Networking concepts - Revision history

Lilith2 at 19:53, 9 October 2015

2015-10-09T19:53:04Z

Lilith2: /* Application protocols */

2015-09-05T16:48:55Z

‎Application protocols

Lilith2: /* Internet Control Message Protocol (ICMP) */

2015-08-31T08:14:57Z

‎Internet Control Message Protocol (ICMP)

Lilith2: /* Hubs and switches */

2015-08-13T17:18:54Z

‎Hubs and switches

Lilith2 at 17:15, 13 August 2015

2015-08-13T17:15:40Z

Lilith2: /* Hubs and switches */

2015-08-13T17:13:21Z

‎Hubs and switches

Lilith2: /* Hubs and switches */

2015-08-13T17:11:39Z

‎Hubs and switches

Lilith2: /* Mixnets */

2015-08-12T18:17:02Z

‎Mixnets

Lilith2: /* Resources */

2015-08-12T18:16:06Z

‎Resources

Lilith2: /* Mix networks */

2015-08-12T17:45:33Z

‎Mix networks

@@ Line 1,065: / Line 1,065: @@
 === Security ===
-Most routers come with the option to set the router to ignore or drop ICMP redirects because they can be used to attack networks by confusing hosts as to where the correct default gateway is. ICMP redirects may also be used to amplify SMURF or FRAGGLE attacks or to set up Man-in-the-Middle attacks.
+Most routers come with the option to set the router to ignore or drop ICMP redirects because they can be used to attack networks by confusing hosts as to where the correct default gateway is. ICMP redirects may also be used to set up Man-in-the-Middle attacks.
 The variable size of the ICMP packet data section has been exploited a lot. In the well-known "Ping of death," large or fragmented ping packets are used for denial-of-service attacks. ICMP can also be used to create covert channels for communication (see LOKI exploit). When people talk about blocking ICMP they're really talking about <code>ping</code> and <code>traceroute</code>. ''Ping'' can be used to determine if a host is alive, ''Time Exceeded'' (as part of a traceroute) can be used to to map out network architectures, or void forbid a ''Redirect'' (type 5 code 0) to change the default route of a host.

@@ Line 291: / Line 291: @@
 FTP, TFTP, SMTP, Telnet, NFS, ping, rlogin provide direct services to the user. DNS provides address to name translation for locations and network cards. RPC allows remote computer to perform functions on other computers. RARP, BOOTP, DHCP, IGMP, SNMP,RIP, OSPF, BGP, and CIDR enhance network management and increase functionality.
 * ''Hypertext Transfer Protocol (HTTP)'' is the protocol that facilitates transfer of data. Typically, data is transferred in the form of pages, or HTML markup. HTTP operates on TCP port 80.
-* ''Secure HTTP (HTTPS)'' uses TCP port 443 to securely transfer HTTP data via SSL, or Secure Socket Layer. TLS is the newer SSL.
+* ''Secure HTTP (HTTPS)'' uses TCP port 443 to securely transfer HTTP data via SSL, or Secure Socket Layer. [[Digital_threats,_detection,_protection_and_(counter)_moves#TLS.2FSSL|TLS]] is the newer SSL.
 * ''File Transfer Protocol (FTP)'' operates on TCP ports 20 (data)/21(transmission control). It is used in simple file transfers from one node to another without any security (transferred in cleartext). Secure (SFTP) is a version of FTP that uses SSH to transfer data securely, using whichever port SSH uses (usually 22).
 * ''Trivial FTP (TFTP)'' is a UDP version of FTP that uses UDP port 69. It is called "trivial" because it is relatively unreliable and inefficient and so is more often used for inter-network communication between routers.

@@ Line 1,073: / Line 1,073: @@
 * Active Directory requires clients ping the domain controllers in order to pull down GPOs. They use ping to determine the "closest" controller and if none respond, then it is assumed that none are close enough. So the policy update doesn't happen.
-Blocking ICMP in its entirety is probably not a good idea, picking and choosing what to block and to/from where, probably will get us what we want.
+Blocking ICMP in its entirety is probably not a good idea, picking and choosing what to block and to/from where, probably will get us what we want. See [[Linux_security#Making_the_rules|ufw rules]] and [[Linux_security#Making_the_rules_2|iptables rules]].
 == Simple routing ==

@@ Line 73: / Line 73: @@
 A ''network hub'' is a hardware device to connect network devices together. The devices will all be on the same network and/or subnet. All network traffic is shared and can be sniffed by any other node connected to the same hub.
-An '''uplink''' is a connection from a device or smaller local network to a larger network. ''Uplink'' does not have a crossover connection and is designed to fit into a crossover connection on the next hub. This way you can keep linking hubs to put more computers on a network. Because each hub introduces some delay onto the network signals, there is a limit to the number of hubs you can sequentially link. Also the computers that are connected to the two hubs are on the same network and can talk to each other. All network traffic including all broadcasts is passed through the hubs.
+An ''uplink'' is a connection from a device or smaller local network to a larger network. ''Uplink'' does not have a crossover connection and is designed to fit into a crossover connection on the next hub. This way you can keep linking hubs to put more computers on a network. Because each hub introduces some delay onto the network signals, there is a limit to the number of hubs you can sequentially link. Also the computers that are connected to the two hubs are on the same network and can talk to each other. All network traffic including all broadcasts is passed through the hubs.
 A ''network switch'' is like a hub but creates a private link between any two connected nodes when a network connection is established. This reduces the amount of network collisions and thus improves speed. Broadcast messages are still sent to all nodes.

@@ Line 3: / Line 3: @@
 ''Dandy it may be to speak about such "access" entitlements to internet power, till one realises the range of forces at work seeking to limit and restrict its operations. They come from governments and their agencies. They come from companies and their subsidiaries. The internet, in other words, is simply another territory of conflict, and one filled with fractious contenders vying for the shortest lived of primacies. Forget neutrality – it was never there to begin with. Just ask the lawyers getting their briefs ready for the next round of dragging litigation.'' ~ The FCC, the Internet and Net Neutrality <ref>The FCC, the Internet and Net Neutrality http://www.counterpunch.org/2015/03/05/the-fcc-the-internet-and-net-neutrality/</ref>
 [[File:Fcc.jpg|480px|thumb|right|By John Trevor http://editorialcartoonists.com/cartoonist/profile.cfm/TreveJ/]]
 [[File:P2pfoundation.png|480px|thumb|right|http://p2pfoundation.net/Main_Page]]

@@ Line 69: / Line 69: @@
 === Hubs and switches ===
-A ''network hub'' is a hardware device to connect network devices together. The devices will all be on the same network and/or subnet. All network traffic is shared and can be sniffed by any other node connected to the same hub. ''Uplink'' does not have a crossover connection and is designed to fit into a crossover connection on the next hub. This way you can keep linking hubs to put more computers on a network. Because each hub introduces some delay onto the network signals, there is a limit to the number of hubs you can sequentially link. Also the computers that are connected to the two hubs are on the same network and can talk to each other. All network traffic including all broadcasts is passed through the hubs.
+A ''network hub'' is a hardware device to connect network devices together. The devices will all be on the same network and/or subnet. All network traffic is shared and can be sniffed by any other node connected to the same hub.
 A ''network switch'' is like a hub but creates a private link between any two connected nodes when a network connection is established. This reduces the amount of network collisions and thus improves speed. Broadcast messages are still sent to all nodes.

@@ Line 73: / Line 73: @@
 A ''network switch'' is like a hub but creates a private link between any two connected nodes when a network connection is established. This reduces the amount of network collisions and thus improves speed. Broadcast messages are still sent to all nodes.
-If you have a machine (device, computer) with two network cards, eth0, connected to an outbound hub, and eth1, connected to another hub that only connects to local machines, and it is not configured as ''router'' or ''bridge'', the two networks are considered separated. If no other machines on the network that the eth0 card is connected to, is an outbound device, all devices in that network are dependent.
+If you have a machine (device, computer) with two network cards, eth0, connected to an outbound hub, and eth1, connected to another hub that only connects to local machines, and it is not configured as ''router'' or ''bridge'', the two networks are considered separated. If no other machines on the network that the eth0 card is connected to is an outbound device, all devices in that network are dependent.
 [[File:Netconnections2.png|640px|thumb|center|Three hubs, A, B and C, with uplink connections. A can be connected to the internet. As depicted it is not, and as a result all computers are not.]]

@@ Line 1,355: / Line 1,355: @@
 * For Free Information and Open Internet Independent journalists, community media and hacktivists take action” (pdf): PirateBox or How to Escape the Big Brothers of the Internet (mathieu lapprand) – starts on page 143 http://www.coredem.info/IMG/pdf/pass11_an-2.pdf
-=== Mixnets ===
+=== Low-latency onion routing ===
 * HORNET: High-speed Onion Routing at the Network Layer http://arxiv.org/pdf/1507.05724v1.pdf

@@ Line 1,353: / Line 1,353: @@
 === Pirate boxes ===
 * For Free Information and Open Internet Independent journalists, community media and hacktivists take action” (pdf): PirateBox or How to Escape the Big Brothers of the Internet (mathieu lapprand) – starts on page 143 http://www.coredem.info/IMG/pdf/pass11_an-2.pdf
 == Related ==

@@ Line 1,232: / Line 1,232: @@
 == Mix networks ==
-In the eighties, David Chaum invented the principle of digital mixes (sometimes called mix networks or mixnets) to achieve a higher level of anonymity with personal communication. Digital mixing uses a similar system as routing but it adds several layers in the connection between the sender and receiver of the communication. The layers are created using [[Encrypting_everything#Asymmetric_key_encryption|public key cryptography]]. Using digital mixing is comparable to sending a letter encased in four envelopes pre-addressed and pre-stamped with a small message reading, "please remove this envelope and repost".
+In the eighties, digital mixes (sometimes called mix networks or mixnets) to achieve a higher level of anonymity with personal communication appeared. Digital mixing uses a similar system as routing but it adds several layers in the connection between the sender and receiver of the communication. The layers are created using [[Encrypting_everything#Asymmetric_key_encryption|public key cryptography]]. Using digital mixing is comparable to sending a letter encased in four envelopes pre-addressed and pre-stamped with a small message reading, "please remove this envelope and repost".
 Note: ''Mixnets are not designed to disguise the fact that you are using a mix network. If an adversary can simply lock you up for using anonymity tools, you need to disguise your use of anonymity tools.''