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Networking - Security - Discussion

Discussion Forum : Security - Security (Q.No. 6)
Security
6.
What command will permit SMTP mail to only host 1.1.1.1?
access-list 10 permit smtp host 1.1.1.1
access-list 110 permit ip smtp host 1.1.1.1
access-list 10 permit tcp any host 1.1.1.1 eq smtp
access-list 110 permit tcp any host 1.1.1.1 eq smtp
Answer: Option
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.
Discussion:
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