C.2 Standard Internet
Services
Be familiar with the standard Internet services
described in Figure 2.18. We have
used the daytime service many times for testing our clients. The
discard service is a convenient port to which we can send data. The
echo service is similar to the echo server we have used throughout
this text.
Many sites now prevent access to these services
through their firewalls because of some denial-of-service attacks
using these services in 1996 (Exercise 13.3).
Nevertheless, you can hopefully use these services within your own
network.
|
