[Openvpn-users] RESOLVE: Cannot resolve host address: ... [HOST_NOT

Discussion:

[Openvpn-users] RESOLVE: Cannot resolve host address: ... [HOST_NOT_FOUND]

k***@yahoo.com

2009-03-06 22:01:17 UTC

Josh Cepek

2009-03-07 00:51:28 UTC

Fix your DNS for this client. This has nothing to do with the OpenVPN
client and everything to do with the client's domain name resolver. The
command line tools "host" and "nslookup" (and perhaps "dig" if you have
it installed on a Unix-like OS) will allow you to perform a DNS lookup
on the domain you're attempting to reach. It might be worth
double-checking that the domain name you're trying to lookup really is
reachable on the Internet by trying a query through 4.2.2.1 or another
public DNS server (eg: "nslookup NameOfOurVPNserver.org 4.2.2.1".)

If you can't fix the broken DNS, you could either use the IP since you
know that works or edit the system's hosts file to hardcode the correct
IP for that domain name. Both of these are rather hackish solutions and
should be avoided unless there's no other way around the problem as
future IP changes must be updated by hand.

--
Josh

k***@yahoo.com

2009-03-07 01:49:14 UTC

Permalink

On a Ubuntu desktop system, this is the OpenVPN client conf file:
====================
dev tun001
proto udp
remote NameOfOurVPNserver.org
ifconfig 192.168.21.2 192.168.21.1
secret /home/myself/data/staticVPN.key
log /home/myself/data/logOpenVPN.txt
verb 3
comp-lzo
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
user openvpn
group openvpn
daemon
====================

At boot time, the client system log "/home/myself/data/logOpenVPN.txt" contains:
...
RESOLVE: Cannot resolve host address: NameOfOurVPNserver.org: [HOST_NOT_FOUND] The specified host is unknown.
...
RESOLVE: Cannot resolve host address: NameOfOurVPNserver.org: [HOST_NOT_FOUND] The specified host is unknown.
...

I understand that this is only a OpenVPN client side issue because
the "NameOfOurVPNserver.org" is accessible from everywhere else.

Also, I replaced
remote NameOfOurVPNserver.org
with
remote a.b.c.d
where a.b.c.d is the static WAN ip address of NameOfOurVPNserver.org
then I rebooted this Ubuntu system and this OpenVPN client works immediately.

How can I make this OpenVPN client resolve the host address "NameOfOurVPNserver.org" ?

--- On Fri, 3/6/09, Josh Cepek <***@usa.net> wrote:

Fix your DNS for this client. This has nothing to do with the OpenVPN
client and everything to do with the client's domain name resolver. The
command line tools "host" and "nslookup" (and perhaps "dig" if you have
it installed on a Unix-like OS) will allow you to perform a DNS lookup
on the domain you're attempting to reach. It might be worth
double-checking that the domain name you're trying to lookup really is
reachable on the Internet by trying a query through 4.2.2.1 or another
public DNS server (eg: "nslookup NameOfOurVPNserver.org 4.2.2.1".)

If you can't fix the broken DNS, you could either use the IP since you
know that works or edit the system's hosts file to hardcode the correct
IP for that domain name. Both of these are rather hackish solutions and
should be avoided unless there's no other way around the problem as
future IP changes must be updated by hand.
--
Josh

-------------------------------------------------------------

Ok.

On this Ubuntu OpenVPN client, as root:

host NameOfOurVPNserver.org
NameOfOurVPNserver.org has address a.b.c.d

nslookup NameOfOurVPNserver.org
Server: 192.168.5.1
Address: 192.168.5.1#53

Non-authoritative answer:
Name: NameOfOurVPNserver.org
Address: a.b.c.d

dig NameOfOurVPNserver.org

; <<>> DiG 9.4.1-P1.1 <<>> NameOfOurVPNserver.org
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 36699
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;NameOfOurVPNserver.org. IN A

;; ANSWER SECTION:
NameOfOurVPNserver.org. 3 IN A a.b.c.d

;; Query time: 4 msec
;; SERVER: 192.168.5.1#53(192.168.5.1)
;; WHEN: Fri Mar 6 17:38:41 2009
;; MSG SIZE rcvd: 47

Where a.b.c.d is the static WAN ip address of NameOfOurVPNserver.org

Plus, on this Ubuntu client I put http://NameOfOurVPNserver.org/
in Firefox and the web page loads immediately.

Besides, I am using this Ubuntu client right now to surf the
web, email, chat, etc.

So I don't understand how this could be DNS issue on this client.

Agile Aspect

2009-03-07 02:48:54 UTC

Permalink

Post by k***@yahoo.com
====================
dev tun001
proto udp
remote NameOfOurVPNserver.org
ifconfig 192.168.21.2 192.168.21.1
secret /home/myself/data/staticVPN.key
log /home/myself/data/logOpenVPN.txt
verb 3
comp-lzo
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
user openvpn
group openvpn
daemon
====================
...
RESOLVE: Cannot resolve host address: NameOfOurVPNserver.org: [HOST_NOT_FOUND] The specified host is unknown.
...
RESOLVE: Cannot resolve host address: NameOfOurVPNserver.org: [HOST_NOT_FOUND] The specified host is unknown.
...
I understand that this is only a OpenVPN client side issue because
the "NameOfOurVPNserver.org" is accessible from everywhere else.
Also, I replaced
remote NameOfOurVPNserver.org
with
remote a.b.c.d
where a.b.c.d is the static WAN ip address of NameOfOurVPNserver.org
then I rebooted this Ubuntu system and this OpenVPN client works immediately.
How can I make this OpenVPN client resolve the host address "NameOfOurVPNserver.org" ?
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Add the following to /etc/hosts file on the client

a.b.c.d NameOfOurVPNserver.org

Note, if your DNS server is not accessible from the outside the
LAN then you'll never be able to resolve the address.

As for the DNS server working correctly after you connect, that will
depend on the server's configuration file.

--
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