Maximum Time difference between DHCP primary and DHCP failover Server

Thomas Markwalder tmark at
Tue Jan 19 13:03:52 UTC 2021

This is going to vary largely on site dynamics. The primary challenge to 
failover performance, is that it is a synchronous protocol.  Servers are 
supposed to wait until their peers acknowledge that a least update has 
been received prior to sending the corresponding response (i.e. DHCPACK) 
to the client.

In other words, this adds the round trip latency to the response time 
for a given client's DHCPREQUEST.  If DHCPREQUESTs are coming in too 
fast, the server will fall behind and clients will stop getting 
responses. If you need as sustained 10 DORAs a second, then 250ms 
round-trip latency between the peers is going to be a deal breaker.

I'm sure others on this list will have plenty to share on the subject.

On 1/19/21 6:38 AM, kraishak wrote:
> Hi Thomas,
> Thanks for sharing information, Can you also please comment or share your
> experience if you have any, about what could be the maximum network latency
> between the primary and failover DHCP servers that does not impact the
> server performance
> Thanks in advance
> Kraishak
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