NAT without DHCP?

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NAT without DHCP?

Tech Ranger
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NAT without DHCP?

I am now for the first time setting up a business network connection to the Internet via AT&T SDSL. Today an Efficient Networks 5851 router was installed. The service that AT&T provides involves 5 public IP addys. I am not going to use the default setup. I plan to use NAT with port mapping to direct pcanywhere traffic to the appropriate server. The Covad tech configured the router with a static WAN IP addy and a static LAN IP addy. I enabled NAT. If I don't want to use DHCP, is there any reason I cannot simply assign whatever LAN IP to the router I choose, as long as it's on the same subnet as the boxes on the network, which I will likewise assign static private IPs? There is no need to use DHCP in order to use NAT, is there?

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03-26-03 02:47 AM

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edmonds_robert
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You are correct. In fact, using DHCP in conjunction with NAT makes it harder, not easier. I'm not familiar with the Efficient Networks equipment, but in general, to do NAT the computers on the inside don't even have to be on the same subnet as your router/firewall. The firewall just has to know where it is. I think you should have no problem getting this to work.

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03-26-03 02:34 PM

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mindmesh
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I work with Efficients all the time. You don't need DHCP.. We like it because most EU's are dense and it's easier to have them do the least amount of work as possible..
if you have public IP's you can just do one to one mappings ( public IP mapped to Private Ip's). Good luck..

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03-26-03 02:44 PM

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Tech Ranger
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I was assigned 5 static public IPs. Although all my boxes will have private IPs, can I choose any of the 5 IPs to issue to a remote user to connect to the network to make a pcanywhere connection using port mapping? I wouldn't use the WAN IP of the router, would I? Or does it matter?

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03-27-03 12:24 AM

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darthfeces
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there you're ip's ....assign them as you will.
put a pix 501 behind it and nat off that ..... you still have to account for your next hop's route either static or dynamic

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03-27-03 02:35 AM

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mindmesh
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quote:
Originally posted by Tech Ranger
I was assigned 5 static public IPs. Although all my boxes will have private IPs, can I choose any of the 5 IPs to issue to a remote user to connect to the network to make a pcanywhere connection using port mapping? I wouldn't use the WAN IP of the router, would I? Or does it matter?

You can do this both ways.. You can map ports from the WAN or you can keep the privates and assign the publics. For example:

sys addserver 192.168.1.XXX tcp 5631
sys addserver 192.168.1.XXX udp 5632
sys addserver 192.168.1.AAA tcp 5633
sys addserver 192.168.1.AAA udp 5634
This just maps the ports but you have to configure the software to use ports other then 5631 /5632.

rem addhostmapping 192.168.1.1 192.168.1.5 66.219.xxx.xxx <dslip>

What this does is makes you private IP's public. NAT just forward all ports from the public IP to the private IP while keeping everything else NAT'ed.

Both ways work you just have to decide which is easiest for you. Hope this helps a little.

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03-27-03 01:07 PM

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Tech Ranger
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Thanks. It sweems that port mapping can be done from the Web GUI. Do you know whether 1 to 1 IP mapping requires use of the CLI?

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03-28-03 01:34 AM

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