🚀 go-pugleaf

Alex wrote:
> 
> Id like to change my IP - it`s remained the same for ages, I`m dialling up
> using linux.
> 
> I`m sure it`s a matter of adding a pppd option; I tried ipcp-accept-local
> but my IP number hasn`t changed.
> 
> Any ideas?

Demon give you a fixed IP, i.e. their PPP server always dishes out the
same one when you sign on as the same user. So you tell pppd to get the
IP dynamically, which is correct - and Demon always gives you the same
one, which is also correct. Most people, including me, see this as a
positive advantage of using Demon, who are the only ISP I am aware of
who do this. Most do not have enough IP addresses to go round.

What is it you do not like about your address? 

If you really like your address changing, use another ISP and it will.

Ipcp-accept-local isn't required in most cases, you just don't specify a
local IP address and it accepts the one from the server. Sometimes you
need "noipdefault" but I have never seen this with an ISP, only a server
at work with a possibly dubious configuration.

Or am I missing something fundamental here?

Regards, Ian

Demon tech support reckon it is possible via Windoze, if you change the
connectoid to read "server assigned IP address" in the server types. So I
guess it should be possilbe as well via Linux...

hmm!


Ian Northeast <ian@house-from-hell.demon.co.uk> wrote in message
news:390890CE.A8F3240D@house-from-hell.demon.co.uk...

>
> Demon give you a fixed IP, i.e. their PPP server always dishes out the
> same one when you sign on as the same user. So you tell pppd to get the
> IP dynamically, which is correct - and Demon always gives you the same
> one, which is also correct. Most people, including me, see this as a
> positive advantage of using Demon, who are the only ISP I am aware of
> who do this. Most do not have enough IP addresses to go round.
>
> What is it you do not like about your address?
>
> If you really like your address changing, use another ISP and it will.
>
> Ipcp-accept-local isn't required in most cases, you just don't specify a
> local IP address and it accepts the one from the server. Sometimes you
> need "noipdefault" but I have never seen this with an ISP, only a server
> at work with a possibly dubious configuration.
>
> Or am I missing something fundamental here?
>
> Regards, Ian

In article <8ea6aj$oqe$1@gxsn.com>, Alex <noos@isys.demon.co.uk.nospang>
writes
>Demon tech support reckon it is possible via Windoze, if you change the
>connectoid to read "server assigned IP address" in the server types. So I
>guess it should be possilbe as well via Linux...
>
Yes you can certainly do that but the IP you are assigned is the same
every time.

-- 
Martin Liddle, Tynemouth Computer Services, 27 Garforth Close, 
Cramlington, Northumberland, England, NE23 6EW.
Phone: 01670-712624.  Fax: 01670-717324.

Alex wrote:
> 
> Demon tech support reckon it is possible via Windoze, if you change the
> connectoid to read "server assigned IP address" in the server types. So I
> guess it should be possilbe as well via Linux...

Yes, it is indeed possible to have Linux behave exactly like Windows
when you say "server assigned IP address". In every Linux dialup tool I
have seen it is the default, as it is in Windows, because it is correct
in 90% of cases. You do not give pppd a local address, so it gets one
from the server. The only cases I have seen where it was not correct
were PPP servers on private networks, not ISPs, where the normal cause
is the PPP server's being incorrectly configured. Such gross
configuration errors are uncommon with ISPs, as they go out of business
if their customers cannot connect.

As I pointed out, if you use Demon and request a dynamic IP address, you
will get one. It will be the same every time, because part of the Demon
service is to give you a fixed IP address.

I think we are failing to get at your actual problem. Why do you want
your IP address to change? I can see no possible benefit.

Regards, Ian

PS if Demon tech support really told you this I think someone needs a
little instruction in how their service operates.

Alex wrote:
> 
> Demon tech support reckon it is possible via Windoze, if you change the
> connectoid to read "server assigned IP address" in the server types. So I
> guess it should be possilbe as well via Linux...
>

If you use Windows you will see exactly the same effect - the IP address
will be the same every time.

Fair enough - I just thought I might make my connection more secure having a
dynamic IP.


Ian Northeast <ian@house-from-hell.demon.co.uk> wrote in message
news:3909EA4A.3A2E580C@house-from-hell.demon.co.uk...
> Alex wrote:
> >
> > Demon tech support reckon it is possible via Windoze, if you change the
> > connectoid to read "server assigned IP address" in the server types. So
I
> > guess it should be possilbe as well via Linux...
> >
>
> If you use Windows you will see exactly the same effect - the IP address
> will be the same every time.

Alex wrote:
> 
> Fair enough - I just thought I might make my connection more secure having a
> dynamic IP.

To an extent. But for better security you want to look at the kernel
firewall (ipfwdadm in kernel 2.0.x, ipchains in 2.2.x) and tcp-wrappers
(using /etc/hosts.deny etc.). 

Regards, Ian

In article <390AEFC0.95819F85@house-from-hell.demon.co.uk>,
	Ian Northeast <ian@house-from-hell.demon.co.uk> writes:
> 
> To an extent. But for better security you want to look at the kernel
> firewall (ipfwdadm in kernel 2.0.x, ipchains in 2.2.x) and tcp-wrappers
> (using /etc/hosts.deny etc.). 

I thought that there was a small but possible chance of smtp email going to
the wrong person due to the use of dynamic ip, making static ip safer?

-- 
Peter Chant 
pete@neither.demon.co.uk

Peter Chant <pete@petezilla.co.uk> wrote:
>
>I thought that there was a small but possible chance of smtp email going to
>the wrong person due to the use of dynamic ip, making static ip safer?

Doing SMTP with dynamic IP is a colossal bodge anyway - you'd need to have
your hostname listed as the most-favoured MX, and use dynamic DNS with a 
very short TTL to make sure that your hostname pointed to where you really
were.  Probably ETRN as well, although Demon's existing in-house mechanism
might be usuable.

And yes, there's still a chance of a connection going to the wrong box.

Regards,
Tim.

Tim Franklin <tim@leaphome.pelican.org> wrote:
> Peter Chant <pete@petezilla.co.uk> wrote:
>>
>>I thought that there was a small but possible chance of smtp email going to
>>the wrong person due to the use of dynamic ip, making static ip safer?

> Doing SMTP with dynamic IP is a colossal bodge anyway - you'd need to have
> your hostname listed as the most-favoured MX, and use dynamic DNS with a 
> very short TTL to make sure that your hostname pointed to where you really
> were.  Probably ETRN as well, although Demon's existing in-house mechanism
> might be usuable.

Indeed it would probably only be useable with something like Demon's set
up. Where the only MX records point to the ISP's machines. There would
be less risk of confusion if the dymanic DNS and the MX machines are
sat on the same piece of ethernet.

In article <0d21f8.np1.ln@anacon.demon.co.uk>,
	Mark Evans <mpe@anacon.demon.co.uk> writes:
> 
> Indeed it would probably only be useable with something like Demon's set
> up. Where the only MX records point to the ISP's machines. There would
> be less risk of confusion if the dymanic DNS and the MX machines are
> sat on the same piece of ethernet.

What are the advantages for an ISP in providing dynamic IP's? Does it 
mean they give customers addresses from the private network address range
and masquerade, or do they just allocate dynamically a small pool of IP
numbers?

-- 
Peter Chant 
pete@petezilla.co.uk

Peter Chant wrote in message <8fa0i8$tb3$1@phoenix.fire>...
>In article <0d21f8.np1.ln@anacon.demon.co.uk>,
> Mark Evans <mpe@anacon.demon.co.uk> writes:
>> 
>> Indeed it would probably only be useable with something like Demon's set
>> up. Where the only MX records point to the ISP's machines. There would
>> be less risk of confusion if the dymanic DNS and the MX machines are
>> sat on the same piece of ethernet.
>
>What are the advantages for an ISP in providing dynamic IP's? Does it 
>mean they give customers addresses from the private network address range
>and masquerade, or do they just allocate dynamically a small pool of IP
>numbers?
>


One advantage is that the not-modems can be assigned 
IP addresses.  The IP you get depends on the not-modem 
you connect to which is about as simple and effiecient as 
you can get.

I don't know of any ISPs that assign from private ranges 
as this is more complex than assigning from proper address 
ranges.

Jon Plews.

Peter Chant <pete@petezilla.co.uk> wrote:
>In article <0d21f8.np1.ln@anacon.demon.co.uk>,
>	Mark Evans <mpe@anacon.demon.co.uk> writes:
>> 
>> Indeed it would probably only be useable with something like Demon's set
>> up. Where the only MX records point to the ISP's machines. There would
>> be less risk of confusion if the dymanic DNS and the MX machines are
>> sat on the same piece of ethernet.

>What are the advantages for an ISP in providing dynamic IP's? Does it 
>mean they give customers addresses from the private network address range
>and masquerade, or do they just allocate dynamically a small pool of IP
>numbers?

Most do the latter, the former is really annoying.
The main benefit is better use of IPs, with static IP, you need one
per customer.
With dynamic, it can be one per customer online.

Acquiring large blocks of static IP blocks can be hard these days AIUI.

-- 
http://inquisitor.i.am/    |  mailto:inquisitor@i.am |             Ian Stirling.
---------------------------+-------------------------+--------------------------
He who lives in a glass house should not invite he who is without sin.

Peter Chant <pete@petezilla.co.uk> wrote:
>
>What are the advantages for an ISP in providing dynamic IP's? Does it 
>mean they give customers addresses from the private network address range
>and masquerade, or do they just allocate dynamically a small pool of IP
>numbers?

The latter, usually.  Although people like Freeserve, who give you a lot of
access to Freeserve's proxies and not much access to the Internet, could
possibly get away with masqerading.

The advantages to the ISP is that they don't need as many IP address (hint:
Demon (and others) have a lot less 'modems' than subscribers), and that they
can assign a specific IP to a specific modem (or specific pool to a specific
NAS, etc), which makes their internal routeing *much* easier.

Needing more addresses doesn't cost ISPs as such, but they do have to justify
it, and it's not easy.  (It's not that easy to justify addresses for anything
these days - that's one of my hats - but getting allocations for static
dialups is very much the proverbial blood / stone scenario).

Internal routeing isn't a problem for ISPs which have all their dial-up kit
in one location, but one for one with several locations (such as Demon), it's
non-trivial.

Regards,
Tim.

In article <8fa0i8$tb3$1@phoenix.fire>, Peter Chant
<pete@petezilla.co.uk> writes
>In article <0d21f8.np1.ln@anacon.demon.co.uk>,
>       Mark Evans <mpe@anacon.demon.co.uk> writes:
>> 
>> Indeed it would probably only be useable with something like Demon's set
>> up. Where the only MX records point to the ISP's machines. There would
>> be less risk of confusion if the dymanic DNS and the MX machines are
>> sat on the same piece of ethernet.
>
>What are the advantages for an ISP in providing dynamic IP's? Does it 
>mean they give customers addresses from the private network address range
>and masquerade, or do they just allocate dynamically a small pool of IP
>numbers?

Just think how many IP's Freeserve would need if it offered every
subscriber a fixed number...

TB               Busby the Cat 1984 - 22.9.1999