Modem And Router

[MichaelKing]

I'm currently studying for the Network+ Certification Test, so far I have a good grasp on things but something has got me stumped. I was looking at the settings for my Wireless Router and Modem, the modem is set as a DHCP server, as is the Router. Wouldn't having two DHCP servers cause problems? When I run Ipconfig it shows the default gateway at an address of 192.168.1.1...When I take a look at the modem settings, it shows the Default Gateway with an address of 192.168.254.254.

Two DHCP Servers???
Two Default Gateways???

Could someone please explain this to me. Shouldn't I have one DHCP server and one Default Gateway?.........Possibly these two are provided as backups???

BTW: Everything is working, I was just curious as to why two DHCP Servers and two Default Gateways have been specified.

Thanks,
Mike

 

[hiren]

Usually two DHCP servers shouldn't create problem unless there ip address scopes overlaps.

The function of DHCP server is to provide ip address automatically only so you can have multiple DHCP servers.

Actually your modem should be able to give your actual ip address as DHCP server because it is the point of contact with the outside world.

Could you tell me is it cable modem?

 

[MichaelKing]

It's a DSL Modem.

 

[technogab]

Your DSL modem will have the actual outside IP address. Something like 24.17.234.102 (I just chose random number here). Anyway the 192.168.1.x will be the IP's on your internal network. Your router is going to be the default gateway which will be 192.168.1.1. That is the gateway for all your internal devices to get to the router. Your router will have a default gateway of the outside world of your DSL provider.

It's fine to have 2 DHCP servers but there is no need. Just disable the one on your modem so you are only getting IP's from your router, let it then route the traffic to your modem as it's supposed to. Or you can disable DHCP on the router instead. But you will see 2 default gateways, 1 for the internal network that is for the inside, and 1 on your modem that connects you to the outside world.