[SOLVED] The problem with redirecting IP address

orrik · 07-19-2016, 06:49 AM

Hello

I have two public IP addresses. For just the one of them (111.222.333.444) I registered the domain http://somedomain.org. In the settings of servers dns provider I pointed my public IP address (111.222.333.444).
I started the DNS and Web on one of the computers on the local network with the address 192.168.0.195. The DNS server running the Web as well. DNS translates names into IP addresses and vice versa.

Code:

# nslookup google.com
Server:         127.0.0.1
Address:        127.0.0.1#53

Non-authoritative answer:
Name:   google.com
Address: 216.58.209.174

Code:

# nslookup 216.58.209.174
Server:         127.0.0.1
Address:        127.0.0.1#53

Non-authoritative answer:
174.209.58.216.in-addr.arpa     name = bud02s21-in-f14.1e100.net.
174.209.58.216.in-addr.arpa     name = bud02s21-in-f174.1e100.net.

Authoritative answers can be found from:
209.58.216.in-addr.arpa nameserver = ns3.google.com.
209.58.216.in-addr.arpa nameserver = ns2.google.com.
209.58.216.in-addr.arpa nameserver = ns1.google.com.
209.58.216.in-addr.arpa nameserver = ns4.google.com.
ns2.google.com  internet address = 216.239.34.10
ns4.google.com  internet address = 216.239.38.10
ns1.google.com  internet address = 216.239.32.10
ns3.google.com  internet address = 216.239.36.10

Code:

# ping google.com
PING google.com (216.58.209.174) 56(84) bytes of data.
64 bytes from bud02s21-in-f174.1e100.net (216.58.209.174): icmp_seq=1 ttl=58 time=27.3 ms
64 bytes from bud02s21-in-f174.1e100.net (216.58.209.174): icmp_seq=2 ttl=58 time=27.2 ms
^C
--- google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1341ms
rtt min/avg/max/mdev = 27.254/27.316/27.378/0.062 ms

Code:

# host google.com
google.com has address 216.58.209.174
google.com has IPv6 address 2a00:1450:400d:802::200e
google.com mail is handled by 20 alt1.aspmx.l.google.com.
google.com mail is handled by 40 alt3.aspmx.l.google.com.
google.com mail is handled by 10 aspmx.l.google.com.
google.com mail is handled by 50 alt4.aspmx.l.google.com.
google.com mail is handled by 30 alt2.aspmx.l.google.com.

In my router (Linux) in the firewall did redirecting 111.222.333.444 IP address 192.168.0.195.

Code:

G_NET_IP1=111.222.333.444
L_S1_IP=192.168.0.195
iptables -t nat -A PREROUTING -d $G_NET_IP1 -j DNAT --to-destination $L_S1_IP
iptables -t nat -A POSTROUTING -s $L_S1_IP  -j SNAT --to-source $G_NET_IP1

And here begins my problem ... internet on the web is seen but only after entering the IP address or http://111.222.333.444. When I type the address http://somedomain.org I have a message that the page does not exist.

It seems to me that I have kicked off a redirect in my firewall but I can not deal with it. Do any of you could point out where I made a mistake?

Regards
orrik

gda · 07-19-2016, 09:03 AM

It's strange... To me it sounds like only the DNS resolution is not working...
Did you check if your domain is actually resolved by your DNS provider?

Moreover as far as I understood you have set-up an additional local DNS which is different from the one resolving your domain. It is not clear to me why you need it as you are making nat using iptables.

orrik · 07-20-2016, 12:45 AM

Quote:

Originally Posted by gda

It's strange... To me it sounds like only the DNS resolution is not working...
Did you check if your domain is actually resolved by your DNS provider?

I think so. I've never had a problem with it. But I check it and.

Quote:

Moreover as far as I understood you have set-up an additional local DNS which is different from the one resolving your domain.

Yes. At the moment it looks like it has two functions - server and router.
At the ip address 111,222,333,444 I wanna get Wine to launch second server. When ready to replace the current server on the router and firewall.

Quote:

It is not clear to me why you need it as you are making nat using iptables.

The reason that such a solution seems to me to be the best for my intentions.
You are suggesting a different solution? What? We are happy with him I will read.

Regards

JJJCR · 07-20-2016, 01:29 AM

Linux is also acting as a router? or you have a physical router or firewall between your ISP?

orrik · 07-20-2016, 02:00 AM

Quote:

Originally Posted by JJJCR

Linux is also acting as a router? or you have a physical router or firewall between your ISP?

Everything is on linux. No hardware solutions

gda · 07-20-2016, 03:27 AM

As far as I understood from the first post in this thread your final goal is to run a web server on the private IP 192.168.0.195 and make it answering to http requests made using the name http://somedomain.org which is resolved in the public IP 111.222.333.444.

To accomplish that you should need:

1) A DNS server performing the forward and reverse resolution for the domain http://somedomain.org to IP 111.222.333.444 - this job is done by your (external) DNS provider
2) A router forwarding all the traffic from 111.222.333.444 to 192.168.0.195 (and the way back) - and this job is done by your local Linux router using the two iptable rules you reported above (by the way I would change a bit both these rules specifying also the port 80 or other ports you would like to use for http connection)

I think a second local DNS is not needed.

Moreover as http://111.222.333.444 redirects you to the right place, I suppose your firewall/router configurations are correct otherwise you wouldn't be able to contact your web server.

Just check if the forward and reverse resolution of the domain http//somedomain.org is working as expected. You could also check using for example traceroute or tcpdump where the communication stops to work.

JJJCR · 07-20-2016, 03:57 AM

So basically, you are not able to ping your domain name right? The http://somedomain.org.

Did you give some time to propagate the DNS?

I think you might need to contact the hosting provider why it's not resolving the domain name.

Have you tried the whois tool on Google to check your domain name.

Quote:

http://whois.domaintools.com/<domain_name.com>

orrik · 07-20-2016, 07:09 AM

Hello

Thank you all for your suggestions. It is working now! GDA you were right. The case was messed up DNS provider. After the intervention it's working.
THX gda!

Regards