Cannot ping Linux machines eachother after OpenVPN

mmc18

I have two linux servers whose Ips are 47.16896.31 and 47.168.96.33
I have executed the following command in each linux machine respectively after than realise that these nodes cannot ping each other,

at HOST1: 47.168.96.31
#openvpn --ifconfig 47.168.96.31 47.168.96.33 --dev tun
#ping 47.168.96.33 ===>> doesnot reply

at Linux machine HOST2: 47.168.96.33
#openvpn --ifconfig 47.168.96.33 47.168.96.31 --dev tun
#ping 47.168.96.31 ===>> doesnot reply

Both linux machine does not have any name registered DNS so I cannot give --remote parameter properly.

Could you please take a look at where I am doing wrong?

maikcat

if they use 47.168.96.31 and 47.168.96.33 for their lan interface
you MUST use other (private maybe) ips for the virtual tun interface.

Michael.

mmc18

You are right,
IP of real or IP of Virtual has to be different. In other words
After modification of the command parameter as below, it works

dev tap22
float
remote 47.168.96.31:8081
ifconfig 10.3.0.3 255.255.255.0

dev tap22
float
remote 47.168.96.33:8081
ifconfig 10.3.0.1 255.255.255.0

besides that I have two concerns
first one:
I am listening on 8081 port since my Apache Http Server run on that port.
When I send URL 10.3.0.1:8081 It works, but it is so slow. What is reason?

Second:
When I run OPenVPN at OSI layer3, normally it should not listen any specific port (1194, 8081). How I can configure OpenVpn to get it run at Layer3? If so, how OpenVPN canhandle VPN by using SSL (Layer4) to run on at Layer3.
There is an conceptional difference?
Could you please clarify it?
The main purpose is to make a secure connection between two end-points at Layer3 without dealing with port.

Thanks in advance.

maikcat

besides that I have two concerns
first one:
I am listening on 8081 port since my Apache Http Server run on that port.
When I send URL 10.3.0.1:8081 It works, but it is so slow. What is reason?

maybe MTU issue...
apache logs shows something interesting?

Second:
When I run OPenVPN at OSI layer3, normally it should not listen any specific port (1194, 8081). How I can configure OpenVpn to get it run at Layer3? If so, how OpenVPN canhandle VPN by using SSL (Layer4) to run on at Layer3.
There is an conceptional difference?
Could you please clarify it?
The main purpose is to make a secure connection between two end-points at Layer3 without dealing with port.

openvpn uses tcp or udp to communicate,
also it encrypts & encapsulates packets before it transmits them.

dont forget that PPtP works like that(well...partially..)
IPSec in the other hand uses ESP (layer3).
if developers add support for other non layer 4 protocols (icmp) then yes you will
make a secure connection without dealing with ports and stuff..

OpenVPN implements OSI layer 2 or 3 secure network extension using the SSL/TLS protocol, supports flexible client authentication methods based on certificates, smart cards, and/or 2-factor authentication, and allows user or group-specific access control policies using firewall rules applied to the VPN virtual interface

i believe the above says it all..

also download this:
http://openvpn.net/papers/BLUG-talk/BLUG-talk.ppt

Michael.