I installed Openserver 5.0.7 and I cannot telnet to the localhost and I can't telnet from my old SCO 3.2.42 to the new SCO machine but I can ping the new machine and it will telnet to the old machine. (2 Replies)
I'm trying to use rsh command to read a variable on a remote machine. I can rlogin with no problem. If I rsh HOST I also get connection like with rlogin. There is no need for passwords. But when I rsh HOST COMMAND it waits 30 seconds then gives me a connection refused error message. Any ideas?
... (4 Replies)
Hi there,
Anything will help.
I have running server on computer and want to connect from some clients.
Server:
memset(&hints, 0, sizeof(hints));
hints.ai_family = domain;
hints.ai_socktype = SOCK_STREAM;
error = getaddrinfo("localhost", "8300", &hints, &res0);
if (error)
{
... (1 Reply)
Hi guys i am facing this issue while opening new xterm window.please help me out.
Xlib: connection to "delop125ld:0.0" refused by server
Xlib: Maximum number of clients reached
xterm Xt error: Can't open display: delop125ld:0.0
thanks (1 Reply)
Hi everyone,
I am hoping anyone of you could help me in this weird problem we have in 1 of our Solaris 10 servers. Lately, we have been having some ftp problems in this server. Though it can ping any server within the network, it seems that it can only ftp to a select few. For most servers, the... (4 Replies)
I dont' what happened with my servers (test servers only) but I just noticed that suddenly I cannot up the domain anymore (Sun Java System Application Server 9.1_01).
a. server.log
org.postgresql.util.PSQLException: Connection refused. Check that the hostname and port are correct and that the... (1 Reply)
Hi- While trying ftp from AIX to Windows im getting below error. Can anyone share ur views on this topic.
root@AB101# ftp -n 10.192.168.68
ftp: connect: A remote host refused an attempted connect operation.
ftp>
Thanks. (3 Replies)
Hi all,
i got stuck with telnet issue, I am not able to telnet on 4001 port it show connection refused.
with default port it will open
# telnet 127.0.0.1
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Fedora release 14 (Laughlin)
Kernel 2.6.35.6-45.fc14.i686 on... (1 Reply)
I have two computers running Debian 6.0 and one running Solaris 2.6 on a private network. The Debian computers can ftp to the Solaris computer but if a Debian computer is the destination the ftp connection is refused. I assume this is some security feature of Debian. What can I do to allow... (2 Replies)
Hi I am trying to execute a shell script which is in unix server gs1. The script is below which basically connects to another unix server q15 and tries to get a file using FTP .
But i get error as "ftp: connect: Connection refused
Not connected.
Not connected."
Please help with if the below... (8 Replies)
Discussion started by: samrat dutta
8 Replies
LEARN ABOUT DEBIAN
blackhole
BLACKHOLE(4) BSD Kernel Interfaces Manual BLACKHOLE(4)NAME
blackhole -- a sysctl(8) MIB for manipulating behaviour in respect of refused TCP or UDP connection attempts
SYNOPSIS
sysctl net.inet.tcp.blackhole[=[0 | 1 | 2]]
sysctl net.inet.udp.blackhole[=[0 | 1]]
DESCRIPTION
The blackhole sysctl(8) MIB is used to control system behaviour when connection requests are received on TCP or UDP ports where there is no
socket listening.
Normal behaviour, when a TCP SYN segment is received on a port where there is no socket accepting connections, is for the system to return a
RST segment, and drop the connection. The connecting system will see this as a ``Connection refused''. By setting the TCP blackhole MIB to
a numeric value of one, the incoming SYN segment is merely dropped, and no RST is sent, making the system appear as a blackhole. By setting
the MIB value to two, any segment arriving on a closed port is dropped without returning a RST. This provides some degree of protection
against stealth port scans.
In the UDP instance, enabling blackhole behaviour turns off the sending of an ICMP port unreachable message in response to a UDP datagram
which arrives on a port where there is no socket listening. It must be noted that this behaviour will prevent remote systems from running
traceroute(8) to a system.
The blackhole behaviour is useful to slow down anyone who is port scanning a system, attempting to detect vulnerable services on a system.
It could potentially also slow down someone who is attempting a denial of service attack.
WARNING
The TCP and UDP blackhole features should not be regarded as a replacement for firewall solutions. Better security would consist of the
blackhole sysctl(8) MIB used in conjuction with one of the available firewall packages.
This mechanism is not a substitute for securing a system. It should be used together with other security mechanisms.
SEE ALSO ip(4), tcp(4), udp(4), ipf(8), ipfw(8), pfctl(8), sysctl(8)HISTORY
The TCP and UDP blackhole MIBs first appeared in FreeBSD 4.0.
AUTHORS
Geoffrey M. Rehmet
BSD January 1, 2007 BSD