Porty mensi nez 1000 [vyřešeno]

[mizik]

Ahoj,
zkousel jsem vytvorit server s portem 992 ci 993, funkce bind probehne neuspesne (presne errno jsem nezkoumal). Pokud naopak posloucham na portu 1992 ci 1993 je vse ok.

Z toho usuzuju, ze snazit se poslouchat na portu < 1000 neni ok, je to tak?
Nekde jsem cetl,ze se to nedoporucuje...?

Na googlu jsem toho moc nenasel, jen ze tyto porty se pouzivaji pro :
992 telnet over TLS/SSL.
993 imap4 over TLS/SSL.
ci
993 TCP Mail IMAP SSL

Toz muzete mi hodit nejakej uzitecnej link, ci strucne napsat male info?
Pripadne je mozne nejak zaridit abych mohl na tomto portu poslouchat?

Diky

ps. pouzivany jazyk c/c++
ps2. podle netstats -t tento porty 992,993 nejsou pouzivane (obazene)

Kód: [Vybrat]

Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 10.161.0.200:ssh        172.16.18.68:2668       ESTABLISHED
tcp        0      0 10.161.0.200:ssh        172.16.18.68:1540       ESTABLISHED
tcp        0      0 10.161.0.200:ssh        172.16.18.68:1539       ESTABLISHED
tcp        0    216 10.161.0.200:ssh        172.16.18.98:4560       ESTABLISHED
tcp        0      0 10.161.0.200:ssh        172.16.18.68:1842       ESTABLISHED


[jfoot]

Zdravím Vás,

zde je kousek infa , není to zrovna hezky zformátované , ale snad To svůj informační účel splní...

Věřím tomu, že na Linuxu bude něco podobného jako tohle :

a fairly complete listing of assigned ports is stored in the file /etc/services.

2.3.2 Ports
Addresses would be all you needed if each computer did no more than one thing at a
time. However, modern computers do many different things at once. Email needs to
be separated from FTP requests, which need to be separated from web traffic. This is
accomplished through ports. Each computer with an IP address has several thousand
logical ports (65,535 per transport layer protocol, to be precise). These are purely
abstractions in the computer's memory and do not represent anything physical like a
serial or parallel port. Each port is identified by a number from 1 to 65,535. Each port
can be allocated to a particular service.
For example, the HTTP service, which is used by the Web, generally runs on port 80:
we say that a web server listens on port 80 for incoming connections. SMTP or email
servers run on port 25. When data is sent to a web server on a particular machine at a
particular IP address, it is also sent to a particular port (usually port 80) on that
machine. The receiver checks each packet it sees for the port and sends the data to any
programs that are listening to the specified port. This is how different types of traffic
are sorted out.
Port numbers from 1 to 1023 are reserved for well-known services such as finger, FTP,
HTTP, and email. On Unix systems, only programs running as root can receive data
from these ports, but all programs may send data to them. On Windows and the Mac,
including Windows NT, any program may use these ports without special privileges.

Table  shows the well-known ports for the protocols that are discussed in this book.
These assignments are not absolutely guaranteed; in particular, web servers often run
on ports other than 80, either because multiple servers need to run on the same
machine, or because the person who installed the server doesn't have the root
privileges needed to run it on port 80. On Unix systems, a fairly complete listing of
assigned ports is stored in the file /etc/services.

Table     Well-known Port  Assignments
Protocol    Port          Protocol Purpose
echo 7      TCP/UDP    Echo is a test protocol used to verify that two machines are able to connect by having one echo back the other's input.

discard  9   TCP/UDP    Discard is a less useful test protocol in which all data received by the server is ignored.
daytime 13  TCP/UDP Provides an ASCII representation of the current time on the server.
ftp-data 20  TCP FTP uses two well-known ports. This port is used to transfer files.
FTP       21  TCP This port is used to send FTP commands like put and get.
Telnet    23  TCP Telnet is a protocol used for interactive, remote command-line sessions.
SMTP     25  TCP The Simple Mail Transfer Protocol is used to send email between
machines.
time       37  TCP/UDP
A time server returns the number of seconds that have elapsed on the
server since midnight, January 1, 1900, as a 4-byte, signed, big-endian
integer.
whois     43 TCP Whois is a simple directory service for Internet network administrators.
finger     79 TCP Finger is a service that returns information about a user or users on the
local system.
HTTP     80 TCP Hypertext Transfer Protocol is the underlying protocol of the World Wide
Web.
POP3    110 TCP Post Office Protocol Version 3 is a protocol for the transfer of
accumulated email from the host to sporadically connected clients.
NNTP    119 TCP Usenet news transfer is more formally known as the Network News
Transfer Protocol.
RMI
Registry 1099 TCP This is the registry service for Java remote objects. This will be discussed
in Chapter 18.

[mizik]

Dekuji za rychlou a presnou odpoved.

[jfoot]

Zdravím Vás,

ni za što, rádo se stalo. Nicméně nedalo mi to a pogooglil (hrozné sloveso, zní to skoro jako 'poblil'... ) jsem trochu . Pokud zadáte do google třeba tento řetězec :

assigned ports on Linux

tak hned první odkaz pojednává o blokaci portu...

[Martin - ViPEr*CZ*]

Jen takovej dotaz? Měl jste ten server k otestování spuštěný jako root?

[mizik]

Ne ne, jako root ne.
Duvod Vaseho dotazu je asi :

On Unix systems, only programs running as root can receive data
from these ports, but all programs may send data to them

pokud bych to spoustel pod rootem, problem by tedy pravdepodobne nenastal.

[mizik]

Zdravím Vás,

ni za što, rádo se stalo. Nicméně nedalo mi to a pogooglil (hrozné sloveso, zní to skoro jako 'poblil'... ) jsem trochu . Pokud zadáte do google třeba tento řetězec :

assigned ports on Linux

tak hned první odkaz pojednává o blokaci portu...

Ok, diky. Bohate mi zatim stacila prvni odpoved. Pripadne mrknu na dany odkaz.

[Martin - ViPEr*CZ*]

Ne ne, jako root ne.
Duvod Vaseho dotazu je asi :

On Unix systems, only programs running as root can receive data
from these ports, but all programs may send data to them

pokud bych to spoustel pod rootem, problem by tedy pravdepodobne nenastal.

presně to jsem měl na mysli ;-)

[Martin Kiklhorn]

balík privbind

nebo zagooglete něco ve smyslu "how to bind with privileged port"