New answers tagged tcp
I have a feeling it's the DHT startup. When you first start the client, it's trying to join the DHT swarm (iirc the initial bootstrap node is node0.bittorrent.org) which would then pass you off to a bunch of other nodes, probably in a datacenter like AWS, before you get regular everyday nodes (other clients)
I think the program you are after is called ser2net. It bridges serial streams to TCP ports of your choice. In Ubuntu / Debian do the following: # apt-get install ser2net then edit /etc/ser2net.conf and set up a line such as this: 2000:telnet:600:/dev/ttyUSB0:115200 8DATABITS NONE 1STOPBIT banner and finally restart the service # systemctl restart ...
By definition on a layered model as OSI or TCP/IP each layer works independent and not-aware of the lower layers. When you remove the cable, it's a physical disruption (layer 1), so almost inmediately ethernet (layer 2) detects a loss of signal (if you're on Windows you will see the very dreaded pop-up informing network disconnected) IP (layer 3) and TCP ...
ss -a4 | less I'm assuming you're speaking about IPv4... If not, you can replace the 4 in the preceeding command with 6. The -a parameter is to show all ports (listening and non). You can add -n to the parameters if you don't want to resolve names in the display.
We have already good answers but there is yet another way to do it that would list all the connections made even if they are not active in some instant in the time: strace -e socket,connect,close -f -o hipchat.strace.txt hipchat The output would show you additional information like UDP requests and opened but closed connections.
ss utility from iproute package for Linux
Another tool that can do this is lsof: # lsof -i -a -p 1981 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME sshd 1981 root 3u IPv4 917 0t0 TCP host.example.com:ssh (LISTEN) # lsof -i -a -p 1981 -n COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME sshd 1981 root 3u IPv4 917 0t0 TCP 10.1.2.3:ssh (LISTEN) # lsof -i ...
You can use netstat for this. See the example (I grepped for ssh): netstat -putan | grep ssh tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1725/sshd tcp 0 0 18.104.22.168:45734 22.214.171.124:22 ESTABLISHED 2491/ssh tcp6 0 0 :::22 :::* LISTEN ...
You could try this (incoming traffic to port 1234 will be redirected to 4321 in the localhost, where you could have your script listening): iptables -I INPUT -p tcp --dport 1234 -j ACCEPT iptables -I INPUT -p tcp --dport 4321 -j ACCEPT iptables -t nat -I PREROUTING -p tcp --dport 1234 -j REDIRECT --to-ports 4321 If you want to access the port 1234 from ...
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