ip address and dhcp

jamesleecoleman

Hey!!!

I'm confused with assigning ip addresses with interfaces. I know how to assign them to the interface but I don't understand why my computer thats hooked up to the switch doesn't get an ip address. I thought the interface would have given out ip addreses automatically. The only time is when I get an ip address is when I assign a dhcp address in the global config. Then assign an ip address that is the same ip / mask to that interface. That is when I get ip addresses to the computers. Then only one interface assigns ip addresses and the other doesn't. Would I have to make two different pools for both addresses?

captobvious

jamesleecoleman wrote: »

Hey!!!

I'm confused with assigning ip addresses with interfaces. I know how to assign them to the interface but I don't understand why my computer thats hooked up to the switch doesn't get an ip address. I thought the interface would have given out ip addreses automatically. The only time is when I get an ip address is when I assign a dhcp address in the global config. Then assign an ip address that is the same ip / mask to that interface. That is when I get ip addresses to the computers. Then only one interface assigns ip addresses and the other doesn't. Would I have to make two different pools for both addresses?

You're talking about a switch, right? What does a switch do?

jamesleecoleman

captobvious wrote: »

You're talking about a switch, right? What does a switch do?

Oops sorry!! I ment a router.

elegua

jamesleecoleman wrote: »

Hey!!!

I'm confused with assigning ip addresses with interfaces. I know how to assign them to the interface but I don't understand why my computer thats hooked up to the switch doesn't get an ip address. I thought the interface would have given out ip addreses automatically. The only time is when I get an ip address is when I assign a dhcp address in the global config. Then assign an ip address that is the same ip / mask to that interface. That is when I get ip addresses to the computers. Then only one interface assigns ip addresses and the other doesn't. Would I have to make two different pools for both addresses?

Are you running a DHCP on the router?, can you please explain a little bit more?, i'm not getting what you are asking.

jamesleecoleman

Do I have to run dhcp on the router in order for the pcs on my network to get an ip address or can I just configure an ip addres on the interface and then my pcs get an ip address? I thought if I configured an fa interface with an ip address, on a router then it would automatically give out ip addresses.

elegua

jamesleecoleman wrote: »

Do I have to run dhcp on the router in order for the pcs on my network to get an ip address or can I just configure an ip addres on the interface and then my pcs get an ip address? I thought if I configured an fa interface with an ip address, on a router then it would automatically give out ip addresses.

Yes, you have to run DHCP in your router;

This is assuming that you're using a cisco router:

Router-----Switch-----PC's

If you want that all PCs in your network got an IP you have to run the service in the router unless you are running a DHCP server:

config mode:

service dhcp

Then you have to create the pools:

Ex:

ip dhcp pool MyNETWORK
   import all
   network 192.168.1.0 255.255.255.0
   default-router 192.168.1.1 
   dns-server  4.2.2.2 
   lease 2
   update arp

If you want to assign static IPs to any PC then try this:

ip dhcp pool MyPC
   host 192.168.1.5 255.255.255.0
   client-identifier 01XX.XXXX.XXXX.XX
   lease infinite

XX.XXXX.XXXX.XX will be your Mac Address.

If you want to exclude some IPs then try this:

ip dhcp excluded-address 192.168.1.1 192.168.1.5

If you have this and still your PC's don't get an IP address then try some sh cmds to verify:

sh ip dhcp binding

This will tell you if your DHCP is assigning IPs

Hope this help.