Re: How to open port 22 on Centos? Post by michaelnel » Tue Dec 29, 2009 5:40 pm If you change the ssh port (and I agree, you should) don't forget to change the iptables firewall to match.
May 26, 2020 linux - How can I port forward with iptables? - Server Fault 2) Add 2 iptables rules to forward a specific TCP port: To rewrite the destination IP of the packet (and back in the reply packet): iptables -A PREROUTING -t nat -p tcp -i ppp0 --dport 8001 -j DNAT --to-destination 192.168.1.200:8080 To rewrite the source IP of the packet to the IP of the gateway (and back in the reply packet): linux - IPtables - opening ports not working - Server Fault You want to open port 18819 for incomming connections, the protocol is tcp and the source can be anything, the interface is probably eth0: iptables -A INPUT -i eth0 -p tcp --dport 18819 -j ACCEPT Also, don't lock yourself out of the system: iptables -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT 14.04 - How to open port 22 with iptables - Ask Ubuntu So, I logged in to a different instance with the same security group and trying to run this sudo iptables -A INPUT -d 10.xxx.xxx.xx -p tcp --dport 22 -j ACCEPT but that didn't open the port 22 on that instance . Output of the above iptables commands is none. from the instance where I was able to login:
Dec 09, 2019 · By default SSH uses port 22 and again uses the tcp protocol. So if we want to allow remote logins, we would need to allow tcp connections on port 22: # Accept tcp packets on destination port 22 (SSH) iptables -A INPUT -p tcp --dport 22 -j ACCEPT. This will open up port 22 (SSH) to all incoming tcp connections which poses a potential security
The command to open the port I already tried was: sudo iptables -A INPUT -p tcp --dport 8092 -j ACCEPT and it didn't open the port. I also was told to run this command to open the port which maybe could help: iptables -t nat -A PREROUTING -i lo -p tcp -d 127.0.0.1 --dport 8092 -j DNAT --to-destination 192.168.1.202:8092
The command to open the port I already tried was: sudo iptables -A INPUT -p tcp --dport 8092 -j ACCEPT and it didn't open the port. I also was told to run this command to open the port which maybe could help: iptables -t nat -A PREROUTING -i lo -p tcp -d 127.0.0.1 --dport 8092 -j DNAT --to-destination 192.168.1.202:8092
May 01, 2004 How to use IPTables to block all SSH traffic (port 22 Blocking traffic to port 22 (SSH) is one of the first steps you should take when hardening a server. Locking down port 22 not only keeps unwanted people from gaining access to your server, it also helps prevent a certain type of DDoS attacks called SYN floods.Using IPTables and a whitelist approach is the quickest and easiest ways to accomplish this.