Lectures notes for 2010 - KTH

Port numbers in three groups
Range
Purpose
0 .. 1023 System (Well-Known) Ports a
1024 .. 49151 User (Registered) Ports
49152 .. 65535 Dynamic and/or Private Ports
a. Roughly 300 well know port numbers remain unassigned and 38 reserved
Roughly 26k registered port numbers remain unassigned and 9 reserved
‘For the purpose of providing services to unknown callers, a service
contact port is defined. This list specifies the port used by the server
process as its contact port. The contact port is sometimes called the
"well-known port".’
http://www.iana.org/assignments/port-numbers
Linux chooses the local port to use for TCP and UDP traffic from this range:
$ cat /proc/sys/net/ipv4/ip_local_port_range
1024 29999
Maguire Port numbers in three groups 4: 9 of 74
maguire@kth.se 2010.03.21 Internetworking/Internetteknik