DHCP in a Data Center

[jason s]

Can anyone please explain the advantages and disadvantage associated with having DHCP in a Data Center?

[NCHosting]

Pros:

* DHCP with reservations allows centralized management of your address space. A single place for administrators to reference and edit your address space without necessarily having to reference the namespace (DNS). This is particular great if your administrators naturally "split" in duties at the network layer.
* DHCP can provide the ability to dynamically assign resources with correct ip in the address space. A reinstalled server comes up with the correct IP immediately without consultation.
* Dynamic allocation is particularly great for rapid server deployment, where automation handles the majority of system installation.

Cons:

* DHCP providers a point of failure that can prevent network access. (It's particularly nasty if one forgets to lower the time out for the dhcp client.)
* Network design must consider DHCP broadcast traffic. This can complicate routing and provide another level of potential failure for network access.
* Managing DNS and DHCP separately is considered burdensome by some.
* A failed DHCP assignment can result in the 169 network being created, firewalls and routers should be suitably prepared.

Very rarely is it wise to run DHCP in a data center without reservations, though some blend is appropriate. In many settings, the "Cons" for DHCP with reservations end up being non-issues (if the router can take out DHCP, well, the servers aren't accessible anyway, etc). It's also commonly a decision regarding size. A datacenter with hundreds or thousands of servers with frequent deployments and reinstallation will certainly use some DHCP, even if it's only for testing/deployment. A datacenter with a few servers will likely be fine with everything statically assigned.

[BodShane]

Originally Posted by NCHosting

Pros:

* DHCP with reservations allows centralized management of your address space. A single place for administrators to reference and edit your address space without necessarily having to reference the namespace (DNS). This is particular great if your administrators naturally "split" in duties at the network layer.
* DHCP can provide the ability to dynamically assign resources with correct ip in the address space. A reinstalled server comes up with the correct IP immediately without consultation.
* Dynamic allocation is particularly great for rapid server deployment, where automation handles the majority of system installation.

Cons:

* DHCP providers a point of failure that can prevent network access. (It's particularly nasty if one forgets to lower the time out for the dhcp client.)
* Network design must consider DHCP broadcast traffic. This can complicate routing and provide another level of potential failure for network access.
* Managing DNS and DHCP separately is considered burdensome by some.
* A failed DHCP assignment can result in the 169 network being created, firewalls and routers should be suitably prepared.

Very rarely is it wise to run DHCP in a data center without reservations, though some blend is appropriate. In many settings, the "Cons" for DHCP with reservations end up being non-issues (if the router can take out DHCP, well, the servers aren't accessible anyway, etc). It's also commonly a decision regarding size. A datacenter with hundreds or thousands of servers with frequent deployments and reinstallation will certainly use some DHCP, even if it's only for testing/deployment. A datacenter with a few servers will likely be fine with everything statically assigned.

I guess i don't need to say anything here....

Thanks NC!

[Roy Mills]

Originally Posted by NCHosting

Pros:

* DHCP with reservations allows centralized management of your address space. A single place for administrators to reference and edit your address space without necessarily having to reference the namespace (DNS). This is particular great if your administrators naturally "split" in duties at the network layer.
* DHCP can provide the ability to dynamically assign resources with correct ip in the address space. A reinstalled server comes up with the correct IP immediately without consultation.
* Dynamic allocation is particularly great for rapid server deployment, where automation handles the majority of system installation.

Cons:

* DHCP providers a point of failure that can prevent network access. (It's particularly nasty if one forgets to lower the time out for the dhcp client.)
* Network design must consider DHCP broadcast traffic. This can complicate routing and provide another level of potential failure for network access.
* Managing DNS and DHCP separately is considered burdensome by some.
* A failed DHCP assignment can result in the 169 network being created, firewalls and routers should be suitably prepared.

Very rarely is it wise to run DHCP in a data center without reservations, though some blend is appropriate. In many settings, the "Cons" for DHCP with reservations end up being non-issues (if the router can take out DHCP, well, the servers aren't accessible anyway, etc). It's also commonly a decision regarding size. A datacenter with hundreds or thousands of servers with frequent deployments and reinstallation will certainly use some DHCP, even if it's only for testing/deployment. A datacenter with a few servers will likely be fine with everything statically assigned.

very well explained thanks for the information