Dynamic IP assigned to remote computer

QNX Newsgroups (Archives) qdn.public.qnx4.devtools
1

Hello,

At present we are working on a project that requires data transfer
between two QNX computers using GPRS. Both the computers dial the number of
local service provider and establish a ppp connectivity. The service
provider assigns IP addresses dynamically to each computer. For
transferring data to remote computer we need to know the IP address (which
is dynamically assigned) of remote computer.

How to find IP of the remote computer ? Are there any TCPIP functions
with the help of which we can find out IP of remote computer?

Thanks,
Krupa

2

“Krupa” <seto@vsnl.com> wrote in message news:b37suh$95r$1@inn.qnx.com…

Hello,

At present we are working on a project that requires data transfer
between two QNX computers using GPRS. Both the computers dial the number
of
local service provider and establish a ppp connectivity. The service
provider assigns IP addresses dynamically to each computer. For
transferring data to remote computer we need to know the IP address (which
is dynamically assigned) of remote computer.

How to find IP of the remote computer ? Are there any TCPIP functions
with the help of which we can find out IP of remote computer?

Yes it’s called DNS. You service provider must update their DNS entries
upon connection so that you can reach the computer via its name (and not
vial its IP address).

Aside from DNS other solution are possible but pretty funky- have a third
computer act as name server or use broadcast (if in same segment)

Thanks,
Krupa

3

Mario,

If I understand the situation correctly here, two computers are each getting
their IP addresses dynamically assigned (probably by DHCP), and need to find
each other. Is it always the case that ISPs enter DNS names for such IPs?
Even if so, must they always assign the same name to a given dialup client
each time? That seems pretty far-fetched.

So it seems to me the best bet would be to have each of those computers (or
at least the one that is not the one initiating the data transfer) tell some
trusted third party its IP, so that the other computer can then contact that
third party to find it out. The ISP might very well be the ideal third
party, of course, since most ISPs are happy to provide a little disk space.

dB

“Mario Charest” postmaster@127.0.0.1 wrote in message
news:b382bs$e78$1@inn.qnx.com…

“Krupa” <> seto@vsnl.com> > wrote in message news:b37suh$95r$> 1@inn.qnx.com> …
Hello,

At present we are working on a project that requires data transfer
between two QNX computers using GPRS. Both the computers dial the number
of
local service provider and establish a ppp connectivity. The service
provider assigns IP addresses dynamically to each computer. For
transferring data to remote computer we need to know the IP address
(which
is dynamically assigned) of remote computer.

How to find IP of the remote computer ? Are there any TCPIP
functions
with the help of which we can find out IP of remote computer?

Yes it’s called DNS. You service provider must update their DNS entries
upon connection so that you can reach the computer via its name (and not
vial its IP address).

Aside from DNS other solution are possible but pretty funky- have a third
computer act as name server or use broadcast (if in same segment)


Thanks,
Krupa
\

4

“David Bacon” <dbacon@qnx.com> wrote in message
news:b391d9$rdt$1@nntp.qnx.com…

Mario,

If I understand the situation correctly here, two computers are each
getting
their IP addresses dynamically assigned (probably by DHCP), and need to
find
each other. Is it always the case that ISPs enter DNS names for such IPs?
Even if so, must they always assign the same name to a given dialup
client
each time? That seems pretty far-fetched.

Yeah depends on the ISP, some will give a name that matches the cable modem.
You are right, unless your ISP is willing to provide you these “special”
services that doens’t look like a viable solution

So it seems to me the best bet would be to have each of those computers
(or
at least the one that is not the one initiating the data transfer) tell
some
trusted third party its IP, so that the other computer can then contact
that
third party to find it out. The ISP might very well be the ideal third
party, of course, since most ISPs are happy to provide a little disk
space.

There are third party that can provide free name services (dns2go,
freeftp, ) from memory dns2go provides source so you can port it the OS of
your choice ( I pretty sure I ported the dns2go stuff a few years ago ).


dB

“Mario Charest” postmaster@127.0.0.1 wrote in message
news:b382bs$e78$> 1@inn.qnx.com> …

“Krupa” <> seto@vsnl.com> > wrote in message
news:b37suh$95r$> 1@inn.qnx.com> …
Hello,

At present we are working on a project that requires data transfer
between two QNX computers using GPRS. Both the computers dial the
number
of
local service provider and establish a ppp connectivity. The service
provider assigns IP addresses dynamically to each computer. For
transferring data to remote computer we need to know the IP address
(which
is dynamically assigned) of remote computer.

How to find IP of the remote computer ? Are there any TCPIP
functions
with the help of which we can find out IP of remote computer?

Yes it’s called DNS. You service provider must update their DNS entries
upon connection so that you can reach the computer via its name (and not
vial its IP address).

Aside from DNS other solution are possible but pretty funky- have a
third
computer act as name server or use broadcast (if in same segment)


Thanks,
Krupa

\