2

I am working at a school and recently there has been more and more devices that are not getting internet due to dhcp table being full. Pool size of our ip addresses is set to 242, but there are more than 250+ devices connected sometimes and then the problem starts with some students not getting IP address due to the pool size being full. The default lease time was set to 24 hours, but I changed that now to 12 hours hoping it would help.

I have been in contact with some network experts and im being told to change my subnet-mask from 255.255.255.0 to 255.255.254.0 to get almost the double available IP addresses.

What will happen if I change my subnet-mask during school hours? Will it disconnect users and will every student have to connect to the wifi again? What about my 3 static printers, will I need to confige network settings?

Thanks for all replies.

Improve this question
1
  • As @vidarlo already answered and implied - yes changing the netmask in the DHCP scope will make more IP's available but that is a change you can't make only in the DHCP server, that also requires changes elsewhere in your network. Also confirm that you 're not already using IP's from a neighbouring range that will become part of the newly extended /23. - Clients still using the /24 netmask won't be able to reach devices that have already received an IP from the extended range and vice-versa so yes you need to update devices with static network settings and make the change outside of workhours
    – HBruijn
    Nov 14 at 12:13

1 Answer 1

Reset to default
3

In such a scenario you'll probably not have much client-to-client communication, so if you start by changing net mask on the router(s) and other servers, and then update net mask in the DHCP scope, you should generally be fine.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .