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The SBC/AT&T 5 Static IP packages are PPPoE. The Static IP Addresses are accessed via one PPPoE session.

The Router used has to be able to accept the subnet of IP addresses via the one PPPoE session and use them accordingly. Most of the less expensive Routers available will only do 1 to 1 NAT and access only one of the static IP's (the wan/gateway).

The Compatible routers (i.e. 5861, 2-wire 1800, 3546) can perform multi-nat, and/or apply the public IP's directly to computers.

SBC/AT&T bridges the subnet across 1 IP, your router takes up 1 IP, and there is the 1 broadcast IP, so in a class C range (which is what you get from SBC/Ameritech), you have 5 usable ip's (8-3=5)

The SBC/AT&T static package is only offered a single 5 IP block unlike other regions which can order larger IP blocks.

This is an example of a SBC/AT&T Routed Subnet with a total of 8 IP's 5 usable:

169.129.154.7 Broadcast (programmed in the RedBack, not useable by customer)
169.129.154.6 Router (WAN interface/Gateway)
169.129.154.5 Free for use on Lan(public/routable IP address)
169.129.154.4 Free for use on Lan(public/routable IP address)
169.129.154.3 Free for use on Lan(public/routable IP address)
169.129.154.2 Free for use on Lan(public/routable IP address)
169.129.154.1 Free for use on Lan(public/routable IP address)
169.129.154.0 Network (programmed in the RedBack, not useable by customer)

The usable Static/Public IP addresses are the 5 immediately below what your Router is assigned. The one before that and the one after the Router's IP complete the 8 IP block.

The WAN interface/Gateway is the only IP address that a Linksys, Netgear, SMC, D-Link Router would get/use. The last routable IP address is always assigned to the router.

An 8 IP subnet can also be called a /29 in regards to the Subnet Mask 255.255.255.248
The wan/gateway address is not in the same Subnet Mask as the /29 block 255.255.255.252

SBC/AT&T will provide registration information for the IP address block
Your billing name and subnet block will be in a ARIN entry. Use the link below for information to check and/or have the ARIN registration information changed:
I have a fixed IP how do I remove my private information from ARIN?

There is no difference between a static and dynamic installation on the customer end except for the router and it's configuration. You can easily do that yourself. You don't even need their equipment as long as you know what you are doing. On the SBC/AT&T end, it's a RADIUS entry and a different Redback assignment, all done in software. The installation charge for static accounts is a huge expense since the technician will configure the Router to NAT the static IP to the LAN, and use the Router's address as a gateway.

Other helpful information:
PPPoE with a Routed Subnet
This lets the Netopia do the PPPoE login and uses the public IPs on the Netopia's LAN.

Here's some other ways to setup the Netopia:
Initial Setup
IP Passthrough
Bridge Mode
3346 Technotes


Feedback received on this FAQ entry:
  • All of the netopia urls are invalid. Got a cached copy of the page somewhere?

    2011-11-25 22:40:14 (justbits See Profile)



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by geek See Profile
last modified: 2007-11-28 09:30:44