DHCP Best Practice for Remote Branches

[darrenriley5]

Hi,

What's the best practice for DHCP at remote branch offices? Configure DHCP on the Cisco routers or use the Microsoft DHCP at Head Office?

Of course if the WAN goes down the branches will have no ip connectivity but all applications are accessed over the WAN anyway.

Thanks                  

[Bilal Nawaz]

Hello, Im not sure if there is a best practice for this kind of thing but here's my opinion. In this case, for small/medium remote branch offices - i've seen local dhcp servers leasing out addresses.

Normally you would have resilient links in place just in the event of failure anyway.

But there are benefits of having DHCP onsite, if the WAN was to go down, you still have local facilities like printing, wireless on LAN etc...

Coming back to having your DHCP server in your WAN...

The leases are given out for a certain amound of time. It's only when this time expires and the event occurs, then you may experience problems.

In an ideal world we would have redundant WAN links.

Hope this helps

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

[darrenriley5]

These are small remote branch offices which will have resilient WAN links.  Just really wondering what others do. We are looking to move to a serveless branch so DHCP on a local server at the branch isn't an option, that leaves me with DHCP on the local cisco router or add the DHCP scopes on the DHCP server at head office and use dhcp relay. Initially my thoughts were to configure dhcp on the routers.

Many Thanks

[Bilal Nawaz]

In this case, I agree with you. It would be best to put the DHCP services on the router itself. This is a popular theme in small branch offices and is a v.good solution.

Hope this helps

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

[iores]

Hi,

let's say there are 45 branch offices and DHCP server is located at Headquarters.

Does this mean that every branch office will use its unique subnet range(s)? In other words, if location A uses 192.168.0.0/24, this range won't be used at some other location?

[paul driver]

Hello
Yes it would and as each site only as a single wan connection then resiliency wouldn’t be viable for the wan connection but could still be achieved  for a centralized dhcp service.

[iores]

Hi Paul,

I do not understand this part of your reply: ...then resiliency wouldn’t be viable for the wan connection but could still be achieved  for a centralized dhcp service.

Do you mean that since the WAN connection goes via remote location, if that location goes down then the WAN connection will go down as well.

But for centralized DHCP connections there is still a way to ensure redundant DHCP connections?

Is my understanding right?

[Joseph W. Doherty]

In the past, I've generally only seen DHCP leasing from a "central" location (usually having more than one DHCP [non-network device] server [in case one fails]).

Also, usually, in such environments, DHCP addresses are leased for at leased a day, or for a much as a week.  So, usually there's not a major lost of DHCP hosts before a remote connection or DHCP service can be restored.

Also, the businesses I've worked for with tend to be very large Enterprises, and their networks are often supported by different functional groups.  I.e. the group supporting something like DHCP servers often wouldn't have access to remote network device (i.e. routers or switches); as likewise the group supporting such remote network devices not having (operational/configuration) access to DHCP servers.

BTW, not saying the forgoing might be considered a "best practice", but don't recall any operational issues caused by using the forgoing approach.

[Elliot Dierksen]

Since I have been a network infrastructure person for some time, I generally prefer to do that sort of thing in the network infrastructure. Server/MS people tend to prefer centralized MS DHCP which does have some benefits. To me the big thing is if there are network resources available when the connection to centralized DHCP is list. If so, I would probably tend to do it locally in the infrastructure. If there aren't local network resources that can be used then it is just a matter of personal/organization preference. All IMHO, of course!