Glossary

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This option enables an HTTP Redirector for proxy usage See: [[HTTPRedirect]] This option enables an HTTP Redirector for proxy usage See: [[HTTPRedirect]]
-===Hotzone=+===Hotzone===
A large [[Glossary#Hotspot| Hotspot]], perhaps covering a whole town A large [[Glossary#Hotspot| Hotspot]], perhaps covering a whole town

Revision as of 03:28, 24 October 2006

Contents: 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
ReferencesExternal links

0-9

802.1x Extensible Authentication Protocol (EAP)

(This entry needs your help.)

802.11b

Channels 1 to 14 (depending on country) in the 2.4GHz range. Operates up to 11Mbits speed. Actual data speed typically 4Mbits, fastest 6Mbits. Further distance than 802.11g

802.11g

Same channels and frequency of 802.11b but with speeds up to 54Mbits, typically actual data speeds are 18Mbits. G equipment is newer and tends to have a better reciever and can be operated as a B only radio. Each channel tends to spread out by a couple of channels ether side. If a foreign channel is as strong as your signal then you need to leave a couple of channels gap.

802.11a

This is the 5.8GHz standard and is subject to more licencing restrictions than the above. The WRT54G is not capable of this, however since dd-wrt is available on hardware with mini-PCI slots these radios could be slotted in.

A

Access Restrictions

(This entry needs your help.)

Adhoc

Adhoc mode, one of the least popular modes, allows the router to connect to other wireless devices that are also available for adhoc connections. Think of this mode as a Client Mode that doesn't connect to infrastructure networks but rather connects to other adhoc-configured devices. (Think of an adhoc network as a bunch of 8 year-olds without any adult supervision. Adhoc networks lack the central management that is typical of an infrastructure type network.) Adhoc mode doesn't use WDS but it does make use of STP.

Afterburner

Afterburner is also known as SpeedBooster, SuperSpeed, TurboG, 125mbps, HSP125, and G+. Your router (such as a WRT54G) may not have come stock with the feature in the firmware, but DD-WRT firmware enables this feature. Be aware that it is intended to speed up wireless throughput, but in certain circumstances it may slow down your throughput.

See Also: Afterburner

AP

(Access Point)
Access Point is the default and probably the most common mode. The Access Point mode allows wireless clients to access the Internet, access each other wirelessly, or access other computers that may be connected to the switch with wires. A router in Access Point mode cannot connect wirelessly to other routers, but it can have other routers connected to it wirelessly as clients or repeaters. Access Point is the mode used when configuring a router to act as a repeater.

B

Boot Wait

Boot Wait is a feature you will hopefully never need. It introduces a short delay while booting (5 seconds). During this delay, you can initiate the download of a new firmware image if the one in the flash ROM is not broken. Obviously, this is only necessary if the installed firmware will not boot. The default and recommended setting is "Enable". You can access the Boot Wait setting by going to "Administration" > "Management".

BGP

(Border Gateway Protocol)
BGP, the core routing protocol of the Internet, is generally used by Internet Service Providers to establish routing between one another. It is also used on private networks to "multihome". Do not use BGP unless you are sure that you need it.

Brick

1. improperly flashing one's WRT54G(S) in a way that renders it unusable
2. To cause to resemble a brick, in mode of operation as well as form
3. To render inert like a rock, or a brick, or... well you get the general idea

See Also: Recover from a Bad Flash

C

Captive Portal

(This entry needs your help.)

Chillispot

Chillispot can be used for hotspot management. It requires a separate webserver to host the redirect url and a separate radius server (these may be installed on the same machine, of course).

You can also use a hosted chillispot portal like http://worldspot.net which is free. It replaces both your radius server and your web server, and brings powerful features. You simply register there and create your hotspot. Then you can get the chillispot configuration settings to enter in the steps below, and you can get your hotspot working in some minutes. Visit http://www.dd-wrt.com/wiki/index.php/Chillispot

Client

(This entry needs your help.)

Client Bridge Mode

Client Bridge mode is much like Client mode except the WLAN and the LAN are on the same subnet. Consequently, NAT is no longer used and services (such as DHCP) that are running on the original network will work seamlessly on the bridged network. Just like Client mode, a router in Client Bridge mode will not accept wireless clients and it will not broadcast beacons. (Note: A technical problem exists in Client Bridge mode. It appears that this mode is not a fully transparent bridge mode as MAC addresses that pass through the Client Bridged router from behind the Client Bridged router, get rewritten to the MAC address of the Client Bridged router. (Sorry, I couldn't think of a more confusing way to write it.) If you really need transparent bridging, consider using WDS Bridging instead.)

See Also: Wireless Bridge

Client Mode

Client mode allows the router to connect to other access points as a client. In a nutshell, this turns the WLAN portion of your router into the WAN. In this mode, the router will no longer function as an Access Point (doesn't allow clients), therefore, you will need wires to use the router and to configure it. The router won't even be visible to your wireless configuration software or Wi-Fi sniffer software such as Netstumbler, since it no longer broadcasts beacons. In Client mode, the WLAN and the LAN will not be bridged, thus they will be on two different subnets. Port forwarding (from the WLAN to the LAN) will be necessary to make FTP servers, VNC servers, etc. that are located behind the Client mode router function properly. For this reason, most users chose to use Client Bridge mode instead of Client mode.

See Also: Client Mode Wireless

Cron

Normally called crontab, the cron subsystem is a type of scheduler for Unix/Linux that runs given commands at designated times. The default and the recommended setting is "enabled" since processes such as "Watchdog Scheduler" depend on it. You can access the Cron setting at "Administration" > "Management".

D

Daemon

In Unix/Linux, a daemon is a background process. Typically daemons have names that end with the letter "d"; for example, syslogd is the daemon which handles the system log.

DHCP

(Dynamic Host Control Protocol)
DHCP is a set of rules used by a communications device (such as a computer, router or networking adapter) to allow client devices to request and obtain an Internet address from a server which has a list of addresses available for assignment. DHCP is also used to pass on DNS Server and Gateway information to DHCP clients. WRT devices generally include DHCP servers in their software suite.

DMZ

(Demilitarized Zone)
A DMZ host is generally one selected device or computer on the network where all incoming traffic without a designated destination defined by PAT or Port forwarding, is forwarded to. Using a DMZ host is a lot like turning off the firewall capabilities inside your router and letting the DMZ host device handle all uninvited incoming traffic. For this reason, having a computer as a designated DMZ host can be a security hazard. DMZ is disabled by default in DD-WRT firmware. You can change DMZ settings by going to "Applications & Gaming" > "DMZ".

Domain Name

(This entry needs your help.)

DNS

(Domain Name System)

DNS Forwarder

Will forward any dns request, to a dns server of your choice (i.e. you isp's) usefull, for configuration/speed issues.

DNS Server

DNS Servers are the servers responsible for resolving names to IP addresses. When you point your browser to yahoo.com, a DNS Server has to resolve yahoo.com, (that is, look up the corresponding IP address) before the page is actually retrieved, since computers and networking equipment communicate using IP addresses instead of Domain Names. DNS Servers are built into routers, but they are only a local cacheing server that works in tandem with your LAN's DNS server(s) and/or your ISP's DNS servers.

DNSmasq

(This entry needs your help.)

Dynamic DNS

Dynamic DNS is a service that is hosted by a third party company. In order to take advantage of this service, devices (such as routers or computers) will require a client "updater" software to be installed to pass authentication and account information, and the network's current Internet IP address, in a timed manner. Many users want to be able to connect to another network (such as their home or office network) from another location but aren't able to connect unless they know the Internet IP address of that network. Because most ISP's provide IP addresses through DHCP (or charge extra for a static IP address) your IP address may change on occasion. Dynamic DNS is a system that allows you to match a domain name to your network's Internet IP address. Your Dynamic DNS updater software client will take care of passing the correct Internet IP address to centralized DNS servers on the Internet and will make sure it stays updated. So next time you want to connect to that network using VPN or Remote Access software you'll be able to use a domain name instead of trying to remember the IP address. Dynamic DNS services (such as www.dyndns.com) will help you choose from a list of available domain names.

Here's a list of Dynamic DNS service providers:

http://www.dyndns.com
http://www.easydns.com
http://freedns.afraid.org
http://www.no-ip.com
http://www.tzo.com
http://www.zoneedit.com

E

ESSID

Sometimes called SSID. It's the tag broadcast by your access point and the one seen on site survey at the clients. It's what you have to associate with. As a rule you can only have one ESSID per Access Point, however it would be cool to have more than one, it would then look like you had several Access Points.

See Also: v24

F

Firewall

Software or hardware that limits network activity

Firmware

This is just Software but it runs on your Hardware. It's usually delivered as a binary ROM image that has to be copied down onto your hardware (wrt54g) over a cable. The cable is usually an ethernet patch lead but could be a JTAG serial cable or doe some devices an RS232 cable. In the good old days we would burn an EPROM or FLASH chip in a programmer and then insert the chip phyically into a socket. Hence the term Firmware being software you can touch in the form of a chip.

G

Gateway

Setting the operating mode to "Gateway" allows your router to route packets between the LAN/WLAN and the Internet (through the WAN port). This is the default setting and the most common setting when the router is hosting the network's Internet connection through the WAN port

H

Host

Host is a generic term used when referring to a computer or device that is hosting a specific service or acting as some type of server. For example, if you have a mesh network in place, the "host" router would probably be the one hosting the Internet connection

Host Name

(This entry needs your help.)

Hotspot

A location where Wireless Internet has been provided for people to use. An example of this would be to switch on your laptop in a cafe and associate with the ESSID available there, perhaps CAFE-HOTSPOT. Attempting to view a website would show the HotSpot landing page where you could press a button for free access or create an account and pay by card. This depends on the operator of the HotSpot. Once in, you can simply use the Internet normally

HTTP Redirect

This option enables an HTTP Redirector for proxy usage See: HTTPRedirect

Hotzone

A large Hotspot, perhaps covering a whole town

I

Interface

a network adapter

See Also: http://wiki.openwrt.org/OpenWrtDocs/NetworkInterfaces

IPv6

(Internet Protocol Version 6)

ISP

Internet Service Provider

J

JFFS2

Journalling Flash File System (version 2)

JTAG

A JTAG cable is a a cable that hooks up to a JTAG interface, such as those on Linksys routers. It allows you to communicate with the router using your computer's parallel port. In many cases, a JTAG cable is an invaluable component used to debrick a partially or completely bricked (but not dead) router.

K

Kaid

The Kai console Daemon (kaid) is a service that provides tunneling for console games that do not have an inherent connection to the Internet. Although the label refers to XBOX, the daemon works well with PS2, and Gamecube consoles as well. It also allows the new Sony Playstation Portable (PSP) to go online with some of their multiplayer wireless games.

Kismet

Kismet is a layer 2 wireless network detector, sniffer, and intrusion detection software that runs on Linux.

See Also: Kismet Server/Drone

L

LAN

(Local Area Network) Local Area Network, or LAN, is your router's switch ports and your router's wireless interface have been bridged into one LAN. Most references in the forums and the Wiki are using the term LAN in this manner, although you may need to adjust your thinking according to the context it's used it. For example, the LAN on a WRT in Client mode is only the wired switch ports, because the wireless portion is acting a WAN interface.

Loopback

Loopback is a problem that occurs when multiple routes exist to the same destination. This can happen when a router is conncected to an adhoc network or is configured to function in a mesh network with several WDS-enabled routers. See STP

M

MAC Address

Media Access Control
A MAC address is a unique identifier attached to a network interface. It is stored in hexadecimal and usually appears in the following format: 00:00:00:00:00:00 or 00-00-00-00-00-00

MAC Filtering

A method of filtering which devices can or cannot connect to a WRT by storing corresponding MAC addresses. MAC filtering is generally only performed on the wireless interface of a WRT.

=MAC Number

Migration Authorisation Code number. Not to be confused with MAC Address. This is the number your ADSL ISP gives you when you want to switch to another ISP without a long wait whilst the phone company sends out engineers to move the wires. As you can imagine, this number can be held to ransom until you pay the old ISP bill, which is ofcourse a contravention of the Ofcom guidelines

Mesh Network

(This entry needs your help.)

N

NAT

(Network Address Translation)

Neutered

In the world of DD-WRT and Linksys routers, a neutered router is a v5 or v6 router that has reduced RAM and reduced flash memory, in comparison to other supported devices, thus the name neutered.

NoCat

(This entry needs your help.)

nvram

The nvram is a portion of your router called Non-Volatile RAM. Your configuration/settings are stored in the nvram.

O

OpenVPN

(This entry needs your help.)

OSPF

(Open Shortest Path First) one of several router protocols known as IGP's, (Interior Gateway Protocol). Using OSPF, a host that obtains a change to a routing table or detects a change in the network will immediately multicast the information to all other hosts in the network so that all will have the same routing table information. This method is more efficient than RIP (Routing Information Protocol) which sends the entire routing table to a neighboring host every 30 seconds. OSPF also uses more advanced algorithms to determine the shortest path, where RIP1 and RIP2 simply use hop counts. If your router is acting as a repeater, OSPF is the recommended protocol to use unless your network has other devices that only support RIP2.

P

Port Forwarding

Port Forwarding is necessary to allow computers outside of the LAN to access services that may be hosted by one or more computers inside the LAN. Since there is a shortage of public IP addresses in IPv4, the issue was conquered using NAT. While NAT isn't all bad (it adds security) it does introduce some complications when a computer inside an LAN is hosting a public service such as a web server, ftp server, or e-mail server. Port forwarding was designed to take care of this problem. Port forwarding can be configured in DD-WRT by going to "Applications & Gaming" > "Port Forwarding". You can also forward ranges of ports instead of single ports by going to "Applications & Gaming" > "Port Range Forwarding". Routers can be configured to listen on one port but forward to a different port. While it isn't foolproof, this can add a measure of security by using obscure ports to listen instead of the default ports that attackers expect you to host common services on.

Port Triggering

(This entry needs your help.)

PPPoE

(Point-to-Point Protocol over Ethernet)

PPTP

(Point-to-Point Tunneling Protocol)

Q

QoS

(Quality of Service)
See Also: Quality of Service

R

RADVD

(This entry needs your help.)

Repeater

While repeater is not a selection in the "Wireless Mode" drop-down menu, it is commonly thought of as a mode that is different from the others listed above. In reality, a router acting as a repeater is configured as an Access Point (AP Mode) and has WDS (Wireless Distribution System) enabled. To use your router as a repeater will also require you to enable and configure WDS in the router you are connecting to (the "host router"). Do not attempt to turn on repeater mode by using the "Site Survey" and then the "Join" button to connect to other routers, as this will actually put your router into Client mode. Also, be aware that using your router as a repeater will reduce the router's wireless throughput since WDS uses wireless bandwidth that would normally be available to wireless clients, to "talk" to other routers. This reduction in wireless bandwidth will probably not be noticeable if the repeater router(s) are used only to share an Internet connection, unless you have more than three routers "daisy-chained" in this manner.

See Also: WDS Linked router network

RIP

(Routing Information Protocol )
RIP1 and RIP2 are both older protocols that are to be used only when an existing network does not have OSPF compliant equipment. In short, RIP2 is slightly more secure and slightly more efficient than RIP1, while OSPF has great advantages over both. It is assumed that RIP2 is in the feature set primarily for backwards compatibility reasons.

RFlow

(This entry needs your help.)

Router

See: WRT

Rx

receive

S

Samba

Linix implentation, of the wide known windows file sharing system

SNMP

(This entry needs your help.)

Source Code

This is the software before cross compliation into Firmware. For Firmware this is usually written in 'C'. For dd-wrt the source can be downloaded and cross compiled on the PC to produce firmware which is ready to be downloaded onto the wrt54g. This is not something most people need to do since the binary firmware is provided for download from the site

SSH

(Secure Shell)
SSH clients can access information and make changes to remote systems that are running an SSH server. Telnet or SSH can be used as another method of changing settings on your DD-WRT router, as opposed to the Web Interface. Certain changes to your DD-WRT router can only be done using Telnet or SSH. More Info on using Telnet/SSH

STP

Spanning Tree Protocol
STP needs to be enabled to prevent loopbacks on networks where multiple paths to the same point are possible. A mesh network that uses multiple repeaters where repeaters have WDS configured to work with more than one device should enable STP. STP is known to interfere with the router's DHCP client for users who use Comcast Cable as their ISP.

For more information see: STP

T

Telnet

Telnet clients can access information and make changes to remote systems that are running a Telnet server. SSH is similar to Telnet and is preferred because Telnet traffic is not encrypted, thus usernames and passwords are passed in plain text and can easily be sniffed by packet sniffing software. Telnet or SSH can be used as another method of changing settings on your DD-WRT router, as opposed to the Web Interface. Certain changes to your DD-WRT router can only be done using Telnet or SSH. More Info on using Telnet/SSH

Tx

transmit

U

UPnP

(Universal Plug-N-Play)

V

VLAN

(Virtual Local Area Network)
A VLAN is, in basic terms, a group of physical interfaces on a switch that behave as if they are a separate standalone switch. While using one physical switch, a VLAN allows you to partition it into multiple LANs, each one completely isolated from the others. The switch must support VLAN configurations - most cheap switches don't allow this, but high end manageable switches do, as does the internal switch on DD-WRT compatible routers.

VoIP

Voice over Internet Protocol VoIP is a rather new technology for making phonecalls using the Internet. Skype is an example of VoIP but so is Vonage which allows you to use a real phone directly plugged into your wrt54g rather than needing to fire up your PC.

VPN

Virtual Private Network A VPN allows two LANs together over the Internet using a virtual cable, or VPN. You have PPTP, IPSec, OpenVPN. Mostly dd-wrt is not too good at doing this but will allow these service to operate as a pass-through. Hence the term VPN-Passthrough.

VPN Passthough

The router allows you to run a VPN service on your network. Not particularly amazing. The VPN version of dd-wrt has this.

VPN Server

This is where the router actually creates a VPN connection to another VPN server. This is the one you really want for VPN. The VPN version of dd-wrt does not seem to do this.

W

WAN

(Wide Area Network)

WDS

(Wireless Distribution System)
A Wireless Distribution System is a system that enables the interconnection of access points wirelessly. In DD-WRT, WDS allows multiple WRT's to communicate with each other wirelessly without the need for a wired backbone. A WRT communicating in this manner is generally referred to as a repeater.

WDS Bridging

WDS Bridging is when you setup a repeater router to to "talk" to a main/host router and then disable the Access Point function in the repeater so that it will not accept clients. You'll need to run a short script from the shell to achieve this. A WDS Bridge is fully transparent. In this configuration the wireless portion of the repeater WRT has bridged the repeater WRT's LAN interface with another WDS enabled wireless device. WDS Bridging is done in Access Point mode.

See Also: WDS Bridging

WISP

Wireless Internet Service Provider. A company using wireless gear such as WRT54G and dd-wrt to deliver Broadband Internet into peoples homes without using their phone line. The advantage of a WISP is that you are not limited by the speed of your telephone line and perhaps you don't even have a telephone line. Since there is no telephone line, the WISP is not paying huge fees to the phone company, so can often provide a better service for the same money. You could start your own WISP or at least a HotSpot with your dd-wrt.

WLAN

(Wireless Local Area Network)

WOL

(Wake-On-LAN)
Wake-on-LAN is an Ethernet computer networking standard that allows a shut-down computer to be booted remotely. The network card of the computer that has WOL enabled will listen for a "Magic Packet", then verify the information in that packet and decide whether or not to boot the computer.

Wombling

Also known as War Driving. The act of scanning for Wireless networks an HotSpots whilst traveling. This was traditionally done with a Proxim ORiNOCO PCMCIA card in a laptop with a Pringles Tube Yagi antenna. We are talking old school. The connection with the Wombles comes from 'Orinoco' who is ofcourse one of the Wombles from Wimbledon Common. It is often thought that using someones Internet is illegal. It seems to be a form of trespass, so if you don't look at any local files or break anything then you're probably OK. However if you bring their connection into disrepute or slow it down significantly or look at their personal files then you are clearly a bandit and could get prosecuted. If they have taken trouble to secure the connection then you should respect that and not break past the security.

WRT

(Wireless Receiver/Transceiver)

X

Y

Z