0

I have ubuntu server on which I want to create VPN access. For that I am using OpenVPN. Also for tutorial I am reading this one: tutorial The problem is that when I blocked the traffice with iptables and connect with vpn client to the server one again I cannot open the server from the browser. SSH access still I have. In this server also I am using docker containers to run my images. So the question is Are there any mistakes in this tutorial which I am doing wrong?

server.conf file

    #################################################
    # 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 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 wserver.crt
    key wserver.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"
    # Clients are to use this server as a network gateway.
    push "redirect-gateway def1"
    # 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 208.67.222.222"
    push "dhcp-option DNS 208.67.220.220"

    # 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
    key-direction 0

    # Select a cryptographic cipher.
    # This config item must be copied to
    # the client config file as well.
    ;cipher BF-CBC        # Blowfish (default)
    cipher AES-256-CBC   # AES
    ;cipher DES-EDE3-CBC  # Triple-DES
    auth SHA256

    # 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

ipaddress details

    root@scw-71f02e:~# ip addr show
    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
        inet 127.0.0.1/8 scope host lo
           valid_lft forever preferred_lft forever
        inet6 ::1/128 scope host 
           valid_lft forever preferred_lft forever
    2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
        link/ether de:19:68:1a:10:02 brd ff:ff:ff:ff:ff:ff
        inet 10.4.107.133/31 brd 10.4.107.133 scope global eth0
           valid_lft forever preferred_lft forever
        inet6 fe80::dc19:68ff:fe1a:1002/64 scope link 
           valid_lft forever preferred_lft forever
    3: ip6_vti0@NONE: <NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1
        link/tunnel6 :: brd ::
    4: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1
        link/sit 0.0.0.0 brd 0.0.0.0
    5: ip6tnl0@NONE: <NOARP> mtu 1452 qdisc noop state DOWN group default qlen 1
        link/tunnel6 :: brd ::
    7: br-7a0b6054cfcc: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:87:1f:78:92 brd ff:ff:ff:ff:ff:ff
        inet 172.19.0.1/16 scope global br-7a0b6054cfcc
           valid_lft forever preferred_lft forever
        inet6 fe80::42:87ff:fe1f:7892/64 scope link 
           valid_lft forever preferred_lft forever
    8: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:4e:9e:0e:a3 brd ff:ff:ff:ff:ff:ff
        inet 172.17.0.1/16 scope global docker0
           valid_lft forever preferred_lft forever
        inet6 fe80::42:4eff:fe9e:ea3/64 scope link 
           valid_lft forever preferred_lft forever
    9: br-a9f47349cd0a: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:69:80:40:ff brd ff:ff:ff:ff:ff:ff
        inet 172.20.0.1/16 scope global br-a9f47349cd0a
           valid_lft forever preferred_lft forever
        inet6 fe80::42:69ff:fe80:40ff/64 scope link 
           valid_lft forever preferred_lft forever
    10: br-eadb628ff757: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
        link/ether 02:42:b8:29:a5:5b brd ff:ff:ff:ff:ff:ff
        inet 172.18.0.1/16 scope global br-eadb628ff757
           valid_lft forever preferred_lft forever
        inet6 fe80::42:b8ff:fe29:a55b/64 scope link 
           valid_lft forever preferred_lft forever
    12: veth43bacbe@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-7a0b6054cfcc state UP group default 
        link/ether 16:8a:ad:ea:61:45 brd ff:ff:ff:ff:ff:ff link-netnsid 4
        inet6 fe80::148a:adff:feea:6145/64 scope link 
           valid_lft forever preferred_lft forever
    14: veth6643630@if13: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-a9f47349cd0a state UP group default 
        link/ether 2e:aa:81:6f:54:e9 brd ff:ff:ff:ff:ff:ff link-netnsid 11
        inet6 fe80::2caa:81ff:fe6f:54e9/64 scope link 
           valid_lft forever preferred_lft forever
    16: vetha1e6703@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-7a0b6054cfcc state UP group default 
        link/ether e2:ea:24:f9:9e:b8 brd ff:ff:ff:ff:ff:ff link-netnsid 3
        inet6 fe80::e0ea:24ff:fef9:9eb8/64 scope link 
           valid_lft forever preferred_lft forever
    18: veth5f6842b@if17: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-7a0b6054cfcc state UP group default 
        link/ether d2:b1:ad:11:5a:8e brd ff:ff:ff:ff:ff:ff link-netnsid 5
        inet6 fe80::d0b1:adff:fe11:5a8e/64 scope link 
           valid_lft forever preferred_lft forever
    20: veth6356df6@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-eadb628ff757 state UP group default 
        link/ether 86:67:ab:6c:e1:c6 brd ff:ff:ff:ff:ff:ff link-netnsid 2
        inet6 fe80::8467:abff:fe6c:e1c6/64 scope link 
           valid_lft forever preferred_lft forever
    22: veth8ee8fd4@if21: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-a9f47349cd0a state UP group default 
        link/ether ca:86:b4:05:21:4b brd ff:ff:ff:ff:ff:ff link-netnsid 8
        inet6 fe80::c886:b4ff:fe05:214b/64 scope link 
           valid_lft forever preferred_lft forever
    24: vetha3581cf@if23: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
        link/ether a6:d4:56:34:28:83 brd ff:ff:ff:ff:ff:ff link-netnsid 0
        inet6 fe80::a4d4:56ff:fe34:2883/64 scope link 
           valid_lft forever preferred_lft forever
    26: vethee6d4a4@if25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-eadb628ff757 state UP group default 
        link/ether 9a:f3:52:d1:77:24 brd ff:ff:ff:ff:ff:ff link-netnsid 1
        inet6 fe80::98f3:52ff:fed1:7724/64 scope link 
           valid_lft forever preferred_lft forever
    28: vethbebf7e8@if27: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br-eadb628ff757 state UP group default 
        link/ether b6:de:90:76:61:92 brd ff:ff:ff:ff:ff:ff link-netnsid 9
        inet6 fe80::b4de:90ff:fe76:6192/64 scope link 
           valid_lft forever preferred_lft forever
    31: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 100
        link/none 
        inet 10.8.0.1 peer 10.8.0.2/32 scope global tun0
           valid_lft forever preferred_lft forever
        inet6 fe80::42c1:4b65:65f9:1bcb/64 scope link flags 800 
           valid_lft forever preferred_lft forever

My goal is to access all docker instances - jenkins, nexus, portainer, DB etc. only through VPN.

client_machine ------> VPN --->Docker containers

And this I do not want: client_machine ------X----> Docker-containers

This is the iptables:

        Chain INPUT (policy ACCEPT)
    num  target     prot opt source               destination         
    1    ACCEPT     all  --  anywhere             anywhere            
    2    REJECT     all  --  127.0.0.0/8          anywhere             reject-with icmp-port-unreachable
    3    ACCEPT     icmp --  anywhere             anywhere             state NEW icmp echo-request
    4    ACCEPT     icmp --  anywhere             anywhere             state RELATED,ESTABLISHED
    5    ACCEPT     tcp  --  anywhere             anywhere             state NEW,ESTABLISHED tcp dpt:ssh
    6    ACCEPT     udp  --  anywhere             anywhere             state NEW,ESTABLISHED udp dpt:openvpn
    7    ACCEPT     udp  --  anywhere             anywhere             state ESTABLISHED udp spt:domain
    8    ACCEPT     tcp  --  anywhere             anywhere             state ESTABLISHED tcp spt:domain
    9    ACCEPT     tcp  --  anywhere             anywhere             state ESTABLISHED tcp spt:http
    10   ACCEPT     tcp  --  anywhere             anywhere             state ESTABLISHED tcp spt:https
    11   ACCEPT     all  --  anywhere             anywhere            
    12   LOG        all  --  anywhere             anywhere             limit: avg 3/min burst 5 LOG level warning prefix "iptables_INPUT_denied: "
    13   REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable

    Chain FORWARD (policy DROP)
    num  target     prot opt source               destination         
    1    ACCEPT     all  --  anywhere             anywhere            
    2    ACCEPT     all  --  10.8.0.0/24          anywhere            
    3    ACCEPT     all  --  anywhere             anywhere             state RELATED,ESTABLISHED
    4    LOG        all  --  anywhere             anywhere             limit: avg 3/min burst 5 LOG level warning prefix "iptables_FORWARD_denied: "
    5    REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable

    Chain OUTPUT (policy ACCEPT)
    num  target     prot opt source               destination         
    1    ACCEPT     all  --  anywhere             anywhere            
    2    ACCEPT     icmp --  anywhere             anywhere            
    3    ACCEPT     tcp  --  anywhere             anywhere             state ESTABLISHED tcp spt:ssh
    4    ACCEPT     udp  --  anywhere             anywhere             state ESTABLISHED udp spt:openvpn
    5    ACCEPT     udp  --  anywhere             anywhere             state NEW,ESTABLISHED udp dpt:domain
    6    ACCEPT     tcp  --  anywhere             anywhere             state NEW,ESTABLISHED tcp dpt:domain
    7    ACCEPT     tcp  --  anywhere             anywhere             state NEW,ESTABLISHED tcp dpt:http
    8    ACCEPT     tcp  --  anywhere             anywhere             state NEW,ESTABLISHED tcp dpt:https
    9    ACCEPT     all  --  anywhere             anywhere            
    10   LOG        all  --  anywhere             anywhere             limit: avg 3/min burst 5 LOG level warning prefix "iptables_OUTPUT_denied: "
    11   REJECT     all  --  anywhere             anywhere             reject-with icmp-port-unreachable
  • 2
    Rather than just listing the tutorial, why don't you edit your question to include your config, your server ip details, and what you want to achieve (i.e. where you want to restrict the VPN access to, or where you don't want to use the VPN, etc.) – EightBitTony Nov 14 '17 at 8:52
  • 1
    @EightBitTony Thanks I updated the question. – Jordan Borisov Nov 14 '17 at 11:02
1

You need to add push "redirect-gateway def1" to configuration file of the server.

With this option all clients traffic will be redirect through the VPN connection.

  • and also this will hide docker ip address behind the VPN ip address? – Jordan Borisov Nov 26 '17 at 21:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.