Client can connect to server but possible routing problems?

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wstewart3
OpenVpn Newbie
Posts: 18
Joined: Wed Mar 04, 2015 1:16 am

Client can connect to server but possible routing problems?

Post by wstewart3 » Thu Mar 12, 2015 1:43 pm

I can successfully connect to my linux VM, I can even type in an IP address to a windows computer on my network. It will begin to connect via RDP, succesfully show some of the screen and then fail. I can also log into my router, but it seems to take a while to find the IP addresses. Can someone see something obvious that I missed?

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client
dev tap
proto udp
remote servername.org 1194
resolv-retry infinite
nobind
persist-key
persist-tun
ns-cert-type server

ca ca.crt
cert client1.crt
key client1.key
tls-auth ta.key 1

cipher BF-CBC
comp-lzo
verb 3

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#################################################
# Sample OpenVPN 2.0 config file for            #
# multi-client server.                          #
#                                               #
# This file is for the server side              #
# of a many-clients <-> one-server              #
# OpenVPN configuration.                        #
#                                               #
# OpenVPN also supports                         #
# single-machine <-> single-machine             #
# configurations (See the Examples page         #
# on the web site for more info).               #
#                                               #
# This config should work on Windows            #
# or Linux/BSD systems.  Remember on            #
# Windows to quote pathnames and use            #
# double backslashes, e.g.:                     #
# "C:\\Program Files\\OpenVPN\\config\\foo.key" #
#                                               #
# Comments are preceded with '#' or ';'         #
#################################################

# Which local IP address should OpenVPN
# listen on? (optional)
;local a.b.c.d

# Which TCP/UDP port should OpenVPN listen on?
# If you want to run multiple OpenVPN instances
# on the same machine, use a different port
# number for each one.  You will need to
# open up this port on your firewall.
port 1194

# TCP or UDP server?
;proto tcp
proto udp

# "dev tun" will create a routed IP tunnel,
# "dev tap" will create an ethernet tunnel.
# Use "dev tap0" if you are ethernet bridging
# and have precreated a tap0 virtual interface
# and bridged it with your ethernet interface.
# If you want to control access policies
# over the VPN, you must create firewall
# rules for the the TUN/TAP interface.
# On non-Windows systems, you can give
# an explicit unit number, such as tun0.
# On Windows, use "dev-node" for this.
# On most systems, the VPN will not function
# unless you partially or fully disable
# the firewall for the TUN/TAP interface.
dev tap0
;dev tun

# Windows needs the TAP-Win32 adapter name
# from the Network Connections panel if you
# have more than one.  On XP SP2 or higher,
# you may need to selectively disable the
# Windows firewall for the TAP adapter.
# Non-Windows systems usually don't need this.
;dev-node MyTap

# SSL/TLS root certificate (ca), certificate
# (cert), and private key (key).  Each client
# and the server must have their own cert and
# key file.  The server and all clients will
# use the same ca file.
#
# See the "easy-rsa" directory for a series
# of scripts for generating RSA certificates
# and private keys.  Remember to use
# a unique Common Name for the server
# and each of the client certificates.
#
# Any X509 key management system can be used.
# OpenVPN can also use a PKCS #12 formatted key file
# (see "pkcs12" directive in man page).
ca ca.crt
cert server.crt
key server.key  # This file should be kept secret

# Diffie hellman parameters.
# Generate your own with:
#   openssl dhparam -out dh1024.pem 1024
# Substitute 2048 for 1024 if you are using
# 2048 bit keys. 
dh dh2048.pem

# Configure server mode and supply a VPN subnet
# for OpenVPN to draw client addresses from.
# The server will take 10.8.0.1 for itself,
# the rest will be made available to clients.
# Each client will be able to reach the server
# on 10.8.0.1. Comment this line out if you are
# ethernet bridging. See the man page for more info.
;server 10.8.0.0 255.255.255.0

# Maintain a record of client <-> virtual IP address
# associations in this file.  If OpenVPN goes down or
# is restarted, reconnecting clients can be assigned
# the same virtual IP address from the pool that was
# previously assigned.
ifconfig-pool-persist ipp.txt

# Configure server mode for ethernet bridging.
# You must first use your OS's bridging capability
# to bridge the TAP interface with the ethernet
# NIC interface.  Then you must manually set the
# IP/netmask on the bridge interface, here we
# assume 10.8.0.4/255.255.255.0.  Finally we
# must set aside an IP range in this subnet
# (start=10.8.0.50 end=10.8.0.100) to allocate
# to connecting clients.  Leave this line commented
# out unless you are ethernet bridging.
;server-bridge 10.8.0.4 255.255.255.0 10.8.0.50 10.8.0.100
server-bridge '192.168.1.1' '255.255.255.0' '192.168.1.115' '192.168.1.250'


# Configure server mode for ethernet bridging
# using a DHCP-proxy, where clients talk
# to the OpenVPN server-side DHCP server
# to receive their IP address allocation
# and DNS server addresses.  You must first use
# your OS's bridging capability to bridge the TAP
# interface with the ethernet NIC interface.
# Note: this mode only works on clients (such as
# Windows), where the client-side TAP adapter is
# bound to a DHCP client.
;server-bridge

# Push routes to the client to allow it
# to reach other private subnets behind
# the server.  Remember that these
# private subnets will also need
# to know to route the OpenVPN client
# address pool (10.8.0.0/255.255.255.0)
# back to the OpenVPN server.
;push "route 192.168.10.0 255.255.255.0"
;push "route 192.168.20.0 255.255.255.0"
push "route 192.168.1.1 255.255.255.0"

# To assign specific IP addresses to specific
# clients or if a connecting client has a private
# subnet behind it that should also have VPN access,
# use the subdirectory "ccd" for client-specific
# configuration files (see man page for more info).

# EXAMPLE: Suppose the client
# having the certificate common name "Thelonious"
# also has a small subnet behind his connecting
# machine, such as 192.168.40.128/255.255.255.248.
# First, uncomment out these lines:
;client-config-dir ccd
;route 192.168.40.128 255.255.255.248
# Then create a file ccd/Thelonious with this line:
#   iroute 192.168.40.128 255.255.255.248
# This will allow Thelonious' private subnet to
# access the VPN.  This example will only work
# if you are routing, not bridging, i.e. you are
# using "dev tun" and "server" directives.

# EXAMPLE: Suppose you want to give
# Thelonious a fixed VPN IP address of 10.9.0.1.
# First uncomment out these lines:
;client-config-dir ccd
;route 10.9.0.0 255.255.255.252
# Then add this line to ccd/Thelonious:
#   ifconfig-push 10.9.0.1 10.9.0.2

# Suppose that you want to enable different
# firewall access policies for different groups
# of clients.  There are two methods:
# (1) Run multiple OpenVPN daemons, one for each
#     group, and firewall the TUN/TAP interface
#     for each group/daemon appropriately.
# (2) (Advanced) Create a script to dynamically
#     modify the firewall in response to access
#     from different clients.  See man
#     page for more info on learn-address script.
;learn-address ./script

# If enabled, this directive will configure
# all clients to redirect their default
# network gateway through the VPN, causing
# all IP traffic such as web browsing and
# and DNS lookups to go through the VPN
# (The OpenVPN server machine may need to NAT
# or bridge the TUN/TAP interface to the internet
# in order for this to work properly).
push "redirect-gateway def1 bypass-dhcp"

# Certain Windows-specific network settings
# can be pushed to clients, such as DNS
# or WINS server addresses.  CAVEAT:
# http://openvpn.net/faq.html#dhcpcaveats
# The addresses below refer to the public
# DNS servers provided by opendns.com.
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.4.4"
push "dhcp-option DNS 192.168.1.1"

# Uncomment this directive to allow different
# clients to be able to "see" each other.
# By default, clients will only see the server.
# To force clients to only see the server, you
# will also need to appropriately firewall the
# server's TUN/TAP interface.
;client-to-client

# Uncomment this directive if multiple clients
# might connect with the same certificate/key
# files or common names.  This is recommended
# only for testing purposes.  For production use,
# each client should have its own certificate/key
# pair.
#
# IF YOU HAVE NOT GENERATED INDIVIDUAL
# CERTIFICATE/KEY PAIRS FOR EACH CLIENT,
# EACH HAVING ITS OWN UNIQUE "COMMON NAME",
# UNCOMMENT THIS LINE OUT.
;duplicate-cn

# The keepalive directive causes ping-like
# messages to be sent back and forth over
# the link so that each side knows when
# the other side has gone down.
# Ping every 10 seconds, assume that remote
# peer is down if no ping received during
# a 120 second time period.
keepalive 10 120

# For extra security beyond that provided
# by SSL/TLS, create an "HMAC firewall"
# to help block DoS attacks and UDP port flooding.
#
# Generate with:
#   openvpn --genkey --secret ta.key
#
# The server and each client must have
# a copy of this key.
# The second parameter should be '0'
# on the server and '1' on the clients.
tls-auth ta.key 0 # This file is secret

# Select a cryptographic cipher.
# This config item must be copied to
# the client config file as well.
;cipher BF-CBC        # Blowfish (default)
;cipher AES-128-CBC   # AES
;cipher DES-EDE3-CBC  # Triple-DES

# Enable compression on the VPN link.
# If you enable it here, you must also
# enable it in the client config file.
comp-lzo

# The maximum number of concurrently connected
# clients we want to allow.
;max-clients 100

# It's a good idea to reduce the OpenVPN
# daemon's privileges after initialization.
#
# You can uncomment this out on
# non-Windows systems.
user nobody
group nogroup

# The persist options will try to avoid
# accessing certain resources on restart
# that may no longer be accessible because
# of the privilege downgrade.
persist-key
persist-tun

# Output a short status file showing
# current connections, truncated
# and rewritten every minute.
status openvpn-status.log

# By default, log messages will go to the syslog (or
# on Windows, if running as a service, they will go to
# the "\Program Files\OpenVPN\log" directory).
# Use log or log-append to override this default.
# "log" will truncate the log file on OpenVPN startup,
# while "log-append" will append to it.  Use one
# or the other (but not both).
;log         openvpn.log
;log-append  openvpn.log

# Set the appropriate level of log
# file verbosity.
#
# 0 is silent, except for fatal errors
# 4 is reasonable for general usage
# 5 and 6 can help to debug connection problems
# 9 is extremely verbose
verb 3

# Silence repeating messages.  At most 20
# sequential messages of the same message
# category will be output to the log.
;mute 20

up "/etc/openvpn/up.sh br0"
down "/etc/openvpn/down.sh br0"
script-security 3
And lastly, the client log shows some interesting behavior:

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Thu Mar 12 09:33:30 2015 C:\Windows\system32\route.exe ADD 192.168.1.1 MASK 255.255.255.0 192.168.1.1
Thu Mar 12 09:33:30 2015 Warning: address 192.168.1.1 is not a network address in relation to netmask 255.255.255.0
But otherwise, it seems I almost have it working! Please let me know if you have any suggestions!

wstewart3
OpenVpn Newbie
Posts: 18
Joined: Wed Mar 04, 2015 1:16 am

Re: Client can connect to server but possible routing proble

Post by wstewart3 » Thu Mar 12, 2015 6:45 pm

Actually everything seems to be working EXCEPT RDP. I can authenticate, connect, and get the first few frames, and then it dies. But I can pull up the router main web page, SSH into it, access my FTP server using the local IP. Everything seems to be working phenomenally except RDP (Which is the main reason for this!)

I found a few post with little to no resolutions. any ideas?

User avatar
Traffic
OpenVPN Protagonist
Posts: 4066
Joined: Sat Aug 09, 2014 11:24 am

Re: Client can connect to server but possible routing proble

Post by Traffic » Thu Mar 12, 2015 8:47 pm

wstewart3 wrote:Actually everything seems to be working EXCEPT RDP
M$ RDP is a Tsunami of unsupport[able]ed closed source code ...

http://windows.microsoft.com/en-GB/wind ... connection

On your OpenVPN, did you follow the HOWTO for:
HOWTO: Routing all client traffic (including web-traffic) through the VPN

wstewart3
OpenVpn Newbie
Posts: 18
Joined: Wed Mar 04, 2015 1:16 am

Re: Client can connect to server but possible routing proble

Post by wstewart3 » Fri Mar 13, 2015 2:48 pm

Thanks for the reply!

That is really concerning! I just changed my config from a bridge to a tunnel to see if I would get anything different but it has the exact some result. I read through that link you sent me and I have added all those iptables routes. I can connect just fine. my FTP sever will even connect and download to and from the server.

So I know it is handshaking correctly, and even sending and receiving data correct as I get about 2 seconds of normal activity. I will continue looking though! I Would love to have this working.

User avatar
Traffic
OpenVPN Protagonist
Posts: 4066
Joined: Sat Aug 09, 2014 11:24 am

Re: Client can connect to server but possible routing proble

Post by Traffic » Fri Mar 13, 2015 3:05 pm

wstewart3 wrote:

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server-bridge '192.168.1.1' '255.255.255.0' '192.168.1.115' '192.168.1.250'
push "route 192.168.1.1 255.255.255.0"
You do not require the text delimiters [ 'x.x.x.x' ] in your server-bridge directive. ie: the apostrophes ' '

Change the push to:

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push "route 192.168.1.1"
wstewart3 wrote:I just changed my config from a bridge to a tunnel to see if I would get anything different but it has the exact some result.
jeez .. did you also enable the iptables NAT rule correctly on your server ?

BTW ..
  • NOTE: your local LAN uses the extremely common subnet address 192.168.0.x or 192.168.1.x. Be aware that this might create routing conflicts if you connect to the VPN server from public locations such as internet cafes that use the same subnet.
:roll:

wstewart3
OpenVpn Newbie
Posts: 18
Joined: Wed Mar 04, 2015 1:16 am

Re: Client can connect to server but possible routing proble

Post by wstewart3 » Fri Mar 13, 2015 3:17 pm

Thanks for the quick response. I will try the changes you suggested.

And of course I added the nat rules, otherwise nothing would work.

But I can successfully connect to my network via my android phone, and RDP works fine using the android RDP app. I will have to look into it. but I dont think it is an openvpn issue now...at least not a direct one.

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