User comments on ISPs
  >> PlusNet plc

Register (or login) on our website and you will not see this ad.

  Print Thread
Standard User mattewan
(regular) Wed 25-Jul-12 08:38:56
Print Post

Configuring a netblock on plusnet

[link to this post]
Hey guys,

I had a static IP on my business line with plusnet, which I have had with them for years.

Recently I have needed an additional IP for to assign to other servers we have on-site, which couldn't be solved by using NAT.

I requested a 4 IP Netblock from plusnet, and at the time I knew that two of those IP addresses would be "lost", the broadcast and the gateway IPs.

My Range is: <- Gateway <- First IP <- Last IP <- Broadcast

Now currently I'm using a linksys AM200 which, as far as i know, I have no way to configure without the modem stealing an IP, unless i get one of our servers to do the PPP authentication and get the IP directly.

Am I right in thinking that if I get one of these: then I will be able to have to connect a standard switch, not router, to that modem and assign to one server and to the other, using a netmask of on both.

I understand that if I then wanted nat, due to the lack of a router, I would have to get one of the servers with a routable IP to perform NAT for the rest of the network.

My second problem is the gateway....

I am having weird issues. Currently I am letting the modem just get standard dhcp and it gets the following config:


This is strange because on my plusnet control panel it specifically states that is my gateway, and when I have configured proper dedicated connections in the past the usual rule of thumb is that the first IP is the gateway, although sometimes they configure the last usable ip as the gateway. I understand that it can be any ip, apart from the broadcast, but usually it is the first or last routable ip.

Now I have an issue setting the gateway on my connection, if on any of my linux servers i configure as an IP then set the gateway as i get:

inet addr: Bcast: Mask:

route add default gw
SIOCADDRT: No such process

I'm a bit confused as to why I can't set the 216 address as the gateway

Standard User camieabz
(sensei) Wed 25-Jul-12 10:41:08
Print Post

Re: Configuring a netblock on plusnet

[re: mattewan] [link to this post]
When I had an 8-block with Zen, three were assigned to WAN, LAN (gateway) and broadcast, with five for local nodes.

With a 4-block, one is useable by nodes, with the same three allocated to WAN, LAN, Broadcast. Or that's how I see it.

4 IP block provides 2 usable IP addresses (1 for the router and 1 for servers, PC, etc.)

I presume you could setup DHCP for one IP, and the PCs could use it, while you configure the other IP for a server. Either that, or it's fine for using a non-NAT setup.

~ Camieabz ~

All Connection Data ~ Some plusnet links

mod'er·a'tion n.
Synonyms: temperance, restraint, modesty.

Edited by camieabz (Wed 25-Jul-12 10:41:27)

Standard User techguy
(committed) Thu 26-Jul-12 20:07:48
Print Post

Re: Configuring a netblock on plusnet

[re: camieabz] [link to this post]
A /30 allocation is not really suitable for what you are looking to do.

How many servers and PCs do you have?

Virgin (ADSL) => Namesco => Newnet => O2 => Plusnet => Zen => Newnet => Zen Lite 8000
Note: I don't lay turf for anyone. astro or otherwise, all views and opinions expressed are my own based on experience.

Register (or login) on our website and you will not see this ad.

  Print Thread

Jump to