US Telco Support > AT&T > AT&T Midwest > Is it possible to keep dynamic IPs while having static IPs?

Is it possible to keep dynamic IPs while having static IPs?

reply to MaryAnnB
in a way you can, but just because you have a dynamic IP does not equal privacy/security. your WAN IP will be dynamic, your LAN IPs would be NAT'ed private IPs, and your machiens requiring public statics could either have them directly assigned or be setup on a NAT ip and map the public statics to them.

i have 5 statics of 65.81.xxx.yyy assigned to various servers, but most computers at the shop appear to the world as the dynamic ip of usually 70.x.x.x which changes whenever the modem connection is reset or ATT decides to change it.
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Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

quote:

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i have 5 statics of 65.81.xxx.yyy assigned to various servers, but most computers at the shop appear to the world as the dynamic ip of usually 70.x.x.x which changes whenever the modem connection is reset or ATT decides to change it.

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i have my 3347 control PPoE. if you use PPPoE/A on the linux box, then it does ALL your routing. you modem would be setup for bridge mode, connected to one LAN card on the linux box, then out the other LAN is the connections to all other devices. nothing else will work between the linux box and the modem unless your modem handles the PPoE.
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Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

David, so does this mean I cannot use bridged mode to dial PPP from my linux box to Netopia 3347 to make use of the dynamic IP and my static IPs?

no, it means if you need to use PPoE on the linux box, then your linux box MUST be the router for the network. how you configure the backside(LAN) of it is up to you and your network guru. i have never touched linux in my life, so i cannot advise you on how it would be configured, just that it can do what you ask.
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Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

Thanks David.

I do not have problems from the LAN side when I use PPP to authenticate.

All I have to do to add static IPs is "ip addr add $ip dev ppp0" when ppp links comes up and tear it down when it is disconnected. And add also a route with iproute. No big deal.

However, AT&T tech support told me either you can have dynamic IPs or static IPs.

I doubt they knew what they were talking about. There were also various docs mentioning ROUTED SUBNETs and this was not clear.

So the question still remains:


Can I get dynamic IPs while doing PPP authentication from linux box (PPP on computer/ Bridged Mode) at the same time using static IPs?


I will appreciate someone who has done/tried that can chime in.

Mary

to be clear, ATT(in some areas) will provide to the WAN IP of your device(Linux box/modem/router/etc) 1 dynamic IP and then from that route to you 6 public IPs. 1 of these is to serve as your LAN default gateway, 5 are usable for devices. you can set your network up so that you use the publics for some devices, and the others use NAT behind the public WAN IP of your Linux box. so tehrefore everytime you disconnect your PPoE session, that WAN IP should change.

so to answer your question again, YES you do get 1 dynamic IP and your public static IPs on some parts of the ATT network. i did not realize earlier you were in the midwest forum, i can't remember if the WAN ip changes there or not like it does here in the old Bellsouth region. it seems like it does, but i can't swear to it. i know some parts of ATT MW do have routed subnets, but i think that is only in areas that do not do PPoE authentication.
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Lack of Preparation on YOUR Part does NOT Constitute an Emergency on Mine!

Thanks David,

AT&T support still insists you can't have it both ways at the same time. Either static or dynamic.

Mary