The BIG-IP has two distinct planes:

Management-plane→ handled entirely by the management interface (MGMT)

Data-plane (TMM)→ handles Self IPs, VLAN interfaces, and traffic processing

To capture traffic on the management interface, only the management-side NICs may be used:

mgmt→ Logical name for the management interface

eth0→ Physical Linux interface mapped to the management port on most BIG-IP platforms

Both of these correctly capture inbound/outbound WebUI (HTTPS/443) traffic on the management port.

Why the correct answers are A and B

A. tcpdump -i eth0 -n port 443

On BIG-IP appliances and VMs, the management port maps toeth0at the Linux OS level.

Capturing on eth0 correctly shows HTTPS traffic to the WebUI.

B. tcpdump -i mgmt -n port 443

mgmtis the BIG-IP alias for the management interface.

This is thepreferredand most explicit capture interface for management-plane packet captures.

Why the other options are incorrect:

C. tcpdump -i 0.0

Interface0.0is the TMM switch interface used for data-plane packet captures.

Itdoes NOTcapture management-plane traffic.

D. tcpdump -i tun0

Used for tunnel interfaces (IPsec, VXLAN, etc.)

Not related to management access.

E. tcpdump -i management

There isnointerface named management on BIG-IP.

The correct names are mgmt or eth0.