface will have an ip address acquired from the modem.
i cannot figure it out how the users will connect to internet !!!!!!!!!
1- from where they will get the DNS ip.
2- can the router will get the DNS from the modem.
** can i nat the ip of users to the outside interface of the firewall, then this natted ip will be natted also by the router to the DHCP ip.
will this work ? Is there any other way?
i mean there will be 3 natting process (firewall, router, modem), i think this will slow down the connection, process,,,,,,,
Sorry for being silly.
Thank you for your help in advance.