BT Broadband - Static IPs

Ironic Namesake

Ironic Namesake

Ironic Namesake

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I've just got a block of static IP addresses for our office, I've been given a block of 8 :

You've ordered a range of Static IP addresses, which contains 8 addresses from ***.**.**.185 to ***.**.**.189. Three of these are reserved:

* network address: ***.**.**.184
* router/Hub address: ***.**.**.190
* subnet mask address if you have 5 Static IP addresses: 255.255.255.248
* subnet mask address if you have 13 Static IP addresses: 255.255.255.240

I've never used Static IPs , so not sure how I go about setting these up/assigning these to a machine? I spoke to BT and they just told me they don't give any support on static IPs , he was addament that the router would still remain wit a dynamic IP, doesn't that defeat the point?
 
nope. The router can have it's own subnet between you and the ISP. The IPs you have are still publically routable and don't require NAT.
E.g My network card can have an IP of 10.0.0.1 and an ip of 192.168.1.1 and it can route traffic to both subnets. Just the dynamic one won't be used for anything much.
 
I've tried setting a static IP on the router but it still seems to get assigend a dynamic .

How do I go about assigning these and setting up the router?

I'm not too clued up on networking :p
 
One would argue if you're not clued up on networking you shouldn't be doing this :p

Basically you assign the IPs to machines, traffic is then routed to them by the router. On which you will need to configure a route to the IP address range you have been given. The router itself shouldn't need one on it's WAN interface, it will need one on it's LAN interface to communicate with other devices in the range.
the IPs should be given to any device that needs to be accessed from the Web. However this requires manual routing configuration and also presents security issues that need to be addressed.
My best advice is if you don't know what you're doing, get someone who does to set it up and then explain why they did what they did. Though if you're not used to networking it probably won't make much sense to you.
 
We don't have anyone that can do it unfortunately - I'm the only one who even knows how to access the router setup :p
I'm sure I'll be able to figure this out - the only things I'm really confusd by are these WAN settings in the router (I've never had to change them before, as was always dynamipc IP before) :

1. IP Address (here I used this : router/Hub address: ***.**.**.190)
2. Subnet Mask (here I used this : subnet mask address if you have 5 Static IP addresses: 255.255.255.248)
3. Default Gateway (here I don't know what to use)

I only really need one system with a static IP now , so I used :
1. IP address (used one of the 5 IPs in the range)
2. Subnet mask (same as above 255.255.255.248)
3. Gateway (here I used 192.168.100.2, internal IP of router)

Does that look about right? When I sue those settings the internet on the PC I configured doesn't work :p so I guess I've gone wrong somewhere.
 
You have to do a lot more than just add the IPs to machines and the router. first of all you need a router tha can support routing without NAT properly or supports 1:1 NAT pools. Something like a Cisco 877.

Have you configured NAT and static routing before?
 
Change the Gateway address - Remember, the Gateway is always the address of the router needed to get out to the other subnet, in this case the other subnet is the WWW.

Rob
 
Ah, takes me back to when I was figuring out how subnetting worked!

Basically the network address (x.x.x.184) is the address for your block & is not usable.
The gateway (x.x.x.190) is the router at the ISP & is unusable.
Therefore out of the 8 static IPs provided by your ISP, only 5 are usable.

So:

Use one of x.x.x.185, 186,187,188 or 189 as the IP Address
255.255.255.248 as the Mask
x.x.x.190 as the Gateway

Use the DNS provided by your ISP

& you should be in business!
 
Last edited:
Skidilliplop said:
You have to do a lot more than just add the IPs to machines and the router. first of all you need a router tha can support routing without NAT properly or supports 1:1 NAT pools. Something like a Cisco 877.

Have you configured NAT and static routing before?
Click to expand...

We're using a standard Belkn router, so no idea if it supports this.
I thought it was fairly simple to have a static IP :o
 
Last edited:
JonnyT said:
Ah, takes me back to when I was figuring out how subnetting worked!

Basically the network address (x.x.x.184) is the address for your block & is not usable.
The gateway (x.x.x.190) is the router at the ISP & is unusable.
Therefore out of the 8 static IPs provided by your ISP, only 5 are usable.

So:

Use one of x.x.x.185, 186,187,188 or 189 as the IP Address
255.255.255.248 as the Mask
x.x.x.190 as the Gateway

Use the DNS provided by your ISP

& you should be in business!
Click to expand...

Cheers will give that a go ... those settings for the router or PC?
 
Why do you want this?
You dont really want to be giving pc's on the lan a routable ip address and the router you have doesn sound like its capable of doing a proper dmz with publicly accessable servers ?
 
Your router won't handle it.

Why do you need all these IPs? It might be much cheaper and easier to use port forwarding.

How Many People/PCs in your office and what services are you going to be hosting?
 
We only actually need one static IP, but BT gave us a block of 5! It is to connect to a database server on our network - to update stock records/order details onto an ecommerce website

We have around 8 PCs in the office, but only one need a static IP - so I guess if we just had a static IP on the router we can forward the port to the database server and that's it?
 
Not that it helps you but it should never be setup that way around :( your machines should be setup to periodically submit data to the server...
 
It would appear that BT have done their normal up-selling/miss-selling.

I found the same problem at an accountants when I went in to sort out their problems. BT just asked them how many PCs they had and then sold them an expensive block of IPs to match. By the time I got there the damage was done and they had to wait until the contract expired before they could drop back to the single static IP they actually needed.

From memory if the router was left to pick up an IP via DHCP it was assigned an dynamic address rather than picking up one of the assigned static IPs. I think I just configured one of the assigned addresses (not the first) as a static address on the router and then used NAT.

Do you have a server? If you have it could make a difference to how the LAN needs to be configured.
 
As above.

Static IP isn't the only way, you can do it using DNS which is a far neater way of doing it. That way you can change IPs or even ISPs without having to reconfigure the service at their end.
It'd be worth while asking if it can be done using an FQDN instead of an IP address. Which it probably can if it's been designed sensibly. Another option would be VPN aswell. All of which are arguably easier and more secure for a novice to setup than a routed public DMZ
 
bremen1874 said:
It would appear that BT have done their normal up-selling/miss-selling.

I found the same problem at an accountants when I went in to sort out their problems. BT just asked them how many PCs they had and then sold them an expensive block of IPs to match. By the time I got there the damage was done and they had to wait until the contract expired before they could drop back to the single static IP they actually needed.

From memory if the router was left to pick up an IP via DHCP it was assigned an dynamic address rather than picking up one of the assigned static IPs. I think I just configured one of the assigned addresses (not the first) as a static address on the router and then used NAT.

Do you have a server? If you have it could make a difference to how the LAN needs to be configured.
Click to expand...

We were advised to get a Static IP , so just called BT and arranged this - not expensive at all (£5 per month :p )

We have a server which is SBS 2003 taking care of Exchange only, its not doing anything else.

We do have DynDNS set up on the router at the moment which seems to work fine, we were just told to get a static IP instead and not use this - not sure for the reason behind this.

I assumed if I had static IP, the router would just be always assigned the same IP when connected to ADSL, not thati t was this involved.

If I call BT and change down to just 1 static IP, would this make it fairly simple or still a pain to resolve?
 
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