Accessing the internet with a single static IP

[eyeball]

Hi all, heres a good one for you....

i have a a BT line with a single static ip

a zyxel router with NAT capabilities (with only a single LAN interface)

a GTA GNATbox (hardware firewall) with 3 interfaces (internal , external, and dmz)

the line i have is ADSL

i have a single static address and would like to access the internet using this static address. simple? thats what i thought...

on the router i can manually specify a static address but i cant get out to the internet i get destination host unreachable. i think its because there is nowhere on this device to specify a default gateway so the router doesnt know what to do with traffic.

if i switch on DHCP on the router i am given an address which is something in the 81.x.x.x range - nothing like my static address, but i can get to the internet

so i phoned BT and asked them if they could create a DHCP reservtion for my address, they said no lol.

can anyone think of a possible configuration or way to get this working?

thanks

Edited January 27, 2007 by eyeball

[Deman]

Sorry but your post is confusing me

You have a static IP given to you by your ISP (generous of them) and you want your PCs on the network to all use it, or to all have public static IPs?

i phoned BT and asked them if they could create a DHCP reservation for my address, they said no

If your ISP is giving you a static IP then you wouldn't need to ask them for a DHCP reservation? And since they said no, i'm wondering whether the IP they give you is a dynamicly assigned one.

on the router i can manually specify a static address but i cant get out to the internet i get destination host unreachable. i think its because there is nowhere on this device to specify a default gateway so the router doesn't know what to do with traffic.

It could be because the IP address you're setting isn't recognised by your ISP. So you either aren't getting a static IP or the static IP is automatically given to you by your ISP and there's no configuration required on your router

Failing that of course, the address you're setting is it's internal address which puts it out of whack with your home network

Anyway what's wrong with using DHCP/local static IPs for the local network and using port forwarding for any servers you've got running?

[eyeball]

hey thanks for the reply

yes i want all pcs behind the router and firewall to be nat'ed to the single public ip,

the reason i had to ask for a DHCP reservation is because as i said i am dynamically assigned a completely different ip when i switch on DHCP, i need to use the static one as i need A and MX records pointing to this ip.

and i know the ip is correct as to be truthful i have had it working but i had to use a second public ip and fully featured nat. but the point is i want to get it working with one ip if possible (cos buying only one ip from my isp is a lot cheaper )

i really dont think what im asking is possible with the equipment i have but who knows someone may have come across a similar setup before

thanks again

[LLXX]

i think its because there is nowhere on this device to specify a default gateway so the router doesnt know what to do with traffic.

Get a better router, lol.

Even the cheapest ones these days should have those capabilities.

Edited January 27, 2007 by LLXX

[Deman]

What you're after is a standard setup, it's just connecting with a static IP

I haven't really dealt with static IPs with xDSL routers so am not really too sure as to what's expected in the configuration.

That aside I would of thought that any standard DSL router would be able to do the job, are you able to post up the model number of the router and/or screen capture of the appropriate page? (blank out the login details of course)

You mentioned it worked using a second public IP, what was different about the second from the first? Anything in the configuration or was it just a different number

[eyeball]

its a zyxel 600 series router and the way i had it working with 2 ips was as follows:

the lan interface of the router had the ip 217.xxx.xxx.xx8

the external interface of the gnatbox had 217.xxx.xxx.xx7 and a gateway of the routers lan interface

and then on the internal interface i had my network (192.168.16.0/24)

i had nat turned off completely on the router so basically all traffic was just being routed and passed through to the firewall and then remote access filters and nat rules dealt with everything from there.

i think that with the current device i have it IS impossible as without a gateway the router wont have a clue what to do with traffic.

maybe its possible with some static routes in place? but iv thought about it for ages and i cant come up with anything

doesnt matter if we cant do it ill have to stick with an ip range (or buy a better router) lol

thanks

Edited January 27, 2007 by eyeball

[Deman]

Well what you could do is put the gnatbox on the internal network give it an internal address and turn NAT on the router so you've got Internet - Router - Gnatbox - LAN

[eyeball]

hey deman

thats how i had it working before but as i described i had to use 2 ips cos the crappy router has nowhere to specify a gateway, the router was the gnatbox's gateway so it worked.

thanks for the help though but i think im gonna get a better router to save on a lot of problems in the future.

thanks