In terms of your script itself as a solution to your problem, a change like this should work:
This will cause the first TCP port that cannot have a blank line written to it by the echo command to be echoed out to standard output. The key is the return statement, which will cause the function to end as soon as it is executed. So once we find the first port we can't write a blank line to, we print it out and return control to the next line of the script (which doesn't exist, and so the script ends at that point).
Now, a better question: what is it you actually need to do here, and why ? This script might well work for certain ports in certain circumstances, but a far better bet here would be to use a utility that is dedicated to the purpose of port scanning (like nmap, for example) rather than trying to re-invent the wheel with a shell script.
sco unix 5.0.x, several weeks ago, I add a telnet-like service in inetd.conf, it runs well for 100 network terminals.
But nowdays, the terminals can connect to server successfully after booting machine, but several hours later, can not connect. "netstat -p tcp -a" can NOT find the port in... (1 Reply)
May I know what is the TCP/UCP port range for any default AIX NFS? Based on rpcinfo -p, I got the following output:
program vers proto port service
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100000 4 ... (4 Replies)
Hi Everyone,
In my environment, I have few T5220. On the iLOM Management Card, I have both Network and Serial port are cabled, I don't have any issues while I try to connect using Network Management port, but when I try to connect the serial port for the same server which is actually connected... (3 Replies)
Hello
I'm beginner in the linux scripting and i would like to get help. I want to create a script that can block one or more Port even see all the TCP port. The ports must be blocked even when starting my machine.
Of course requires a second script which will allow the ports that you want to... (0 Replies)
Hi Guys,
Please could you tell me if it is possible to have a single rule/filter to allow a certain port range instead of a separate rule for each port?
I'm sure it must be possible but I am unable to find the syntax.
Thanks
Chris (4 Replies)
I want to limit all *outbound* traffic on eth0 (or all *.*) on port 25 to a specific (allowed) range...
I.E.
192.168.1.5 (local ip) tries to connect to 1.2.3.4:25 (outside real world ip)
It can proceed because 1.2.3.0/24 is the allowed range
Now, 192.168.1.5 (local ip) tries to connect to... (1 Reply)
In my Linux system ephemeral port range is showing different ranges as follows
$ cat /proc/sys/net/ipv4/ip_local_port_range
32768 61000
cat /etc/sysctl.conf | grep net.ipv4.ip_local_port_range
net.ipv4.ip_local_port_range = 9000 65500
Which will be the effective ephemeral port... (5 Replies)
I'll start with I'm not an AIX expert, I inherited a lot of AIX servers to maintain.
My problem is on AIX 7.1 TL4 SP4 environments. I'm running named as a DNS forwarder only to internal DNS servers.
These AIX servers have a customized UDP ephemeral port range to avoid conflicting with the... (0 Replies)
Discussion started by: seanc
0 Replies
LEARN ABOUT OSF1
port_names
ports(7) Miscellaneous Information Manual ports(7)NAME
ports, port_names - Device (tty and lp) names for serial and parallel ports
SYNOPSIS
Default Serial Ports:
/dev/tty00
/dev/tty01 (not present on a single-port system)
Parallel Port:
/dev/lp0
DESCRIPTION
AlphaStation and AlphaServer systems provide one or two 9-pin serial communication ports. These ports are usually labelled 1 (COMM1) and 2
(COMM2), but they may be identified by different icons. Using the appropriate serial cable and terminator, you can connect a serial
printer, external modem, or character-cell terminal to a serial port. Most AlphaStation and AlphaServer systems also provide one parallel
port, for use with a parallel printer.
When you add a device to your system, the installation documentation may instruct you to map the device pathname to the port. These
devices are located in the /dev directory.
For serial-line ports, the two default device pathnames are: This pathname always maps to 1, COMM1, the lowest port number, an icon for a
terminal console, or the only serial port (on a single-port system). This pathname always maps to 2, COMM2, the next numbered port, or (if
one serial port is labeled with an icon for a terminal console) the remaining serial port.
If your system hardware has been extended to include additional serial ports, the pathnames /dev/tty02, /dev/tty03, and so forth, may also
be available to you. However, most systems have only /dev/tty00 and /dev/tty01 as the device pathnames for serial ports.
The one parallel port on an AlphaStation or AlphaServer may be labeled with the word printer or a printer icon. On some systems, the paral-
lel port may not be labeled. The device pathname for the parallel port is /dev/lp0. Currently, Tru64 UNIX does not fully support parallel
printers, so fewer devices are connected to this port as compared to serial ports.
If you are connecting a terminal console to your system, it must be connected to the serial port mapped to /dev/tty00. For other serial
devices, it does not matter which of the serial ports you choose for the connection. For example, suppose you are setting up a system that
has two serial ports, labeled 1 and 2. You intend to use a serial-line terminal rather than a workstation monitor as the system console and
also want to connect a serial-line printer to the system. In this case, you must connect the terminal to the port labeled 1 (with the
device pathname /dev/tty00). Therefore, you must connect the printer to the remaining port labeled 2 (with the device pathname /dev/tty01).
If, for the same type of system, you intend to use a workstation monitor as the system console, it does not matter which serial port you
use for a serial-line printer or modem. In other words, you can connect the printer to either port 1 (with pathname /dev/tty00) or port 2
(with pathname /dev/tty01). When prompted to enter a /dev/tty** pathname by the lprsetup script or the Print configuration tool in the CDE
Application Manager, you would specify /dev/tty00 if you connected the printer to port 1 or /dev/tty01 if you connected the printer to port
2.
See the System Administration manual for more information on setting up consoles (including remote consoles) and printers. See the
modem(7) reference page for more information on setting up modems.
SEE ALSO
Commands: lprsetup(8)
Devices: ace(7), modem(7)
System Administration delim off
ports(7)