ip forwarding

QNX Newsgroups (Archives) qdn.public.qnxrtp.newuser
#1

I have a 16 node QNX 6.1 computer (but for the sakes of this question we
can assume I have 3 nodes) each with two ethernet ports. All the nodes
use one of their ports to connect to an ethernet switch (and therefor
can see each other through tcp/ip and qnet). One node uses the other
ethernet port to connect to the internet.

Currently only this one node can connect to the internet. Can I use ip
forwarding to allow the other two nodes to use the internet connection
on that first node? If so, can someone please give me a sample
configuration. I’ve already used “io-net -d -ptcpip forward” but
I think my problem may be setting up routing. If I need something more
advanced, like IPFilter, can someone walk me through it.

Thanks in advance,
M. Herberg

#2

Matthew Herberg <matthew.herberg@yale.edu> wrote:

I have a 16 node QNX 6.1 computer (but for the sakes of this question we
can assume I have 3 nodes) each with two ethernet ports. All the nodes
use one of their ports to connect to an ethernet switch (and therefor
can see each other through tcp/ip and qnet). One node uses the other
ethernet port to connect to the internet.

Currently only this one node can connect to the internet. Can I use ip
forwarding to allow the other two nodes to use the internet connection
on that first node? If so, can someone please give me a sample
configuration. I’ve already used “io-net -d -ptcpip forward” but
I think my problem may be setting up routing. If I need something more
advanced, like IPFilter, can someone walk me through it.

It depends what kind of “internet connection” your one node (let’s call
it gateway) have.

If you have a public network address, you can put all your nodes into
that network, and use the “-ptcpip forwarding”.

Otherwise, you have to use NAT (Network Address Translation) software,
such as IPFilter.

Another alternative is use QNET. Suppose all you node could see each
other on QNET, (ie: ls /net/gateway is working) you can actually do
this on an internal node:

SOCK=/net/gateway voyager &

This make all tcpip call goes to the tcpip stack on /net/gateway,
the traffic between gateway and internal node is on QNET, you don’t
even need a tcpip stack on internal nodes.

-xtang