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[gelöst] Grundlagen OpenVPN

Becksta

Hacker
Servus und Hallo...

ich habe meinen SuseServer endlich als Gateway eingerichtet bekommen.
Hinter der Fritzbox macht also jetzt der SuseServer alles. DNS, DHCP, und seit ein paar Tagen auch einen OpenVPN Server.
Damit habe ich allerdings keinerlei Erfahrungen, was auch fürs Routing gilt. Daher kommen vermutlich auch meine Probleme... hehe

Ich kann mich aktuell per VPN von meinem LinuxMint Notebook via UMTS mit meinem Server verbinden. Die Weiterleitung der Ports, bzw. die Freigabe klappt wohl. Allerdings kann ich nach erfolgreicher Verbindung keinen Rechner anpingen.

Weder den VPN Server über die VPN IP (10.8.0.1), noch mein lokales LAN (192.168.2.0). Ich habe schon mal die "push" Funktion aktiviert, aber die hat es auch nicht gebracht.

Was genau muss ich machen, damit ich via VPN alle Rechner im lokalen Netz erreichen kann?
Muss ich dafür zwingen das "tun device" bridgen?

Habe auf dem Suseserver auch schon mal ein Route ins Netz 10.8.0.0 eingerichtet, dazu noch ein Frage:
Welches Gateway muss ich beim Anlagen einer statischen Route angeben??

Greetz
Becksta
 
OP
Becksta

Becksta

Hacker
hier mal meine Config:

server.conf:
Code:
# 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 /etc/openvpn/easy-rsa/2.0/keys/ca.crt
cert /etc/openvpn/easy-rsa/2.0/keys/suseserver.becksta.de.crt
key /etc/openvpn/easy-rsa/2.0/keys/suseserver.becksta.de.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 /etc/openvpn/easy-rsa/2.0/keys/dh1024.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

# 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 192.168.2.0 255.255.255.0"
;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 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

# 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

Mit welchem Befehl lese ich auf der Konsole die iptables Config aus??

Ich habe unter Yast folgende Route in den Netzwerkeinstellungen hinterlegt:
Ziel: 10.8.0.0 Netzmaske: 255.255.255.0 Gateway:192.168.2.1 (SuseServer)

Welche Dateien sind noch für die Fehlersuche hilfreich??
Muss auf der Clientseite auch eine Route hinterlegt werden, oder reichen die serverseitigen Einstellungen?

Greetz
Becksta
 

framp

Moderator
Teammitglied
Sorry - Dein Post ist mir zu lang zum Lesen.
Code:
egrep -v "^$|^#" server.conf
wirkt da Wunder ;-)
 

spoensche

Moderator
Teammitglied
Die aktuellen IP-Tables Regeln kannst du dir mit

Code:
/usr/sbin/iptables -L

ausgeben lassen.

Für eine Fehleranalyse sind die Inhalte der Logfiles und auch die Netzstruktur sehr hilfreich.

Evtl. hilft dir auch http://openvpn.net/index.php/open-source/documentation.html
 
OP
Becksta

Becksta

Hacker
Aloa,

also ich habe einen Fehler bei der Client Konfiguration gemacht, dort war die Compression deaktiviert.
Jetzt kann ich die anderen Teilnehmer im lokalen Netz anpingen und mich auch via ssh auf meinem Server einloggen.

Was muss ich denn noch machen, damit ich auch auf die Samba Freigaben oder den Apache zugreifen kann?
Das funktioniert noch nicht.

Hier mal die server.conf:
Code:
port 1194
proto udp
dev tun
ca /etc/openvpn/easy-rsa/2.0/keys/ca.crt
cert /etc/openvpn/easy-rsa/2.0/keys/suseserver.becksta.de.crt
key /etc/openvpn/easy-rsa/2.0/keys/suseserver.becksta.de.key  # This file should be kept secret
dh /etc/openvpn/easy-rsa/2.0/keys/dh1024.pem
server 10.8.0.0 255.255.255.0
keepalive 10 120
comp-lzo
persist-key
persist-tun
status openvpn-status.log
verb 3

/var/log/messages beim Aufbau der Verbindung:
Code:
Mar 19 17:20:21 suseserver openvpn[25906]: MULTI: multi_create_instance called
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 Re-using SSL/TLS context
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 LZO compression initialized
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 Control Channel MTU parms [ L:1542 D:138 EF:38 EB:0 ET:0 EL:0 ]
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 Data Channel MTU parms [ L:1542 D:1450 EF:42 EB:135 ET:0 EL:0 AF:3/1 ]
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 Local Options hash (VER=V4): '530fdded'
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 Expected Remote Options hash (VER=V4): '41690919'
Mar 19 17:20:21 suseserver openvpn[25906]: 109.250.81.160:49375 TLS: Initial packet from 109.250.81.160:49375, sid=347c2e38
c0f13094
Mar 19 17:20:27 suseserver openvpn[25906]: 109.250.81.160:49375 VERIFY OK: depth=1, 
Mar 19 17:20:27 suseserver openvpn[25906]: 109.250.81.160:49375 VERIFY OK: depth=0, 
Mar 19 17:20:29 suseserver openvpn[25906]: 109.250.81.160:49375 Data Channel Encrypt: Cipher 'BF-CBC' initialized with 128 bit key
Mar 19 17:20:29 suseserver openvpn[25906]: 109.250.81.160:49375 Data Channel Encrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Mar 19 17:20:29 suseserver openvpn[25906]: 109.250.81.160:49375 Data Channel Decrypt: Cipher 'BF-CBC' initialized with 128 bit key
Mar 19 17:20:29 suseserver openvpn[25906]: 109.250.81.160:49375 Data Channel Decrypt: Using 160 bit message hash 'SHA1' for HMAC authentication
Mar 19 17:20:29 suseserver openvpn[25906]: 109.250.81.160:49375 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA
Mar 19 17:20:29 suseserver openvpn[25906]: 109.250.81.160:49375 [beckstanotebook.becksta.de] Peer Connection Initiated with 109.250.81.160:49375
Mar 19 17:20:29 suseserver openvpn[25906]: MULTI: new connection by client 'beckstanotebook.becksta.de' will cause previous active sessions by this client to be dropped.  Remember to use the --duplicate-cn option if you want multiple clients using the same certificate or username to concurrently connect.
Mar 19 17:20:29 suseserver openvpn[25906]: MULTI: Learn: 10.8.0.6 -> beckstanotebook.becksta.de/109.250.81.160:49375
Mar 19 17:20:29 suseserver openvpn[25906]: MULTI: primary virtual IP for beckstanotebook.becksta.de/109.250.81.160:49375: 10.8.0.6
Mar 19 17:20:30 suseserver openvpn[25906]: beckstanotebook.becksta.de/109.250.81.160:49375 PUSH: Received control message: 'PUSH_REQUEST'
Mar 19 17:20:30 suseserver openvpn[25906]: beckstanotebook.becksta.de/109.250.81.160:49375 SENT CONTROL [beckstanotebook.becksta.de]: 'PUSH_REPLY,route 192.168.2.0 255.255.255.0,route 10.8.0.1,topology net30,ping 10,ping-restart 120,ifconfig 10.8.0.6 10.8.0.5' (status=1)

Auf dem Client wird noch ein Hinweis zum "tun0" Device ausgespuckt:

Code:
 tun0: Disabled Privacy Extensions

Muss ich für den Zugriff auf den Samba usw. das TAP Device einrichten?

Greetz
Becksta
 
OP
Becksta

Becksta

Hacker
OK,

das Stichwort für den Samba lautet "hosts allow", bzw. "interfaces".
Allerdings konnte ich dann immer noch nicht direkt drauf zugreifen.

Bei der Kontrolle der Firewalleinstellungen via Yast ist mir dann aufgefallen, dass in der externen Zone der Zugriff für ssh offen war. Konnte mich ja auch mit ssh verbinden. Als ich da den Samba auch noch freigegeben habe, ging es auch.

Ich frage mich nur, ob das nicht potenziell fragwürdig ist. Müsste das tun0 Device nicht eigentlich der internen Zone zugewiesen werden können???

Allerdings sehe ich in den Einstellungen der Firewall überhaupt kein tun Device... Auch unter /etc/sysconfig/network exisitiert dazu keine Datei. Es wäre schön, wenn mir dazu noch jemand eine kleine Hilfestellung geben könnte.

Nur noch mal zum Verständnis:

Die FritzBox baut (noch) die Internetverbindung auf, ist als das Gateway auf eth1 für den Suseserver, weshalb das Device eth1 auch der externen Zone zugewiesen ist. eth0 ist das interne LAN. IP-Weiterleitung klappt soweit.

Ich frage mich nur, warum ich zum Beispiel den Apache erreichen kann, obwohl der in der externen Zone nicht als Dienst freigegeben ist. Habe lediglich den Port 80 in der FritzBox an den Server weitergeleitet. Wie gesagt: Firewall Themen sind nicht meine große Stärke... *g*

Greetz
Becksta
 
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