Can connect to VPN but can't escape the LAN

sambeniii

Hey guys, I've been searching on the web for hours now, feel like I've tried everything and I just can't get it! I'm using CentOS on the server and Windows7 on the client. I can successfully get the connection up, but once I'm on I can't access the internet in any capacity.

This seems like a relatively common issue but the solutions that seem to work for everyone don't work for me.

This isn't a DNS as I cannot ping even known public IP addresses from the VPN client, only addresses in the 10.8.0.0 network. I'm positive the issue is based in the server not properly routing the packets from the client out, but I'm not sure how to remedy the situation. I've got "iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE" added to my iptables and I've also tried doing this as SNAT instead, got same results. Also of note is that there is no default gateway in the ipconfig on the client machine. I've read that this is a cosmetic thing and as such I have partially dismissed this as an issue.

Server Config

# 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 50056

# 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 tap
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 dh2048.pem 2048
dh dh2048.pem

# Network topology
# Should be subnet (addressing via IP)
# unless Windows clients v2.0.9 and lower have to
# be supported (then net30, i.e. a /30 per client)
# Defaults to net30 (not recommended)
;topology subnet

# 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

# 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"

# 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"

# 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"

# 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 nobody# 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

Client Config

client
dev tun
proto udp
remote *removed* 50056
resolv-retry infinite
nobind
persist-key
persist-tun
comp-lzo
verb 3
ca C:\\YourKeys\\ca.crt
cert C:\\YourKeys\\client.crt
key C:\\YourKeys\\client.key

I greatly appreciate any help that can be given, and will submit logs or other config files if the need be.

Traffic

sambeniii wroteve got "iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE" added to my iptables

I presume your NIC is eth0 ? (ifconfig)

sambeniii wrote Also of note is that there is no default gateway in the ipconfig on the client machine

Default gateway is required (route print)

Please post your server and client logs. (you can hide your public ip address)

sambeniii

Yes, eth0 is my outward facing interface.
The following is my clients IPv4 Route Table, I see that my default route ends in my actual machines gateway, which I believe is supposed to be like that right? Also of note is that there is a 10.8.0.5 address listed as the gateway for a few destinations, including another default route. This 10.8.0.5 gateway doesn't go anywhere as there is nothing listening on that address I believe.

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1      192.168.1.6     10
          0.0.0.0        128.0.0.0         10.8.0.5         10.8.0.6     20
         10.8.0.0    255.255.255.0         10.8.0.5         10.8.0.6     20
         10.8.0.4  255.255.255.252         On-link          10.8.0.6    276
         10.8.0.6  255.255.255.255         On-link          10.8.0.6    276
         10.8.0.7  255.255.255.255         On-link          10.8.0.6    276
      [Servers public IP]  255.255.255.255      192.168.1.1      192.168.1.6     10
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
        128.0.0.0        128.0.0.0         10.8.0.5         10.8.0.6     20
      192.168.1.0    255.255.255.0         On-link       192.168.1.6    266
      192.168.1.6  255.255.255.255         On-link       192.168.1.6    266
    192.168.1.255  255.255.255.255         On-link       192.168.1.6    266
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link       192.168.1.6    266
        224.0.0.0        240.0.0.0         On-link          10.8.0.6    276
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link       192.168.1.6    266
  255.255.255.255  255.255.255.255         On-link          10.8.0.6    276
===========================================================================
Persistent Routes:
  None

openvpn-status.log from server

OpenVPN CLIENT LIST
Updated,Sat Jan 16 18:40:58 2016
Common Name,Real Address,Bytes Received,Bytes Sent,Connected Since
ROUTING TABLE
Virtual Address,Common Name,Real Address,Last Ref
GLOBAL STATS
Max bcast/mcast queue length,0
END

Client connection log in verb3

Sat Jan 16 13:42:33 2016 OpenVPN 2.3.10 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [PKCS11] [IPv6] built on Jan  4 2016
Sat Jan 16 13:42:33 2016 Windows version 6.1 (Windows 7)
Sat Jan 16 13:42:33 2016 library versions: OpenSSL 1.0.1q 3 Dec 2015, LZO 2.09
Enter Management Password:
Sat Jan 16 13:42:33 2016 MANAGEMENT: TCP Socket listening on [AF_INET]127.0.0.1:25340
Sat Jan 16 13:42:33 2016 Need hold release from management interface, waiting...
Sat Jan 16 13:42:34 2016 MANAGEMENT: Client connected from [AF_INET]127.0.0.1:25340
Sat Jan 16 13:42:34 2016 MANAGEMENT: CMD 'state on'
Sat Jan 16 13:42:34 2016 MANAGEMENT: CMD 'log all on'
Sat Jan 16 13:42:34 2016 MANAGEMENT: CMD 'hold off'
Sat Jan 16 13:42:34 2016 MANAGEMENT: CMD 'hold release'
Sat Jan 16 13:42:34 2016 WARNING: No server certificate verification method has been enabled.  See http://openvpn.net/howto.html#mitm for more info.
Sat Jan 16 13:42:34 2016 Socket Buffers: R=[8192->8192] S=[8192->8192]
Sat Jan 16 13:42:34 2016 UDPv4 link local: [undef]
Sat Jan 16 13:42:34 2016 UDPv4 link remote: [AF_INET][Server's public IP]:50056
Sat Jan 16 13:42:34 2016 MANAGEMENT: >STATE:1452969754,WAIT,,,
Sat Jan 16 13:42:34 2016 MANAGEMENT: >STATE:1452969754,AUTH,,,
Sat Jan 16 13:42:34 2016 TLS: Initial packet from [AF_INET][Server's public IP]:50056, sid=eeb2deb8 7210640e
Sat Jan 16 13:42:34 2016 VERIFY OK: depth=1, C=US, ST=MD, L=Baltimore, O=NotWizards, OU=NotWizards.space, CN=notwizards.space, name=server, emailAddress=admin@notwizards.space
Sat Jan 16 13:42:34 2016 VERIFY OK: depth=0, C=US, ST=MD, L=Baltimore, O=NotWizards, OU=NotWizards.space, CN=notwizards.space, name=server, emailAddress=admin@notwizards.space
Sat Jan 16 13:42:34 2016 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Sat Jan 16 13:42:34 2016 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Sat Jan 16 13:42:34 2016 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Sat Jan 16 13:42:34 2016 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Sat Jan 16 13:42:34 2016 Control Channel: TLSv1.2, cipher TLSv1/SSLv3 DHE-RSA-AES256-GCM-SHA384, 2048 bit RSA
Sat Jan 16 13:42:34 2016 [notwizards.space] Peer Connection Initiated with [AF_INET]45.63.70.25:50056
Sat Jan 16 13:42:35 2016 MANAGEMENT: >STATE:1452969755,GET_CONFIG,,,
Sat Jan 16 13:42:36 2016 SENT CONTROL [notwizards.space]: 'PUSH_REQUEST' (status=1)
Sat Jan 16 13:42:36 2016 PUSH: Received control message: 'PUSH_REPLY,redirect-gateway def1,dhcp-option DNS 8.8.8.8,dhcp-option DNS 8.8.4.4,route 10.8.0.0 255.255.255.0,topology net30,ping 10,ping-restart 120,ifconfig 10.8.0.6 10.8.0.5'
Sat Jan 16 13:42:36 2016 OPTIONS IMPORT: timers and/or timeouts modified
Sat Jan 16 13:42:36 2016 OPTIONS IMPORT: --ifconfig/up options modified
Sat Jan 16 13:42:36 2016 OPTIONS IMPORT: route options modified
Sat Jan 16 13:42:36 2016 OPTIONS IMPORT: --ip-win32 and/or --dhcp-option options modified
Sat Jan 16 13:42:36 2016 ROUTE_GATEWAY 192.168.1.1/255.255.255.0 I=10 HWADDR=00:26:18:35:fd:aa
Sat Jan 16 13:42:36 2016 do_ifconfig, tt->ipv6=0, tt->did_ifconfig_ipv6_setup=0
Sat Jan 16 13:42:36 2016 MANAGEMENT: >STATE:1452969756,ASSIGN_IP,,10.8.0.6,
Sat Jan 16 13:42:36 2016 open_tun, tt->ipv6=0
Sat Jan 16 13:42:36 2016 TAP-WIN32 device [Local Area Connection 2] opened: \\.\Global\{F6744CD0-6840-4ACB-AF2F-C5B555ABC879}.tap
Sat Jan 16 13:42:36 2016 TAP-Windows Driver Version 9.21 
Sat Jan 16 13:42:36 2016 Notified TAP-Windows driver to set a DHCP IP/netmask of 10.8.0.6/255.255.255.252 on interface {F6744CD0-6840-4ACB-AF2F-C5B555ABC879} [DHCP-serv: 10.8.0.5, lease-time: 31536000]
Sat Jan 16 13:42:36 2016 Successful ARP Flush on interface [23] {F6744CD0-6840-4ACB-AF2F-C5B555ABC879}
Sat Jan 16 13:42:41 2016 TEST ROUTES: 2/2 succeeded len=1 ret=1 a=0 u/d=up
Sat Jan 16 13:42:41 2016 C:\Windows\system32\route.exe ADD 45.63.70.25 MASK 255.255.255.255 192.168.1.1
Sat Jan 16 13:42:41 2016 ROUTE: CreateIpForwardEntry succeeded with dwForwardMetric1=10 and dwForwardType=4
Sat Jan 16 13:42:41 2016 Route addition via IPAPI succeeded [adaptive]
Sat Jan 16 13:42:41 2016 C:\Windows\system32\route.exe ADD 0.0.0.0 MASK 128.0.0.0 10.8.0.5
Sat Jan 16 13:42:41 2016 ROUTE: CreateIpForwardEntry succeeded with dwForwardMetric1=20 and dwForwardType=4
Sat Jan 16 13:42:41 2016 Route addition via IPAPI succeeded [adaptive]
Sat Jan 16 13:42:41 2016 C:\Windows\system32\route.exe ADD 128.0.0.0 MASK 128.0.0.0 10.8.0.5
Sat Jan 16 13:42:41 2016 ROUTE: CreateIpForwardEntry succeeded with dwForwardMetric1=20 and dwForwardType=4
Sat Jan 16 13:42:41 2016 Route addition via IPAPI succeeded [adaptive]
Sat Jan 16 13:42:41 2016 MANAGEMENT: >STATE:1452969761,ADD_ROUTES,,,
Sat Jan 16 13:42:41 2016 C:\Windows\system32\route.exe ADD 10.8.0.0 MASK 255.255.255.0 10.8.0.5
Sat Jan 16 13:42:41 2016 ROUTE: CreateIpForwardEntry succeeded with dwForwardMetric1=20 and dwForwardType=4
Sat Jan 16 13:42:41 2016 Route addition via IPAPI succeeded [adaptive]
Sat Jan 16 13:42:41 2016 Initialization Sequence Completed
Sat Jan 16 13:42:41 2016 MANAGEMENT: >STATE:1452969761,CONNECTED,SUCCESS,10.8.0.6,45.63.70.25

Traffic

According to your log you are connected normally.

I suggest you work carefully through the HOWTO:
HOWTO: Routing all client traffic (including web-traffic) through the VPN

sambeniii

Hmmm, I've already applied the information found within that lank to the server, and I still get nothing. I believe the configuration of the OpenVPN tunnel is fine, it has something to do with the server not properly routing the packets out when they arrive, and sending them back correctly. Any ideas?

Traffic

sambeniii wroteI greatly appreciate any help that can be given, and will submit logs or other config files if the need be

Server iptables rules, server ifconfig & server route table .. tracert -d 8.8.8.8 from the client.

sambeniii

Alright, in the order requested, first iptables rules lists

Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy DROP)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination
MASQUERADE  all  --  10.8.0.0/24          anywhere

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         [Server's Gateway]      0.0.0.0         UG    100    0        0 eth0
10.8.0.0        0.0.0.0         255.255.255.0   U     0      0        0 tun0
[Server's pub IP]      0.0.0.0         255.255.254.0   U     0      0        0 eth0
[Server's pub IP]     0.0.0.0         255.255.254.0   U     100    0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     100    0        0 eth0
169.254.169.254 45.63.70.1      255.255.255.255 UGH   100    0        0 eth0

And finally the failed traceroute, I assume this would go one indefinetly, so here's the first 10 jumps failing.

Tracing route to 8.8.8.8 over a maximum of 30 hops

  1    32 ms    32 ms    33 ms  10.8.0.1 
  2     *        *        *     Request timed out.
  3     *        *        *     Request timed out.
  4     *        *        *     Request timed out.
  5     *        *        *     Request timed out.
  6     *        *        *     Request timed out.
  7     *        *        *     Request timed out.
  8     *        *        *     Request timed out.
  9     *        *        *     Request timed out.
 10     *        *        *     Request timed out.

Traffic

I presume IP forwarding is enabled on your server ?

sambeniii

By IP Forwarding being enabled that would be accomplished by having the following in my sysctl.conf?

net.ipv4.ip_forward = 1[code]