1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Multiple Static IP's with BT business bb

Discussion in 'Networks & Internet Connectivity' started by Illusion, May 21, 2008.

  1. Illusion

    Hitman

    Joined: May 31, 2007

    Posts: 867

    Hi Guys,

    New to this forum so Hi!

    Today I requested a block of 5 IP's from BT and I am having some trouble using them, this could come across as noobish so please take it easy on me if I am doing something blatently wrong.

    Now I was told by the person on the phone that I just had to reboot my router (Belkin 7633 at the time) and that it would automatically pick up the new IP details and voila, there I am.

    This did not happen.

    Calling BT back didn't get me anywhere, the girl on the phone didn't have a clue and was just putting me on hold all the time.

    I couldn't get the Belkin to work with a static IP so I have gone back to the awful BT Business Hub. Now after following the instructions on their website I have managed to get this sort of working. I will try and explain below:

    Internet//// ----(81.148.xx.xx) BT Hub ---- Local Network (left on private ips)
    ............................................|
    ............................................|------Debian Server on public ip 217.40.xx

    What confuses me is that the BT Hub appears to have one of the static IPs assigned to it aswell as the 81.148 address, forgive me for being stupid but I was under the impression I would just set the router as the first static IP in the range and use the rest for whatever I needed.

    The Deb server does indeed appear to be fully accessible to the internet but running simple commands on it like ping and whois queries doesn't get me anywhere, and google suggests this could be a routing issue because my router doesn't know where to send the reply packets.

    Could someone with some knowledge please shed some light on this situation, has anyone had any experience setting up multiple (or a single) static IPs with BT business broadband?

    Is it even possible to use the Belkin router as I despise the BT one?

    I can see this turning into a long post as I have so many questions to ask so I will stop here for now, any help would be GREATLY appreciated.

    Thanks in advance.
     
  2. m_cozzy

    Hitman

    Joined: Nov 13, 2005

    Posts: 677

    Location: Havant

    Oh dear bt business, I had the misfortune of using them a good few years back & left when they were unable to fix an ip fragmentation problem that developed overnight. I would seriously recommend moving... anyway..
    They did things in a funny way I seem to remember, so the routers external ip was dynamically allocated & you set the routers internal ip to the 1st one in the range they have given you.
    I have only ever used cisco gear whilst I was with them so i guess you would have to turn natting off on the belkin rouer.
    Run a tracert from the linux box to see where it is falling over.
    Looking at your diagram can either of the devices you have do a proper dmz to seperate from the lan?
     
  3. oldbag

    Sgarrista

    Joined: Oct 14, 2003

    Posts: 7,843

    Surely they issue you a block of IPs? Issue the first usable IP with subnet mask and gateway to the router and then use another IP from the block to the required machine. Wouldn't it be more secure to use PAT so at least the PC is protected by a Firewall?
     
  4. Rob7865

    Gangster

    Joined: Sep 4, 2006

    Posts: 307

    Location: Bristol

    HI
    What normally happens when BT issues you an IP block is you should be told your IP Range, Gateway address and Submask (255.255.255.248 - is normal for 5 addresses)

    You will then need to set your Router up using those details - for example:
    G/W Address from BT is used as your routers FIXED IP
    Submask - 255.255.255.248
    Some routers as cleaver enough to workout the IP Range from using the G/W address and submask.

    Then assign your client machines with one of the IP's from your allocated range

    Rob
     
  5. Illusion

    Hitman

    Joined: May 31, 2007

    Posts: 867

    Thats right, although the business hub has the natted internal range and a separate range for the IPs that have been allocated...

    To be honest I don't know, I just want eth1 on the debian server to have a public ip and eth0 an internal one, I'm not too clued up on setting this kind of thing up at the moment which is one of the reasons I am trying to do it.

    As m_cozzy said above the router continues to pick up a dynamic IP from BT, after looking around this is the norm it would seem, although I don't see why.

    Thanks Rob, this is what I originally intended to do, but I can't set my routers WAN IP statically as mentioned above.

    The printout from BT has the IP range and Subnet Mask, it also has a Router Port IP which is 217.40. something . something but not within the subnet of my IP's. Any idea what this is for?


    The connection does actually work at the moment with the BT Hub, the main reason I am posting is because I don't fully understand how!

    Again all help is much appreciated.

    Thanks
     
  6. mdjmcnally

    Wise Guy

    Joined: May 17, 2004

    Posts: 1,598

    This is the standard way that BT Multiple Static IP works, which is also the way that my Zen connection works.

    You are allocated a block of 8 Publlic IP addresses. for arguments sake 1.1.1.0/29 giving your

    1.1.1.0 as the network
    1.1.1.1 available
    1.1.1.2 available
    1.1.1.3 available
    1.1.1.4 available
    1.1.1.5 available
    1.1.1.6 as the routers Ethernet address
    1.1.1.7 as the Broadcast

    You do not know or care what the ADSL side of the router is. NAT is turned OFF on the Router so the Public IP on your ethernet is what goes out to the Internet. Your ADSL Router then connects as normal and is allocated an IP to the WAN by BT.

    You give the Debian Server an address of

    1.1.1.5/29 and set the DNS Server as 1.1.1.6 and DG of 1.1.1.6

    You then set the DNS for your public domain so that debianserver.yourdomain.co.uk points to 1.1.1.5.

    Hope this explains how it should work. This is certainly how it has worked at 40-50 sites for me.

    As has been pointed out this means that there is no firewall between the Debian Server and the Internet and you should get a firewall solution. I used to put in a firewall as 1.1.1.5 and then use that to NAT to my servers in the DMZ off my firewall. ie NAT 1.1.1.5 to 192.168.1.5 on the DMZ, 1.1.1.4 to 192.168.1.4 on the DMZ. I would use 1.1.1.1 as the WAN side of the Firewall and then Hide NAT outbound traffic from the Internal Network behind this address.

    If all you have is one Server then probably better to use 1 static IP and PAT on the ADSL box to redirect the services to the Server on the private IP behind the ADSL box.

    The Static IP is therefore on the WAN side of the ADSL Router and uses NAT/PAT to protect the server.
     
  7. Illusion

    Hitman

    Joined: May 31, 2007

    Posts: 867

    Thats a great post, thanks for the help.

    So if I change it to just a single static IP, will this be assigned to my router rather than how things are at the moment? This is what I originally wanted...

    Thanks
     
  8. Rob7865

    Gangster

    Joined: Sep 4, 2006

    Posts: 307

    Location: Bristol

    Illusion

    I take it your wanting to run a webserver of some sort? If all you want is 1 static IP, Would it not be easier and cheaper to set up a Dyndns account to handle the redirect of your dynamic IP address?

    Just a thought!
    Rob
     
  9. Illusion

    Hitman

    Joined: May 31, 2007

    Posts: 867

    I already have a dyndns account, it sucks. I cant use this with a domain name as far as I am aware.

    Cheers
     
  10. Rob7865

    Gangster

    Joined: Sep 4, 2006

    Posts: 307

    Location: Bristol

    If you have access to the DNS settings for your domain, you could set a CNAME record to point back to your DYNDNS URL - thus anyone who enters www.YOURDOMAIN.COM would be pointed in the direction of your DYNDNS URL and then onto your server....

    Just an idea!
    Rob
     
  11. m_cozzy

    Hitman

    Joined: Nov 13, 2005

    Posts: 677

    Location: Havant

    It sounds like you just need 1 static ip. Then you can port forward this onto your lan.
    Alternatively as mentioned absolutely ignore whatever appears on the adsl interface(wan) & set the routers lan ip to the public address they have given you. Ideally though you would then need another router to seperate the lan off on a private range, unless the routers you have a seperate dmz interface (doubt it)

    EDIT Reading again the linux box i guess is seperating your lan from the internet as you mention eth0 & eth1, so i assume this is also the firewalling/natting lan traffic. An iptables firewall will be fine for home use. Having said that I run a cisco 837 & asa5505 on my /29 from zen.
     
    Last edited: May 22, 2008
  12. mdjmcnally

    Wise Guy

    Joined: May 17, 2004

    Posts: 1,598

    Yes, if you have a single Static IP that would be assigned to your WAN interface when your ADSL router connects up. You then use NAT/PAT to direct services to the Linux box.
     


Share This Page