[TriLUG] dhcp relay question

[John Beimler]

Chris Hedemark wrote:

>On Tuesday, May 13, 2003, at 08:43 AM, Mike Johnson wrote:
>  
>
>>Yes.  DHCP is ethernet broadcast, which is not repeated by layer 3
>>(routers) devices (normally), only layer 2 (switches/hubs).  If you
>>set your routers to relay DHCP, they'll do what you want.
>>    
>>
>
>Note that most Cisco devices allow you to enable a DHCP helper to have 
>a client on one network use a DHCP server on another.  It works pretty 
>well in a LAN environment but I wouldn't trust it over WAN (WAN link 
>goes down, suddenly DHCP leases aren't renewing and you can't even get 
>  
>
>to the local resources).
>

We use it here, our DHCP server is in Florida, over a fractional T1.  
Getting a DHCP lease take about a minute on a good day, if you try when 
our bandwith is saturated, it can take five minutes.  And as Chris 
stated, when the WAN link dies, your stations with DHCP are a pain to 
reconfigure so you can use them. Linux/BSD DHCP servers are easy to set 
up, I'd just put in a small one at every site, it will make life easier.

Peace.

john