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### Know your public IP
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* `curl ifconfig.co`
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* `curl ident.me`
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### Block an IP with `iptables`
* `iptables -A INPUT -s 35.196.128.87 -j DROP`
### Undo the previous rule
* `iptables -D INPUT -s 35.196.128.87 -j DROP`
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### Watching active IP connections on Linux
Sources :
* [Joyent Support ](https://help.joyent.com/hc/en-us/articles/226687427-Watching-active-IP-connections-Linux ) - (2016) Watching active IP connections - Linux
* [Super User ](https://superuser.com/a/848966/453117 )
* [Server Fault ](https://serverfault.com/a/353134/298315 )
#### Incoming connections:
`watch -d -n1 lsof -i`
#### Trace all connections on specific port to `/var/log/messages` (syslog) using iptables :
`sudo iptables -I INPUT -p tcp --dport 443 --syn -j LOG --log-prefix "HTTPS SYN: "`
#### Trace all connections on specific port to `/var/log/messages` (syslog) using iptables :
`sudo iptables -I INPUT -p tcp --match multiport --dports 443,636,389,8095,80 --syn -j LOG --log-prefix "HTTPS SYN: "`
