[Transformer TF300T Android Development] pe1dnn:
Equipment connected to your router or modem get from the router or modem an internal IP number. This is given to the device by the DHCP server in the router or modem.

So when a new device enters your network it is usually configured to use a dynamic IP addres, so for example your TF300T. When the TF300T is swichted on it does not have an address. Instead it broadcasts on the network "I need an address". The DHCP server in the router or modem listens to these broadcasts, and will respond to your TF300T for example: "You can use address 192.168.2.32 for a period of 1 day". So now the TF300T can use that address for one day. It is called a lease. After one day the lease expires. This means that TF300T can not longer use that address and the DHCP server can assign the address to another device. This is useful because when devices come and go you don't want addresses to be used up indefinitely since there are only a limited amount of addresses the DHCP server can assign. This expiration is not a problem, if your TF300T needs to have an address longer it just has to renew the IP address when the lease period is over.

Now for this ROM. This renewal does not seem to work fine all the time. To prevent this problem a longer of even infinite lease period can be used. So instead of the DHCP reply "You can use address 192.168.2.32 for a period of 1 day" the reply is now "You can use address 192.168.2.32 without a time limit". As you can see, this is something the DHCP server tells your TF300T. The DHCP server owns the addresses so this is not something you can set on your TF300T. It is something that shall be set on your router or modem, whichever device acts as DHCP server.

Since this has to be configured in you DHCP server there is no single answer how to do this. This depends on the equipment you have. Sometimes it is not even possible to change any configuration. Sometimes you cannot select an unlimited time but maybe you can set 365 days which is most likely good enough too.

Note that configuring an infinite lease time in the DHCP server may also give problems. If you have a lot of devices that come and go and each device will get an IP address without expiration. For sure you will run out of IP addressed then. For example if you have this in a router in a supermarket offering free WiFi then after about 250 customers used it the address are depleted and the next customers cannot use this service because they will not get an IP address. In this case you need a sensible lease period so the oldest addressed expire freeing it for the next use.

At home it is not a big problem. If after some months you may happen to run out of addresses then you can reboot your router or modem, this will in most cases clean all the leases and when any device reconnects it has to ask for an new IP address anyway.

So look up your router or modem manual how to set the DHCP server lease time (if it is in there, most users will not comprehend what is means anyway so often the user manual does not go into these details). Otherwise ask in a support forum for your router or modem or just look at the menu's if you can find the setting that way.

I hope this answers your question.

This is about the IP lease. A similar story for the WPA key to encrypt your connection. Also this one has a limited life span, not only for reuse but mainly for security. In this case your access point decides the key renewal time. So also this has to be configured in your equipment. So also here this depends on the type and make of the WiFi access point. A longer time however weakens the encryption. There is no free lunch, any configuration change has advantages but also drawbacks.