DnAlias - Random DNAME Aliases

DnAlias - Random DNAME Aliases

This module is designed to return one or more random aliases using DNAME (Delegation Name) records.

It specifically generates a random DNAME alias record in the format dnalias######.yourdomain.com, where ###### represents a random number.

The idea is that if the client/resolver decides to resolve this further, it will result in the generation of yet another alias, theoretically leading to a resolution of infinite chain of random aliases. In practice, however, most modern resolvers will terminate the resolution after encountering several consecutive alias records.

Note that this feature provides the same functionality as requesting the DNAME record for the generic alias feature. Responding with multiple records (aliases) in a single response is also supported.

⚠BEWARE⚠This can potentially lead to amplification effect (DoS) or domain lock-up (DoS).

Category: Aliases

Tags: Amplification, Domain Lock-Up, Denial of Service

RFCs: RFC2672, RFC6672

Format 

dnalias.<NUMBER>.yourdomain.com

Where:

  • The <NUMBER> parameter defines how many aliases should be generated in the response.

Examples

By default, it returns a single DNAME alias:

# dig dnalias.yourdomain.com @127.0.0.1

; <<>> DiG 9.18.10-2-Debian <<>> dnalias.yourdomain.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28510
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;dnalias.yourdomain.com.		IN	A

;; ANSWER SECTION:
dnalias.yourdomain.com.	60	IN	DNAME	dnalias50911.yourdomain.com.

;; Query time: 4 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Wed Oct 16 09:37:09 +04 2024
;; MSG SIZE  rcvd: 81

Download PCAP File


Same example as above, but this time we explicitly specify that we want to receive a single DNAME record:

# dig dnalias.1.yourdomain.com @127.0.0.1

; <<>> DiG 9.18.10-2-Debian <<>> dnalias.1.yourdomain.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28666
;; flags: qr aa; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;dnalias.1.yourdomain.com.	IN	A

;; ANSWER SECTION:
dnalias.1.yourdomain.com. 60	IN	DNAME	dnalias176816.1.yourdomain.com.

;; Query time: 4 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Wed Oct 16 09:37:10 +04 2024
;; MSG SIZE  rcvd: 86

Download PCAP File


In this case, we specify that we want to receive five DNAME aliases:

# dig dnalias.5.yourdomain.com @127.0.0.1

; <<>> DiG 9.18.10-2-Debian <<>> dnalias.5.yourdomain.com @127.0.0.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41772
;; flags: qr aa; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;dnalias.5.yourdomain.com.	IN	A

;; ANSWER SECTION:
dnalias.5.yourdomain.com. 60	IN	DNAME	dnalias563699.5.yourdomain.com.
dnalias.5.yourdomain.com. 60	IN	DNAME	dnalias976992.5.yourdomain.com.
dnalias.5.yourdomain.com. 60	IN	DNAME	dnalias894931.5.yourdomain.com.
dnalias.5.yourdomain.com. 60	IN	DNAME	dnalias105.5.yourdomain.com.
dnalias.5.yourdomain.com. 60	IN	DNAME	dnalias127029.5.yourdomain.com.

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Wed Oct 16 09:37:11 +04 2024
;; MSG SIZE  rcvd: 259

Download PCAP File


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