A DNSWL ("
DNS
The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ...
-based
whitelist
A whitelist, allowlist, or passlist is a mechanism which explicitly allows some identified entities to access a particular privilege, service, mobility, or recognition i.e. it is a list of things allowed when everything is denied by default. It is ...
") is a "whitelist" of semi-trusted locations on the Internet. The locations consist of
IP address
An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...
es which may be reputed with no or low occurrences of
spamming
Spamming is the use of messaging systems to send multiple unsolicited messages (spam) to large numbers of recipients for the purpose of commercial advertising, for the purpose of non-commercial proselytizing, for any prohibited purpose (especial ...
.
Generic need for whitelisting
Natural language understanding
Natural-language understanding (NLU) or natural-language interpretation (NLI) is a subtopic of natural-language processing in artificial intelligence that deals with machine reading comprehension. Natural-language understanding is considered an ...
is not a mature field. Common computer processes used for spam filtering apply
heuristics
A heuristic (; ), or heuristic technique, is any approach to problem solving or self-discovery that employs a practical method that is not guaranteed to be optimal, perfect, or rational, but is nevertheless sufficient for reaching an immediate, ...
to avoid presenting too many useless messages to email recipients. This has the severe impact of reducing SMTP reliability
[See ]Bounce message
A bounce message or just "bounce" is an automated message from an email system, informing the sender of a previous message that the message has not been delivered (or some other delivery problem occurred). The original message is said to have "boun ...
for a discussion about delivery errors, and backscatter (e-mail)
Backscatter (also known as outscatter, misdirected bounces, blowback or collateral spam) is incorrectly automated bounce messages sent by mail servers, typically as a side effect of incoming spam.
Recipients of such messages see them as a form of ...
for why they cannot always be noticed to the sender. by creating
false positive
A false positive is an error in binary classification in which a test result incorrectly indicates the presence of a condition (such as a disease when the disease is not present), while a false negative is the opposite error, where the test result ...
s; i.e., silently dropping legitimate messages. Whitelists tackle the task of vouching for a sender, which implies identifying an accountable party that the sender belongs to.
DNS whitelisting can also be applied to web traffic when doing incident response or network forensics, since it helps the analyst to tell malicious domains apart from "normal" web surfing. It is, however, not recommended to actively block web traffic not on the whitelist, since this would cause even legit web surfing to be blocked.
For
IPv6
Internet Protocol version 6 (IPv6) is the most recent version of the Internet Protocol (IP), the communication protocol, communications protocol that provides an identification and location system for computers on networks and routes traffic ...
, blacklisting is not a realistic option, because of the greatly increased addresses. So whitelisting can be used to reduce a huge address space to a set of manageable size: first build a global whitelist of IPv6 registered senders, and second blacklist within that. By accepting all authentic sender registration request, it is at least possible to eliminate
spambot
A spambot is a computer program designed to assist in the sending of spam. Spambots usually create accounts and send spam messages with them. Web hosts and website operators have responded by banning spammers, leading to an ongoing struggle betw ...
s.
See also
*
Automated whitelist An automated whitelist is a whitelist which was created and/or is maintained by a system that analyzes bi-directional email.
Use by anti-spam systems
An automated whitelist is a whitelist which is created or maintained by a system that monitors i ...
*
Vouch by Reference
Vouch by Reference (VBR) is a protocol used in Internet mail systems for implementing sender certification by third-party entities. Independent certification providers vouch for the reputation of senders by verifying the domain name that is associa ...
*
DNSBL
A Domain Name System blocklist, Domain Name System-based blackhole list, Domain Name System blacklist (DNSBL) or real-time blackhole list (RBL) is a service for operation of mail servers to perform a check via a Domain Name System (DNS) query whe ...
black list
Notes
References
{{Spamming
Spamming
Spam filtering
Email authentication