diff --git a/doc/networking-guide/section_intro-firewalls.xml b/doc/networking-guide/section_intro-firewalls.xml
index ca72ffe126..6ea880af61 100644
--- a/doc/networking-guide/section_intro-firewalls.xml
+++ b/doc/networking-guide/section_intro-firewalls.xml
@@ -9,12 +9,16 @@
version="5.0"
xml:id="intro-firewalls">
Firewalls
-
- Bacon ipsum dolor sit amet biltong meatloaf andouille, turducken
- bresaola pork belly beef ribs ham hock capicola tail prosciutto
- landjaeger meatball pork loin. Swine turkey jowl, porchetta doner
- boudin meatloaf. Shoulder capicola prosciutto, shank landjaeger short
- ribs sirloin turducken pork belly boudin frankfurter chuck. Salami
- shankle bresaola cow filet mignon ham hock shank.
-
+
+ A firewall is a network security system that controls the
+ network traffic using a set of rules. For example, a firewall might
+ disallow traffic originating from a range of IP addresses or only
+ allow traffic on specific ports. Firewalls are often used between
+ internal networks, where data is trusted, and external networks
+ such as the Internet.
+
+ Many firewalls incorporate Network Address Translation (NAT).
+ Network address translation masks the IP addresses of the devices on
+ the internal network, so that external devices see only the single
+ public IP address of the device hosting the firewall.
diff --git a/doc/networking-guide/section_intro-layers.xml b/doc/networking-guide/section_intro-layers.xml
index a16ffce217..ecb8a0267d 100644
--- a/doc/networking-guide/section_intro-layers.xml
+++ b/doc/networking-guide/section_intro-layers.xml
@@ -9,12 +9,58 @@
version="5.0"
xml:id="intro-layers">
Networking layers
-
- Bacon ipsum dolor sit amet biltong meatloaf andouille, turducken
- bresaola pork belly beef ribs ham hock capicola tail prosciutto
- landjaeger meatball pork loin. Swine turkey jowl, porchetta doner
- boudin meatloaf. Shoulder capicola prosciutto, shank landjaeger short
- ribs sirloin turducken pork belly boudin frankfurter chuck. Salami
- shankle bresaola cow filet mignon ham hock shank.
-
+
+ Network communications is commonly described in terms of the OSI model,
+ a seven-layer model that describes how various protocols and mechanisms fit
+ together. Each layer depends on the protocols in the layer beneath it.
+
+
+
+ 7 Application
+
+ FIXME
+
+
+
+ 6 Presentation
+
+ FIXME
+
+
+
+ 5 Session
+
+ FIXME
+
+
+
+ 4 Transport
+
+ FIXME
+
+
+
+ 3 Network
+
+ FIXME
+
+
+
+ 2 Data link
+
+ FIXME
+
+
+
+ 1 Physical
+
+ FIXME
+
+
+
+
+ OpenStack Networking is primarily concerned with Layer 2 and Layer 3.
+
+ Layer-3 protocols include the Internet Protocal Suite, which includes
+ IPv4, IPv6, and the Internet Control Message Protocol (ICMP).
diff --git a/doc/networking-guide/section_intro-routers.xml b/doc/networking-guide/section_intro-routers.xml
index 8efbaefcd9..ae079ec08a 100644
--- a/doc/networking-guide/section_intro-routers.xml
+++ b/doc/networking-guide/section_intro-routers.xml
@@ -9,12 +9,9 @@
version="5.0"
xml:id="intro-routers">
Routers
-
- Bacon ipsum dolor sit amet biltong meatloaf andouille, turducken
- bresaola pork belly beef ribs ham hock capicola tail prosciutto
- landjaeger meatball pork loin. Swine turkey jowl, porchetta doner
- boudin meatloaf. Shoulder capicola prosciutto, shank landjaeger short
- ribs sirloin turducken pork belly boudin frankfurter chuck. Salami
- shankle bresaola cow filet mignon ham hock shank.
-
+
+ A router is a networking device that connects multiple networks
+ together. Routers are connected to two or more networks. When they
+ receive data packets, they use a routing table to determine which
+ networks to pass the information to.
diff --git a/doc/networking-guide/section_intro-switches.xml b/doc/networking-guide/section_intro-switches.xml
index b8a5a47d89..3b22f5597d 100644
--- a/doc/networking-guide/section_intro-switches.xml
+++ b/doc/networking-guide/section_intro-switches.xml
@@ -9,12 +9,9 @@
version="5.0"
xml:id="intro-switches">
Switches
-
- Bacon ipsum dolor sit amet biltong meatloaf andouille, turducken
- bresaola pork belly beef ribs ham hock capicola tail prosciutto
- landjaeger meatball pork loin. Swine turkey jowl, porchetta doner
- boudin meatloaf. Shoulder capicola prosciutto, shank landjaeger short
- ribs sirloin turducken pork belly boudin frankfurter chuck. Salami
- shankle bresaola cow filet mignon ham hock shank.
-
+
+ A switch is a device that is used to connect devices on a network.
+ Switches forward packets on to other devices, using packet switching to
+ pass data along only to devices that need to receive it. Switches operate
+ at Layer 2 of the OSI model.
diff --git a/doc/networking-guide/section_intro-tunnel.xml b/doc/networking-guide/section_intro-tunnel.xml
index 5933c605ef..2a1f1846c7 100644
--- a/doc/networking-guide/section_intro-tunnel.xml
+++ b/doc/networking-guide/section_intro-tunnel.xml
@@ -9,42 +9,44 @@
version="5.0"
xml:id="intro-tunnel">
Tunnel (segmentation) technologies
-
- Bacon ipsum dolor sit amet biltong meatloaf andouille, turducken
- bresaola pork belly beef ribs ham hock capicola tail prosciutto
- landjaeger meatball pork loin. Swine turkey jowl, porchetta doner
- boudin meatloaf. Shoulder capicola prosciutto, shank landjaeger short
- ribs sirloin turducken pork belly boudin frankfurter chuck. Salami
- shankle bresaola cow filet mignon ham hock shank.
-
+
+ Tunneling allows one network protocol to encapsulate another
+ payload protocol, such that packets from the payload protocol are
+ passed as data on the delivery protocol. This can be used, for
+ example, to pass data securely over an untrusted network.
Layer 2
- VLAN
-
- FIXME
-
+ Virtual local area network (VLAN)
+
+ A VLAN paritions a single layer-2 network into multiple isolated
+ broadcast domains.
+
Layer 3
-
-
- GRE
-
- FIXME
-
-
-
- VLAN
-
- FIXME
-
-
+
+
+
+ Generic routing encapsulation (GRE)
+
+ GRE carries IP packets with private IP address over the Internet
+ using delivery packets with public IP addresses.
+
+
+
+
+ Virtual extensible local area network (VXLAN)
+
+ VXLAN encapsulates layer-2 Ethernet frames over layer-4
+ UDP packets.
+
+