Posted: 9/8/2008 11:43:32 AM EDT
| I'm helping a friend do some research so please bare with my lack of knowledge on the subject. You know how you can use DHCP in a DSL modem to assign an IP? Well, the setup he has at work forbids him to use DHCP. He is supposed to disable DHCP and make it "pass through IP" instead of DHCP." Any help would be AWESOME. We're behind on our schedule and I'm doing my best to help him. |
|
Yea thats kinda hard. The ISP expects a DHCP request so they know who has what IP and they don't assign two computers the same IP. The best bet is to get a router (or if the DSL modem allows it) so the router does the DHCP for the external IP and then he can hard code his IP settings for his internal network. Hopefully this will work out for him. You can get static IPs from some ISPs but they usually require a "business" line which is basically saying "you get the same exact service but we charge you more." That can get you a static IP but they may still want him to use DHCP to get it (maybe not). If you could explain the situation more that would help us find a solution. Is it a work computer? Why would work forbid DHCP? Is this something he can set to use DHCP on the DSL modem and then switch back to static IP at work? -Foxxz |
|
After thoughts... I figured more information should be given. It is a Westell modem with a static IP I'm talking about. It is not for personal use. It is the DSL backup for a bank branch. The guy who was supposed to be setting up the ASA (I still don't know much about them) that follows the modem said that DHCP has to be disabled and run a pass through IP. I hope the more information helped. Now, Foxx, I need to read what you wrote. |
|
I see your dilemma now. I don't know much about the modem you are using. You have two options. The first and best bet is to try and see if the modem can be reconfigured as a pass through by disabling NAT, firewall, etc on it. See if you can assign the static IP to a computer or ASA and ping out that interface. The modem may also have a DMZ function. The modem holds the IP but NATs all incoming traffic to something like 192.168.0.100 which would be assigned to the ASA. However, that complicates the ASA setup a little. If neither of these options work you may need to find a compatible modem that acts as a pass through/media converter. -Foxxz |
|
How to enable IP Passthrough on your Westell DSL Modem/Router. CAUTION. THIS EXPOSES YOUR COMPUTER TO THE WILD WILD INTERNETS WITH NO HARDWARE (NAT) FIREWALL PROTECTION. www.dslreports.com/faq/7073 |
This is brilliant!! (not you TPS) Put a bank system out of the Internet with no firewall....    brb, need free money. 
|
He's hooking the DSL modem into an ASA which is a current generation Cisco business grade firewall. -Foxxz |
BUT, we will forgive NimmerMehr for not knowing this, as, checking back in the thread, I don't see any overt reference to the fact that the ASA in question is actually a firewall. If you aren't keeping up with Cisco hardware, you wouldn't really have any reason to know that ASA is Cisco-speak for 'Adaptive Security Appliance', i.e. their current line of Firewalls. For that matter, I wish I didn't have to keep up with Cisco hardware! Cheers! (Off to troubleshoot MPLS issues in the UK, have to be in the spirit.) FluxPrism |