Personal ip addresses

[snazzyconnor]

Hi, on the rules I saw not to put the private addresses up because it makes you vulnerable to attacks.
From how I understand IP works, you have a personal(private) one for the local network for the router or other machine to send data to you and a public one which is the same as the router.
Also I believe all private ip addresses are within a select range for all local networks? So surely all it does is provide a shortcut right? All an attacker would have to do is ping every device on the network range and they'd know there's a device there, assuming they have not disabled icmp.

 

[USAFRet]

Hi, on the rules I saw not to put the private addresses up because it makes you vulnerable to attacks.
From how I understand IP works, you have a personal(private) one for the local network for the router or other machine to send data to you and a public one which is the same as the router.
Also I believe all private ip addresses are within a select range for all local networks? So surely all it does is provide a shortcut right? All an attacker would have to do is ping every device on the network range and they'd know there's a device there, assuming they have not disabled icmp.

That points to not posting your public IP address. What the ISP gives you.
But if I know that, scanning everything in 192.168.1 xxx is trivial. And for the VAST majority of home networks, your PC and all other devices in your house will be in that range.

 

[snazzyconnor]

Hi, on the rules I saw not to put the private addresses up because it makes you vulnerable to attacks.
From how I understand IP works, you have a personal(private) one for the local network for the router or other machine to send data to you and a public one which is the same as the router.
Also I believe all private ip addresses are within a select range for all local networks? So surely all it does is provide a shortcut right? All an attacker would have to do is ping every device on the network range and they'd know there's a device there, assuming they have not disabled icmp.

That points to not posting your public IP address. What the ISP gives you.
But if I know that, scanning everything in 192.168.1 xxx is trivial. And for the VAST majority of home networks, your PC and all other devices in your house will be in that range.

Oh I see, makes far more sense, I must have read it wrong

 

[Rookie_MIB]

Actually - what you have is this, assuming a typical type of ISP (Comcast, Verizon etc).

cable modem: connects to your cable system, connects with head office, turns the data coming in (QAM-64 or QAM-256) into digital IP packets which your computer can understand and vice versa.

router: usually integrated into the cable modem these days. It's public facing IP address is assigned by the cable company (either dynamic or static depending on your type of account). It also has an internal facing IP address which you can set and/or assign, and usually runs DHCP to assign other IP addresses to your internal network and provide WIFI connections. DHCP usually operates within a range you can set depending on your network needs and you can set it to whatever range you desire.

Generally, for most people you're not going to be able to be pinged on your internal network by an outside source if each device doesn't have a unique public facing IP. The only thing that could get pinged would be the routers (cable modems) public facing IP address as there's no way to 'tunnel' it through the router.