Home » Networking » Security

What command will permit SMTP mail to only host 1.1.1.1?

Correct Answer: access-list 110 permit tcp any host 1.1.1.1 eq smtp

Explanation:

When trying to find the best answer to an access-list question, always check the access-list number and then the protocol. When filtering to an upper-layer protocol, you must use an extended list, numbers 100-199 and 2000-2699. Also, when you filter to an upper-layer protocol, you must use either tcp or udp in the protocol field. If it says ip in the protocol field, you cannot filter to an upper-layer protocol. SMTP uses TCP.

← Previous Question Next Question→

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion