Knot

DNS, Knot
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KNOT DNS

some information related to knot dns / knot-dnsutils. Tested with ‘knotd (Knot DNS), version 3.3.3’ running on OpenBSD 7.5.

Install Knot

pkg_add knot

Build Config

we’re configure this server as “slave” which get’s it’s config from a Primary Nameserver

# /etc/knot/knot.conf 

server:
    rundir: "/var/run/knot"
    user: _knot:_knot
    automatic-acl: on
    listen: [ xx.xx.xx.xx@53, xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx@53 ]

log:
  - target: syslog
    any: info

database:
    storage: "/var/db/knot"

key:
  - id: mykey
    algorithm: hmac-sha256
    secret: xXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXx=

remote:
  - id: primary
    address: [ xx.xx.xx.xx@53, xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx@53 ] # IP Address of Primary Nameserver
    key: mykey

template:
  # default
  - id: default
    storage: "/var/db/knot"
    file: "%s.zone"
    global-module: mod-stats
    semantic-checks: on

zone:

  # Slave Zones
  - domain: your-domain.ch
    master: primary
  - domain: your-other-domain.de
    master: primary
  - domain: your-last-domain.com
    master: primary

enable and start service

rcctl enable knot
rcctl restart knot

zone backup

folder="/tmp/knot"
mkdir $folder
chown -R _knot $folder
knotc zone-backup +backupdir $folder

Build query File

cat ${folder}/zonefiles/stoege.net.zone |awk "{print \$1,\$3}" |grep -E "(NS|DS|A|AAAA|PTR|MX|SOA)$" |\
  sort -u -R > ${folder}/queries.txt

StressTests (from a Debian Box)

apt install knot-dnsutils
cd /tmp
scp root@45.32.159.233:/tmp/knot/queries.txt .

5k Queries

kxdpgun -i queries.txt 45.32.159.233

using interface ens18, XDP threads 1, UDP, native mode
thread#00: sent 5010, received 5010
total queries:     5010 (1002 pps)
total replies:     5010 (1002 pps) (100%)
average DNS reply size: 63 B
average Ethernet reply rate: 842459 bps (0.84 Mbps)
responded NOERROR:   5010
duration: 5 s

100k Queries

time kxdpgun -t 20 -Q 5000 -i queries.txt -b 20 -p 8853 45.32.159.233

using interface ens18, XDP threads 1, UDP, native mode
thread#00: sent 100020, received 0
total queries:     100020 (5001 pps)
total replies:     0 (0 pps) (0%)
average DNS reply size: 0 B
average Ethernet reply rate: 24 bps (0.00 Mbps)
duration: 20 s

real	0m22.052s
user	0m0.092s
sys	0m0.183s

khost – Simple DNS lookup utility¶

# khost stoege.net
stoege.net. has IPv4 address 159.69.214.12
stoege.net. has IPv6 address 2a01:4f8:c0c:fff7::2
stoege.net. mail is handled by 10 ideo.noflow.ch.

# khost stoege.net -t SOA
stoege.net. start of authority is ns1.noflow.ch. hostmaster.noflow.ch. 2024052701 3600 900 1209600 1800

kdig – Advanced DNS lookup utility¶

# kdig stoege.net A    
;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 57426
;; Flags: qr rd ra; QUERY: 1; ANSWER: 1; AUTHORITY: 0; ADDITIONAL: 0

;; QUESTION SECTION:
;; stoege.net.         		IN	A

;; ANSWER SECTION:
stoege.net.         	1800	IN	A	159.69.214.12

;; Received 44 B
;; Time 2024-07-10 19:27:20 CEST
;; From 108.61.10.10@53(UDP) in 1.4 ms

short answer

# kdig +short stoege.net AAAA
2a01:4f8:c0c:fff7::2

output in json

# kdig +json stoege.net AAAA
{
  "dateString": "2024-07-10T19:28:01+0200",
  "dateSeconds": 1720632481,
  "msgLength": 56,
  "ID": 27609,
  "QR": 1,
  "Opcode": 0,
  "AA": 0,
  "TC": 0,
  "RD": 1,
  "RA": 1,
  "AD": 0,
  "CD": 0,
  "RCODE": 0,
  "QDCOUNT": 1,
  "ANCOUNT": 1,
  "NSCOUNT": 0,
  "ARCOUNT": 0,
  "QNAME": "stoege.net.",
  "QTYPE": 28,
  "QTYPEname": "AAAA",
  "QCLASS": 1,
  "QCLASSname": "IN",
  "answerRRs": [
    {
      "NAME": "stoege.net.",
      "TYPE": 28,
      "TYPEname": "AAAA",
      "CLASS": 1,
      "CLASSname": "IN",
      "TTL": 1800,
      "rdataAAAA": "2a01:4f8:c0c:fff7::2",
      "RDLENGTH": 16,
      "RDATAHEX": "2A0104F80C0CFFF70000000000000002"
    }
  ]
}
Any Comments ?

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