OpenVPN: IPv4 routed LAN - Revision history

Onnowpurbo: /* Teori */

2020-03-31T03:31:39Z

Teori

Onnowpurbo: /* Teori */

2020-03-31T03:10:35Z

Teori

Onnowpurbo: /* Teori */

2020-03-31T03:09:41Z

Teori

Onnowpurbo: /* Pranala Menarik */

2020-03-31T01:17:58Z

Pranala Menarik

Onnowpurbo: /* gwA */

2019-02-17T01:32:41Z

gwA

Onnowpurbo at 23:20, 16 February 2019

2019-02-16T23:20:43Z

Onnowpurbo: Created page with "Sumber: https://backreference.org/2009/11/15/openvpn-and-iroute/ ==Referensi== * https://backreference.org/2009/11/15/openvpn-and-iroute/ ==Pranala Menarik== * OpenVPN"

2019-02-16T10:45:31Z

Created page with "Sumber: https://backreference.org/2009/11/15/openvpn-and-iroute/ ==Referensi== * https://backreference.org/2009/11/15/openvpn-and-iroute/ ==Pranala Menarik== * OpenVPN"

New page

Sumber: https://backreference.org/2009/11/15/openvpn-and-iroute/

==Referensi==

* https://backreference.org/2009/11/15/openvpn-and-iroute/

==Pranala Menarik==

* [[OpenVPN]]

@@ Line 77: / Line 77: @@
   iroute
-ini diletakan dalam file2 di bawah folder
+Dalam contoh ini, diletakan dalam file2 di bawah folder
   /etc/openvpn/ccd/

← Older revision		Revision as of 03:10, 31 March 2020
Line 76:		Line 76:

	iroute		iroute
		+
		+	ini diletakan dalam file2 di bawah folder
		+
		+	/etc/openvpn/ccd/

	==Referensi==		==Referensi==

@@ Line 59: / Line 59: @@
-At this point, some background on how OpenVPN works internally is in order.
+Berikut ini, sedikit teori / latar belakang bagaimana OpenVPN bekerja.
-If the IP addresses involved are only those belonging to the VPN, OpenVPN has no trouble to associate a certain VPN IP to the public IP address of a remote VPN peer (as long as the addresses were pushed by the server to the clients and not statically assigned).
+Saat OpenVPN menerima sebuah paket / frame pada interface tun/tap untuk di forward, maka OpenVPN akan meng-enkript paket tersebut dan meng-enkapsulasi-nya menjadi satu atau lebih UDP datagram, yang kemudian dikirim ke remote (biasanya public) IP address dari VPN node lain. VPN Node tersebut akan menerima di IP public-nya, meng-dekapsulasi dan dekript paket / frame tersebut, dan mengirimkan paket tersebut ke interface tun/tap lokal, dimana packet tersebut akan akhirnya berinteraksi dengan sistem operasi di komputer remote tersebut. Tentu saja proses ini juga berlaku untuk arah yang berlawanan.
-However, when non-VPN packets are involved, OpenVPN needs more information. In our A-to-C example, when gwA receives the packet with src=192.168.1.1 and dst=192.168.3.1, the routing table sends it to the tun0 interface, and thus to OpenVPN. Now, how does OpenVPN know behind which remote peer that destination IP is? That is a necessary piece of information it needs in order to know the destination IP to use for the encapsulating UDP packets.
+Jika IP address yang terlibat disini hanya milik VPN saja, OpenVPN tidak akan memperoleh masalah untuk mengasosiasikan sebuah IP VPN ke IP public milik remote VPN peer (selama address ini di push oleh server ke client dan tidak secara statik dialokaikan).
-Similarly, in the C-to-A direction, when gwA's OpenVPN sees a packet with src=192.168.3.1 and dst=192.168.1.1, it needs to make sure that it knows how to reach the source address, in order to send replies later. So it's just a different aspect of the same problem.
+Yang akan menjadi masalah, jika ada non-VPN paket yang terlibat, OpenVPN membutuhkan informasi lebih lanjut. Untuk kasus kita antara A-to-C, jika gwA menerima paket dengan src=192.168.1.1 dan dst=192.168.3.1, maka tabel routing akan mengirimkannya ke interface tun0, dan kemudian ke OpenVPN. Pertanyaannya, bagaimana OpenVPN bisa tahu destination IP berada di belakang remote peer yang mana? Informasi ini diperlukan agar OpenVPN dapat meng-enkapsulasi UDP Paket ke IP remote OpenVPN yang benar.
-Since there can be (and there actually is) more than one peer, OpenVPN needs to know which network is behind each peer. You might think (as I naively did) that it should be able to somehow infer that information from the routes in the routing table, for example since gwA has this route in the routing table
+Hal yang sama, untuk arah C-to-A, saat OpenVPN gwA melihat paket dengan src=192.168.3.1 dan dst=192.168.1.1, OpenVPN gwA membutuhkan informasi bagaimana untuk mencapai source address, agar nantinya dapat mengirim reply. Jadi ini masalah yang sama dengan diatas, hanya dari sudut pandang yang berbeda.
 .168.3.0/24 via 10.0.0.3 dev tun0
-it could assume that 192.168.3.0/24 is behind 10.0.0.3, and thus use gwC's public IP to send encapsulated traffic destined to 192.168.3.0/24. Well, it seems that it doesn't work that way. You have to explicitly tell OpenVPN which network is behind each client. This is where our iroute directive comes into play.
+yang akan mengasumsikan bahwa 192.168.3.0/24 berada di belakang 10.0.0.3, dan akan menggunakan gwC public IP untuk mengirimkan encapsulated traffic yang ditujukan ke 192.168.3.0/24. Sayangnya, OpenVPN tidak bekerja seperti itu. Kita perlu secara explisit memberitahukan OpenVPN network mana dibelakang setiap client. Ini dilakukan menggunakan directive
 ==Referensi==

← Older revision		Revision as of 01:17, 31 March 2020
Line 81:		Line 81:
	==Pranala Menarik==		==Pranala Menarik==

−	* [[OpenVPN]]	+	* [[OpenVPN: IPv4 /32 single client]]
		+	* [[OpenVPN: IPv4 /32 multi-client]]
		+	* [[OpenVPN: IPv4 routed LAN]]
		+	* [[OpenVPN: IPv4 routed 2 LAN]]
		+	* [[OpenVPN: IPv6 /128 single client]]
		+	* [[OpenVPN: IPv6 routed LAN]]
		+	* [[OpenVPN: IPv6 routed 2 LAN]]
		+
		+	* [[IPv6: OpenVPN: Ubuntu roadwarrior]]
		+	* [[OpenVPN: Simple Server using Script]]
		+	* [[OpenVPN: Free VPN untuk Ubuntu]]
		+	* [[Instalasi OpenVPN]]
		+	* [[Instalasi OpenVPN Client di Linux]]
		+	* [[Capture Screen Proses Instalasi OpenVPN di Windows]]
		+	* [[Instalasi OpenVPN di Windows]]
		+	* [[WNDW: OpenVPN]]
		+	* [[OpenVPN: Instalasi di Ubuntu 16.04]]
		+	* [[OpenVPN: Instalasi di Ubuntu 18.04]]
		+	* [[OpenVPN: Briding dan Routing]]

@@ Line 23: / Line 23: @@
   ifconfig-push 10.0.0.2 255.255.255.0
   push "route 192.168.1.0 255.255.255.0 10.0.0.1"
   gwA # cat /etc/openvpn/ccd/gwC
   ifconfig-push 10.0.0.3 255.255.255.0
   push "route 192.168.1.0 255.255.255.0 10.0.0.1"
+ iroute 192.168.3.0 255.255.255.0
 ==gwB==

← Older revision		Revision as of 23:20, 16 February 2019
Line 1:		Line 1:
	Sumber: https://backreference.org/2009/11/15/openvpn-and-iroute/		Sumber: https://backreference.org/2009/11/15/openvpn-and-iroute/

		+	[[File:Iroute.png\|center\|300px\|thumb]]

		+	==gwA==
		+
		+	gwA # cat /etc/openvpn/server.conf
		+	# gwA
		+	local 172.20.0.1
		+	port 1194
		+	proto udp
		+	dev tun
		+	topology subnet
		+	mode server
		+	tls-server
		+	ifconfig 10.0.0.1 255.255.255.0
		+	route 192.168.2.0 255.255.255.0 10.0.0.2
		+	route 192.168.3.0 255.255.255.0 10.0.0.3
		+	client-config-dir ccd
		+	# snip rest of config
		+
		+	gwA # cat /etc/openvpn/ccd/gwB
		+	ifconfig-push 10.0.0.2 255.255.255.0
		+	push "route 192.168.1.0 255.255.255.0 10.0.0.1"
		+	gwA # cat /etc/openvpn/ccd/gwC
		+	ifconfig-push 10.0.0.3 255.255.255.0
		+	push "route 192.168.1.0 255.255.255.0 10.0.0.1"
		+
		+
		+	==gwB==
		+
		+	gwB # cat /etc/openvpn/client.conf
		+	# gwB
		+	remote 172.20.0.1 1194
		+	proto udp
		+	dev tun
		+	topology subnet
		+	# snip rest of config
		+
		+
		+	==gwC==
		+
		+	gwC # cat /etc/openvpn/client.conf
		+	# gwC
		+	remote 172.20.0.1 1194
		+	proto udp
		+	dev tun
		+	topology subnet
		+	# snip rest of config
		+
		+	==Cek==
		+
		+	ping
		+	route
		+
		+	==Teori==
		+
		+
		+	At this point, some background on how OpenVPN works internally is in order.
		+	When OpenVPN receives a packet or frame on the tun/tap interface to forward, it encrypts it and encapsulates it into one or more UDP datagrams, which are then sent out to some remote (usually public) IP address where another VPN node will receive it on its public IP, decapsulate and decrypt them, and send them to the local tun/tap interface, where they will be finally seen by the OS. The process also works in the opposite direction of course.
		+
		+	If the IP addresses involved are only those belonging to the VPN, OpenVPN has no trouble to associate a certain VPN IP to the public IP address of a remote VPN peer (as long as the addresses were pushed by the server to the clients and not statically assigned).
		+
		+	However, when non-VPN packets are involved, OpenVPN needs more information. In our A-to-C example, when gwA receives the packet with src=192.168.1.1 and dst=192.168.3.1, the routing table sends it to the tun0 interface, and thus to OpenVPN. Now, how does OpenVPN know behind which remote peer that destination IP is? That is a necessary piece of information it needs in order to know the destination IP to use for the encapsulating UDP packets.
		+
		+	Similarly, in the C-to-A direction, when gwA's OpenVPN sees a packet with src=192.168.3.1 and dst=192.168.1.1, it needs to make sure that it knows how to reach the source address, in order to send replies later. So it's just a different aspect of the same problem.
		+
		+	Since there can be (and there actually is) more than one peer, OpenVPN needs to know which network is behind each peer. You might think (as I naively did) that it should be able to somehow infer that information from the routes in the routing table, for example since gwA has this route in the routing table
		+
		+	192.168.3.0/24 via 10.0.0.3 dev tun0
		+
		+	it could assume that 192.168.3.0/24 is behind 10.0.0.3, and thus use gwC's public IP to send encapsulated traffic destined to 192.168.3.0/24. Well, it seems that it doesn't work that way. You have to explicitly tell OpenVPN which network is behind each client. This is where our iroute directive comes into play.