Multiple routers in one modem

[Goofygiggles]

SO. We have a Spectrum business plan, and they gave us a technicolor modem with 4 ethernet ports. We plugged our new Sonicwall router into port one and were off to the races with the ip x.x.x.210,


for craps and giggles, I plugged a second Sonicwall into the modem to see what would happen and it didn't work. I set it to DCHP to try to get it to work, and eventually set the router to the static ip x.x.x.208.


It works and I don't know why. We purchased one ip. Do I misunderstand how modems work?

 

[kanewolf]

If your technicolor device has 4 ports, then it may be a modem or it may be a router. Does your SonicWall get the public IP address you purchased?

 

[Goofygiggles]

If your technicolor device has 4 ports, then it may be a modem or it may be a router. Does your SonicWall get the public IP address you purchased?

We purchased the x.x.x.210 static IP address, so yes it gets it.
We didn't purchase the x.x.x.208 IP, but it works for some reason with my second Sonicwall.
The technicolor device is a modem set to "bridged mode."
I don't have enough understanding of how this works to know why this is, did Spectrum accidentally give us more than one IP? There isn't a problem, it's working and I am trying to understand WHY it's working.

 

[kanewolf]

So you are stealing an IP address. Your ISP isn't limiting your connection to the single IP you purchased. Because you have knowledge of the IP range that IS allowed on your link, you can pick a similar IP and it works. But there is no guarantee that your ISP won't sell that IP to someone or notice your theft and block your connection completely.

 

[Goofygiggles]

So you are stealing an IP address. Your ISP isn't limiting your connection to the single IP you purchased. Because you have knowledge of the IP range that IS allowed on your link, you can pick a similar IP and it works. But there is no guarantee that your ISP won't sell that IP to someone or notice your theft and block your connection completely.

Okay thanks.. I guess I figured if there weren't more ip addresses on our account they wouldn't let our modem use it.