Introducción
Este documento describe cómo utilizar dig/nslookup
para buscar registros SPF, DKIM y DMARC de un dominio en Email Security Appliance (ESA) y Cloud Email Security (CES).
Prerequisites
Requirements
Cisco recomienda que tenga conocimiento sobre estos temas:
- ESA en Async OS 10.0 o posterior
- Acceso administrativo al dispositivo
Componentes Utilizados
La información de este documento se basa en todos los modelos de hardware ESA y dispositivos virtuales compatibles en Async OS 10.0 o posterior.
Para verificar la información de versión del dispositivo desde la CLI, ingrese el comando version. En la GUI, vaya a Monitor > System Status
.
Ambas nslookup
y dig
Los comandos se soportan en las versiones actuales de ESA/CES Async OS. Estos comandos se pueden ejecutar mediante el acceso SSH/CLI al dispositivo.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. Si tiene una red en vivo, asegúrese de entender el posible impacto de cualquier comando.
Las salidas de ejemplo proporcionadas son para dominios cisco.com
y gmail.com
, también se pueden utilizar comandos similares para otros dominios.
SPF
Las búsquedas SPF se pueden realizar con estos formatos:
nslookup
dominio txt
dig
dominio txt
Nota: Ssustituir la palabra domain
con el dominio adecuado que desea buscar.
Para dominios con varios registros TXT publicados, nslookup
puede fallar al enumerar los registros SPF. En tales casos, dig
en su lugar.
Esto se muestra en los resultados de ejemplo aquí para cisco.com
.
(Machine lab.esa.com)> nslookup cisco.com txt
TXT="google-site-verification=qPS9ZkoQ-Og1rBrM1_N7z-tNJNy2BVxE8lw6SB2iFdk"
TTL=21m 8s
(Machine lab.esa.com)> dig cisco.com txt
;; Warning: Message parser reports malformed message packet.
;; Truncated, retrying in TCP mode.
; <<>> DiG 9.11.2 <<>> cisco.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20648
;; flags: qr rd ra; QUERY: 1, ANSWER: 25, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;cisco.com. IN TXT
;; ANSWER SECTION:
cisco.com. 1782 IN TXT "fastly-domain-delegation-w049tcm0w48ds-341317-20210209"
cisco.com. 1782 IN TXT "v=spf1 redirect=spfa._spf.cisco.com"
cisco.com. 1782 IN TXT "MS=ms35724259"
cisco.com. 1782 IN TXT "amazonses:QbUv5pPHGQxRy1vKA0J7Y/biE9oR6MTxOTI1bZIfjsw="
cisco.com. 1782 IN TXT "fastly-domain-delegation-e9a758d22183504af2d5ab4d9a9853da-20210127"
cisco.com. 1782 IN TXT "QuoVadis=94d4ae74-ecd5-4a33-975e-a0d7f546c801"
cisco.com. 1782 IN TXT "atlassian-domain-verification=672RcADvt8BPqsb9gCN2ZC5DoTAhUT8abC1blYKQxi/MHMaGoA/BuvjFMaWRtgd7"
cisco.com. 1782 IN TXT "google-site-verification=9MlQU9MMQ1jHLMUkONKe6QzZ-ZIGRv0BCD1_rY1Zdmc"
cisco.com. 1782 IN TXT "SFMC-o7HX74BQ79k7glpt_qjlF2vmZO9DpqLtYxKLwg87"
cisco.com. 1782 IN TXT "926723159-3188410"
cisco.com. 1782 IN TXT "docusign=95052c5f-a421-4594-9227-02ad2d86dfbe"
cisco.com. 1782 IN TXT "amazonses:7LyiKZmpuGja4+KbA4xX3lN69yajYKLkHH4QJcWnuwo="
cisco.com. 1782 IN TXT "google-site-verification=qPS9ZkoQ-Og1rBrM1_N7z-tNJNy2BVxE8lw6SB2iFdk"
cisco.com. 1782 IN TXT "zpSH7Ye/seyY61hH8+Rq5Kb+ZJ9hDa+qeFBaD/6sPAAg+2POkGdP0byHb1pFVK9uZgYF2AIosUSZq4MB17oydQ=="
cisco.com. 1782 IN TXT "duo_sso_verification=AxenLdoqIXzjl2RJzE1BlOfkawDbDFlnbyvjAt8vcjKHBkvYwEMySDRk5QmBd66v"
cisco.com. 1782 IN TXT "facebook-domain-verification=1zoxo8z7t013gpruxmhc8dkerq47vh"
cisco.com. 1782 IN TXT "google-site-verification=lW5eqPMJI4VrLc28YW-JBkqA-FDNVnhFCXQVDvFqZTo"
cisco.com. 1782 IN TXT "facebook-domain-verification=qr2nigspzrpa96j1nd9criovuuwino"
cisco.com. 1782 IN TXT "apple-domain-verification=qOInipPgso3W8cmK"
cisco.com. 1782 IN TXT "identrust_validate=JnSSfW+y58dEQju6mVBe8lu1MGFepXI50P27OE1ZZQmL"
cisco.com. 1782 IN TXT "onetrust-domain-verification=20345dd0c33946f299f14c1498b41f67"
cisco.com. 1782 IN TXT "mixpanel-domain-verify=2c6cb1aa-a3fb-44b9-ad10-d6b744109963"
cisco.com. 1782 IN TXT "identrust_validate=Wns4/AOM0Ij2kQCQhzvNbMcoBzxItOa+44O7KF06lIp3"
cisco.com. 1782 IN TXT "docusign=5e18de8e-36d0-4a8e-8e88-b7803423fa2f"
cisco.com. 1782 IN TXT "amazonses:mX+ylQj+fJAfh9pr03yIR7YvjKZ1bOo5ABegqM/5pvI="
;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Feb 23 06:03:28 GMT 2021
;; MSG SIZE rcvd: 1756
(Machine lab.esa.com)> nslookup gmail.com txt
TXT="v=spf1 redirect=_spf.google.com"
TTL=30m
(Machine lab.esa.com)> dig gmail.com txt
; <<>> DiG 9.11.2 <<>> gmail.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14807
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;gmail.com. IN TXT
;; ANSWER SECTION:
gmail.com. 1800 IN TXT "v=spf1 redirect=_spf.google.com"
gmail.com. 1800 IN TXT "globalsign-smime-dv=CDYX+XFHUw2wml6/Gb8+59BsH31KzUr6c1l2BPvqKX8="
;; Query time: 85 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Feb 23 06:05:38 GMT 2021
;; MSG SIZE rcvd: 148
DKIM
Las búsquedas DKIM se pueden realizar con estos formatos:
nslookup
selector._domainkey.domain.txt
dig
selector._domainkey.domain.txt
Nota: Sustituir las palabras selector
y domain
con el selector DKIM y el dominio que desea buscar.
(Machine lab.esa.com)> nslookup iport._domainkey.cisco.com txt
TXT="v=DKIM1;
p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCctxGhJnvNpdcQLJM6a/0otvdpzFIJuo73OYFuw6/8bXcf8/p5JG/iME1r9fUlrNZs3kMn9ZdPYvTyRbyZ0UyMrsM3ZN2JAIop3M7sitqHgp8pbORFgQyZxq+L23I2cELq+qw
tbanjWJzEPpVvrvbuz9QL8CUtS+V5N5ldq8L/lwIDAQAB;"
TTL=1d
(Machine lab.esa.com)> dig iport._domainkey.cisco.com txt
; <<>> DiG 9.11.2 <<>> iport._domainkey.cisco.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21671
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;iport._domainkey.cisco.com. IN TXT
;; ANSWER SECTION:
iport._domainkey.cisco.com. 86400 IN TXT "v=DKIM1;
p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCctxGhJnvNpdcQLJM6a/0otvdpzFIJuo73OYFuw6/8bXcf8/p5JG/iME1r9fUlrNZs3kMn9ZdPYvTyRbyZ0UyMrsM3ZN2JAIop3M7sitqHgp8pbORFgQyZxq+L23I2cELq+qw
tbanjWJzEPpVvrvbuz9QL8CUtS+V5N5ldq8L/lwIDAQAB;"
;; Query time: 2 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Feb 23 06:41:31 GMT 2021
;; MSG SIZE rcvd: 285
(Machine lab.esa.com)> dig 20161025._domainkey.gmail.com TXT
; <<>> DiG 9.11.2 <<>> 20161025._domainkey.gmail.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11798
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;20161025._domainkey.gmail.com. IN TXT
;; ANSWER SECTION:
20161025._domainkey.gmail.com. 1800 IN TXT "k=rsa;
p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAviPGBk4ZB64UfSqWyAicdR7lodhytae+EYRQVtKDhM+1mXjEqRtP/pDT3sBhazkmA48n2k5NJUyMEoO8nc2r6sUA+/Dom5jRBZp6qDKJOwjJ5R/OpHamlRG+YRJQqR"
"tqEgSiJWG7h7efGYWmh4URhFM9k9+rmG/CwCgwx7Et+c8OMlngaLl04/bPmfpjdEyLWyNimk761CX6KymzYiRDNz1MOJOJ7OzFaS4PFbVLn0m5mf0HVNtBpPwWuCNvaFVflUYxEyblbB6h/oWOPGbzoSgtRA47SHV53SwZjIsVpb
q4LxUW9IxAEwYzGcSgZ4n5Q8X8TndowsDUzoccPFGhdwIDAQAB"
;; Query time: 174 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Feb 23 06:45:01 GMT 2021
;; MSG SIZE rcvd: 462
(Machine lab.esa.com)> nslookup 20161025._domainkey.gmail.com TXT
TXT="k=rsa;
p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAviPGBk4ZB64UfSqWyAicdR7lodhytae+EYRQVtKDhM+1mXjEqRtP/pDT3sBhazkmA48n2k5NJUyMEoO8nc2r6sUA+/Dom5jRBZp6qDKJOwjJ5R/OpHamlRG+YRJQqR"
"tqEgSiJWG7h7efGYWmh4URhFM9k9+rmG/CwCgwx7Et+c8OMlngaLl04/bPmfpjdEyLWyNimk761CX6KymzYiRDNz1MOJOJ7OzFaS4PFbVLn0m5mf0HVNtBpPwWuCNvaFVflUYxEyblbB6h/oWOPGbzoSgtRA47SHV53SwZjIsVpb
q4LxUW9IxAEwYzGcSgZ4n5Q8X8TndowsDUzoccPFGhdwIDAQAB"
TTL=30m
DMARC
Las búsquedas de DMARC se pueden realizar con estos formatos:
nslookup
_dmarc.domain txt
dig
_dmarc.domain txt
Nota: Ssustituir la palabra domain
con el dominio que desea buscar.
(Machine lab.esa.com)> nslookup _dmarc.cisco.com txt
TXT="v=DMARC1; p=quarantine; pct=0; fo=1; ri=3600; rua=mailto:cisco@rua.agari.com; ruf=mailto:cisco@ruf.agari.com"
TTL=30m
(Machine lab.esa.com)> dig txt _dmarc.cisco.com
; <<>> DiG 9.11.2 <<>> _dmarc.cisco.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24522
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;_dmarc.cisco.com. IN TXT
;; ANSWER SECTION:
_dmarc.cisco.com. 1800 IN TXT "v=DMARC1; p=quarantine; pct=0; fo=1; ri=3600; rua=mailto:cisco@rua.agari.com; ruf=mailto:cisco@ruf.agari.com"
;; Query time: 2 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Feb 23 06:34:15 GMT 2021
;; MSG SIZE rcvd: 155
(Machine lab.esa.com)> nslookup _dmarc.gmail.com txt
TXT="v=DMARC1; p=none; sp=quarantine; rua=mailto:mailauth-reports@google.com"
TTL=30m
(Machine lab.esa.com)> dig _dmarc.gmail.com txt
; <<>> DiG 9.11.2 <<>> _dmarc.gmail.com TXT
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28370
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; QUESTION SECTION:
;_dmarc.gmail.com. IN TXT
;; ANSWER SECTION:
_dmarc.gmail.com. 1800 IN TXT "v=DMARC1; p=none; sp=quarantine; rua=mailto:mailauth-reports@google.com"
;; Query time: 85 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Tue Feb 23 06:35:18 GMT 2021
;; MSG SIZE rcvd: 118
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