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Kismet is a layer 2 wireless network detector, sniffer, and intrusion detection software that runs on Linux. Kismet is a layer 2 wireless network detector, sniffer, and intrusion detection software that runs on Linux.
-''See Also:'' [[Kismet Server/Drone|Kismet]]+''See Also:'' [[Kismet Server/Drone| Kismet]]
===LAN=== ===LAN===

Revision as of 02:22, 8 October 2006

This glossary is intended to give an overview of terms used in wireless networking, DD-WRT firmware, on the forum, and on the Wiki. The intention of the Wiki editors is to go beyond the generally brief definitions in glossarys and help the reader understand how the term or feature is used in DD-WRT. This list is not exhuastive or authoritative by any means. If you see something missing or incorrect, you're welcome to add it, edit it, or post a question on this glossary's discussion page.


802.1x Extensible Authentication Protocol (EAP)

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Access Restrictions

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In DD-WRT firmware, adhoc is a wireless mode that allows your router to function on an adhoc network.

See Also: Wireless Modes


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

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".


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

Captive Portal

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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.)

Client Mode

Client Mode allows the router to connect to other access points as a client. Normally the WLAN and the switch ports have been bridged into one LAN, but under Client mode, the Wireless portion of the WRT becomes your WAN and the switch ports are the LAN. Port forwarding is necessary between the Wireless WAN and the LAN, because the two interfaces are not bridged. Obviously, to use Client Mode, a computer/device will need to be plugged into the Client Mode router with a cable, since the router will not accept wireless clients. See Also: Wireless Modes


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".


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.


(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.


(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

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(Domain Name System)

DNS Forwarder

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DNS Server

DNS Servers are the servers responsible for resolving names to IP addresses. When you point your browser to, a DNS Server has to resolve, (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.


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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 will help you choose from a list of available domain names.

Here's a list of Dynamic DNS service providers:


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

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HTTP Redirect

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


a network adapter

See Also:


(Internet Protocol Version 6)


Internet Service Provider


Journalling Flash File System (version 2)


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.


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

See Also: Kismet


(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 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

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.

Mesh Network

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(Network Address Translation)


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.


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


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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

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(Point-to-Point Protocol over Ethernet)


(Point-to-Point Tunneling Protocol)


(Quality of Service)
For a basic How-To on using QoS, see Quality of Service.


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A repeater is a WRT that's wirelessly connected to a host router or other repeater routers in a mesh network. A WRT configured as a repeater uses Access Point mode with WDS enabled.

See Also: Wireless Modes


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See: WRT




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(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


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


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




(Universal Plug-N-Play)


(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.


(Wide Area Network )


(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

Quite simply stated, 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.


(Wireless Local Area Network)


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.


(Wireless Receiver/Transceiver)