I see that in 6.20 the leases are changed from 3 days to 10 minutes. Could this cause devices to lose their ip address and temporarily lose connection? Im’ a little confused how this works.
can you point me to the area I need to focus on in the article? It’s really long!
The change in lease time should not be a problem. As long as the client device thinks it has a lease, even tho it is longer than the lease time on the dhcp server, it should not lose the connection.
The dhcp server (last I checked) will check to see if an IP is being used before issuing that IP from the dhcp pool. It pings that IP before assigning it to a device. If it gets a ping response on that IP, it marks that IP as “busy” in the lease list, and gets another IP from the pool.
You can check this if you wish.
/ip dhcp-server lease
print detail
got it. But by shortening the lease time to 10 minutes, doesn’t this tax the router and add network traffic? I wonder how it affects performance?
Yes, it affects the performance of the network, but that would be relational to the number of clients on the network. If there are only a few clients, the performance loss would be minimal.
You can change the lease time to any length you want. You can change it back to 3 days if you feel like it.
Thanks tim. On the same note, if I am running a script to ping all static ip addresses every 5 minutes, will this also tax the network, or is ping so minimal it doesn’t matter?
It shouldn’t tax the network too much, but again, it depends on the number of static IP clients you have on the localnet. If just a few, you will normally not notice the performance loss.
When renewing a dhcp lease there are only a few packets exchanged in the network. The client sends DHCPREQUEST for the ip it already has and the server replies with DHCPACK, that’s it.
It is so minimal that really is nothing to worry about. But this is just a default value for someone that installs a router without knowing much about settings.
Any network administrator can and should change the value to a setting that he thinks is best for his network.
I agree, the network admin should set it to what works best for the environment.
Tim, I usually don’t have many more than 20-30 static ips.
That will cause no noticeable effect. Ping is one packet from src to dst, and one packet back. Hardly a network killer, even if done 30 times every 5 minutes.