topic Re: PIX doing NAT and routing behind ADSL modem in Network Security

PIX doing NAT and routing behind ADSL modem

ddicky — Fri, 21 Feb 2020 06:44:19 GMT

I have an adsl mdem connetion connecting to a modem which is unable to do NAT and routing.I understand that PIX will be able to do NAT routing for internet sharing.Pls advise as I don't have any fixed IP addresses alllocated from my ISP to me.

Re: PIX doing NAT and routing behind ADSL modem

mhoda — Sun, 11 May 2003 07:42:18 GMT

If the modem is not doing the nating then PIX has to. So, if the pix outside is getting the dynamic ip, then you can do the translation as follows for the inside net to be able to go to internet:

nat (inside) 1 0 0

global (outside) 1 interface

So as you can see, its doesn't matter what's your ip gets assigned dynamically to the outside interface, Then obviously you will nee a default route as follows:

route outside 0 0 gateway_address <--This address should be provided by your ISP. I hope this helps !

Thanks,

Mynul

Re: PIX doing NAT and routing behind ADSL modem

ddicky — Sun, 11 May 2003 14:27:38 GMT

well,now I am starting to get some idea.But unfortunately the portion you mentioned about the gateway _address provided by the ISP,I don;t have cause I don't have any IP adress allocated as my connection is dial-up using DHCP.Any further advise.

Beside you mentioned about

Global(outside)1 interface ,which interface?

thks

Re: PIX doing NAT and routing behind ADSL modem

mostiguy — Sun, 11 May 2003 17:27:52 GMT

global (outside) 1 interface

refers to the outside interface. it means to use the ip address of the outside interface for PAT

ip address outside dhcp setroute

tells the pix to be a dhcp client on the outside interface, and to use the route option it receives in the dhcp lease as its default gateway.

that should do it

Re: PIX doing NAT and routing behind ADSL modem

ddicky — Tue, 20 May 2003 09:52:22 GMT

Well,my PIX were unable to get the IP address from ISP,i had monitor from the PIX monitoring system.BTW if i would using the DHCP setroute,there is no option for me to set my username and password for my ADSL connection athentication.any adivse.

Re: PIX doing NAT and routing behind ADSL modem

thompson — Wed, 21 May 2003 14:10:45 GMT

Your IOS needs to be 6.1 at least, ideally 6.2.

Th following will create a PPOE dial out with your ISP.

ip address outside pppoe setroute

vpdn group dan request dialout pppoe

vpdn group dan localname

vpdn username password

You may or may not need to set an autentication type. Try it without, if it doesn't work call the ISP and ask what type of ppp authentication they support the command to set it is ...

vpdn group dan ppp authentication

'dan is only a keyword