Need basic understand the Traffic flow between Cisco ISE <--> SMTP

[ricky.kocharekar@orange.com]

Need a basic understanding of the Traffic flow between Cisco ISE <-> SMTP.

[Rob Ingram]

ricky.kocharekar@orange.com refer to this guide, which lists which nodes communicate using SMTP and for what function/service.

https://www.cisco.com/c/en/us/td/docs/security/ise/2-7/InstallGuide27/b_ise_InstallationGuide27/b_ise_InstallationGuide27_chapter_0110.html

On ISE you could run tcpdump to take a packet capture - filter on tcp/25 or smtp server IP address and generate traffic - this will confirm the traffic flow.

[balaji.bandi]

We are not sure what is the context here, ISE uses SMTP (or SMTP relay to send emails) depending on setup, it uses Port 25 by default. (if you looking SMTP Flow, it just like any other client who try to access SMTP EHLO--250---bla--bla---quit ---221)

if you looking for config check below :

https://www.cisco.com/c/en/us/support/docs/security/identity-services-engine/216187-configure-secure-smtp-server-on-ise.html

[thomas]

This would be the authority on SMTP: https://www.rfc-editor.org/rfc/rfc5321.html