Re: routing

[Sthu Deus <sthu.deus@gmail.com>]

Thank You for Your time and answer, Jesús:

> Sorry for the long delay.

Please do not worry - I myself am often very busy. :)
That's why I like mail - reply when at ease.

> What's the machine that holds the 10.10.10.10 IP address? My bet is
> that it's some kind of router owned by your ISP; I don't know if
> located on your premises or those of your ISP.  Am I right?

Yes, absolutely.

> > > 2) Can you ping 10.10.10.10 from host2?  
> >
> > Yes.  
> 
> If I don't recall wrongly, host2 is your routing one, sitting in
> between your internal network and your Internet connection.  Is this
> right?

Well. That's what we have here - just reminding so that everything was
fresh:

host1 <-> eth <-> host2 <-> ppp <-> Internet.

host1 has eth0 w/ 192.168.0.2
host2 has eth0 w/ 192.168.0.125 and ppp0 w/ 10.10.10.10
Internet 20.20.20.20

> > > 3) Can you ping 152.46.7.81 from host2?  
> >
> > No.  
> 
> That's a known server on Internet; the one hosting www.tldp.org and
> it does return pings.  That means that your routing host is unable to
> reach Internet. Is that true?  Are you sure your only defined
> interfaces on host2 are lo, eth0 and eth1 and that the only firewall
> rules applied were the ones I provided?

The interfaces are: lo ppp and eth. Yes, I did as You said.

Jesús, we latter w/ another person some time ago, here, has discovered,
that all I needed to have for the host1 access to Internet was the
necessity for host2 to route the packets from Internet back to host1 -
that is masquerading. - Therefore it works. - I thought You have seen
the message. I the reason why we then continued our talk w/ You was that
You said that (or I have understood so) it is possible to make routung
other way than through iptables - as I understand, through routing
tables - the ones we see w/ ip command - is it correct/possible? - Or we
just waste one another's time? :) 

> > > 4) Can you ping 192.168.0.3 from host2?  
> >
> > Not ping but connect by ssh.  
> 
> Is there any firewall on host1? Are you sure your only defined

Well. there is another firewall.

> interfaces on host2 are lo eth0 and eth1 and that the only firewall
> rules applied were the ones I provided?  No ping but ssh ability

Yes.

> smells strongly like a firewall problem, not one about routing.

Yea - I just ment here that there is traffic between the hosts - just
wanted to be honest w/ You. :) - It is true - the pings are just
blocked. But for the Internet connection it is open - related is in
INPUT chain.

> > > 5) Can you ping 192.168.0.125 from host1?  
> >
> > Yes.  
> 
> Definetly there's some firewall-related problem hidden somewhere here.

Yes - masquerading. :)

> > > 6) Can you ping 20.20.20.20 from host1?  
> >
> > No. - How it can if now masquerading on host2?  
> 
> Do you really mean "now masquerading" or "no masquerading"?  If the

"no masquerading" of course - or it becomes illogical.

> > > 7) Can you ping 152.46.7.81 from host1?  
> >
> > No.  
> 
> This was expected as this time.
> 
> If you are still working out this problem, can you please start a
> thread anew providing topology/IP address space again?  I already
> deleted these posts from my local spool and I'm having problems
> finding this thread on Debian's list servers.

Well. I have said already about solving of the problem And interest if
it is possible to go another way - through ip table routing - that is
not clear to me why it exists while there is iptables, for example -
is it not interchangeable?

As for the list search of the message:
http://lists.debian.org/debian-user/2010/10/msg01704.html

Thank, Jesús, for the attention You have paid to my problem - I do
appreciate it much.