Wednesday, March 20, 2013

Block Outbound Port 25 SMTP Traffic Cisco Catalyst Switch ACL

Log into to your switch, enter "enable" mode, then "configure terminal" mode:
access-list 199 deny tcp any any eq smtp
access-list 199 permit ip any any
Now, on any interface that you want to deny outbound port 25 SMTP traffic to:
ip access-group 199 in
Write out the changes and you're done