Why should I assign static IP address on my DHCP server?
Hi.
I have installed isc-dhcp-server on a Debian. I'm making some experiments with this as I'm a little bit newbie on network administration.
I have read that you should assign static IP to any ethernet interface from where you want to serve IP addresses from your DHCP, but I don't really understand why.
I mean, why my DHCP server can't assign an IP address to "myself" ? All I need is to define a rank of IP addresses on dhcpd.conf, isn't it?
Thank you.
I have installed isc-dhcp-server on a Debian. I'm making some experiments with this as I'm a little bit newbie on network administration.
I have read that you should assign static IP to any ethernet interface from where you want to serve IP addresses from your DHCP, but I don't really understand why.
I mean, why my DHCP server can't assign an IP address to "myself" ? All I need is to define a rank of IP addresses on dhcpd.conf, isn't it?
Thank you.
One reason is that when a host tries to renew it's address, it will do so to the IP address of the server. If the server address changes, then it can't renew the address.
ASKER
I understand that the DHCP server need to have a FIXED address, but why couldn't it be assigned by the DHCP server itself?
I mean, DHCP server can assign fixed address to hosts, according to its MAC address...
I mean, DHCP server can assign fixed address to hosts, according to its MAC address...
It can, but what's the gain?
The primary function of DHCP is to ease in the deployment of hosts so you don't have to manually assign IP addresses. We're talking one host here. So there's no real gain to having this server get a dynamic address.
The primary function of DHCP is to ease in the deployment of hosts so you don't have to manually assign IP addresses. We're talking one host here. So there's no real gain to having this server get a dynamic address.
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Thank you both.
I think the clue is the IP broadcast address (255.255.255.255) where DHCP questions goes to. I didn't realiza that this means that request is going to the network, but not to myself.
I think the clue is the IP broadcast address (255.255.255.255) where DHCP questions goes to. I didn't realiza that this means that request is going to the network, but not to myself.
yes, any broadcast packet from self to broadcast address will be ignored.
but, again, the story starts at Link Layer (Layer 2) and there is NO IP address (Layer 3) at that moment. it is all about MAC address, its broadcast address is FF:FF:FF:FF:FF:FF (48 bits) instead of FF.FF.FF.FF (255.255.255.255 or 32 bits).
but, again, the story starts at Link Layer (Layer 2) and there is NO IP address (Layer 3) at that moment. it is all about MAC address, its broadcast address is FF:FF:FF:FF:FF:FF (48 bits) instead of FF.FF.FF.FF (255.255.255.255 or 32 bits).
ASKER
I have read that when no IP is assigned, DHCP client uses 0.0.0.0 as IP address, and 255.255.255.255 (=broadcast) as destination.
A lot of services (BIND, ISC-DHCP, etc..) bind to a certain IP address. If they were receiving DHCP addresses it would make it very hard to administer.