DHCP "HOST" Settings 1H vs 5H vs 13H

Conserving resources is always a wise strategy.   The node storing in memory the definition of a subnet, regardless if 1, 5, or 13 devices, is still the same memory footprint.  For example,  this would look like 10.11.12.1/30, 10.11.12.1/29, or 10.11.12.1/28.   There's not an option in the UI to turn off the LAN subnet and free up the memory.  We'd need to add an option to enable this in a future firmware version.    Turning off DCHP would save a few memory bytes on the one node.  

The issue with th 1, 5, and 13 addresses and limiting the count is to avoid an IP address conflict.   However, if one were to ever occur, a manual correction readily resolves.   To put into perspective, we have 2^24 bits of address space in 10.x.x.x.    This is 16,777,216 possible addresses.   Each node would consume:

WAN - 1 Address
DtDLink - 1 Address
LAN -  4, 8, or 16 Addresses (for 1, 5, and 13 devices)

Thus we can have this many mesh nodes to fully consume the address space: 

if everyone had 13 LAN devices - 932,067 max mesh nodes
if everyone had 5 LAN devices   -  1,677,721 max mesh nodes
if everyone had 1 LAN device     -  2,796,202 max mesh nodes

We'd have to known how Ubiquiti assigns MAC addresses with the 4 or 5 manufacture #s assigned to them to determine the probability of an IP conflict.  But we'd likely need to see a contiguous mesh network reach 100,000s of mesh nodes before there's any meaningful risk of an IP address conflict.

Joe AE6XE

Joe,

Correct me if I'm wrong, but the OSLR traffic is mostly affected by the number of advertised services and the information along with those services (ip address, service name, url if applicable, etc.). Thus, in the context of saving OLSR traffic, any unused advertised services should be deleted and no longer advertised. I've seen in a typical nodes list that many advertised services are unreachable, probably because the machine behind that is off line, sometimes for months on end.

To Tom's point, something to keep in mind: If you do downsize (or change size either way), any services or hosts on that node will get a new ip address due to the algorithm that generates the DHCP address range. Thus, if you advertise phones with an ip address so that people can reach them by direct ip dialing, those advertisements will need to change. If the phone only has to register with a pbx, no change has to be made. In fact, the phone does not even have to advertise itself if no direct ip dialing is involved. Only the pbx has to know the ip address of the phone and that is done automatically when the phone registers itself.

Mark