LTM Issue: No Record of Port 1990 in TCP Dump

F5 301b Question Answer

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Refer to the exhibit.

A company uses a complex piece of client software that connects to one or more virtual servers (VS) hosted on an LTM device. The client software is experiencing issues. An LTM Specialist is tasked with finding the cause of the problem.

The LTM Specialist has the tcpdump extract and knows the client software has at least one connection to a VS on port 1990. However, when a tcpdump runs on the internal VLAN, there is no record of port 1990 in the tcpdump.

Why is there no record of port 1990 in the tcpdump?

The LTM device drops the connection.

Port 1990 is a well-known port, so its use is restricted.

The LTM device performs a Port Address Translation (PAT).

The LTM device performs a Network Address Translation (NAT).