CommView allows you to capture traffic on the loopback interface.
To start monitoring the loopback interface, select it from the
drop-down list in the toolbar.
Loopback packets are the packets sent/received within the same
computer, i.e. self-addressed packets. Typically, there is
virtually no loopback traffic on the standard PC. However, loopback
traffic is widely used by software developers for debugging
network-related applications. Therefore, CommView's loopback
capturing functionality is targeted primarily at this user
When you capture loopback traffic, the packets look exactly as any
other network packets, except that the checksums are not computed.
Please pay attention to the following peculiarities when capturing
captures loopback traffic on all of the local IP addresses. This
always includes 127.0.0.1/255.0.0.0, but may also include the IP
addresses of your Ethernet adapters, e.g. 192.168.0.1.
packets cannot be captured. Other IP protocols can (TCP, UDP,
successfully sent/received packets are captured. For example, if a
connection attempt fails because the destination port is closed,
you will not see any SYN / RST packets.
are silently closed; no FIN packets are captured.