My brother disabled my internet access for my devices from 10pm - 6am. The internet on his devices still work 24/7. I am still connected to the WiFi but there is no internet access because he did a MAC address time filter. I use my iPhone and my laptop.
Is there any way to get around this?
You can defeat your brother's access restrictions, either by a timing-attack or side-channel attack.
In a timing-attack, you wait for a sufficient time, your brother will remove the MAC filtering for your device.
If you cannot wait for the time-based attack to succeed, you can use a side channel attack and connect to the internet via an alternative channel, such as GSM or a friendly neighbor.
Joke aside, MAC spoofing is a way to overcome MAC filtering. Since MAC-filtering is (usually) only tied to the MAC-address assigned to a network interface controller, you can change your MAC-address to match the one of an unfiltered device. This is a relatively easy process, but can cause harm (Denial of Service), depending on network equipment and configuration.
On wired networks, switches are usually only designed to forward traffic destined MAC-address to one port. If multiple ports have the same MAC-address, the network logs might contain warnings of MAC-flapping and alert the administrator. This blog post demonstrate how the network can become unreliable for devices that share the same MAC-address.
On wireless networks, sharing the same MAC-address usually do not lead to the same problems as on a wired network. The reason for this is that the wireless network is a single network port (a single radio interface) with multiple connected devices. There are no alternative ports for packets to take as long as both devices are connected to the same access point over WiFi.
Sometimes, you also have to clone the IP-address of an unfiltered device (this is also dependent on the network devices that handle MAC-addresses). This can lead to another set of problems:
If possible, try to use statically configure the adapter to use an unused IP-address. If you absolutely have to also spoof the IP-address, wait for the device to disconnect from the network. There is a tool called CPScam that is used to bypass captive portals (which most commonly use MAC-filtering). This tool will monitor the network for active devices, and alert you whenever a device leaves the network. If you impersonate a device that is no longer on the network, it should not cause harm or alarms, at least not until it reconnects.
You could change your MAC address to something different. If he simply blacklisted your MAC addresses, it should be sufficient enough to generate a random address. If he whitelisted his own addresses, you can change your MAC address to that of one of his devices. Note that if there are multiple devices using the same MAC address simultaneously, the involved devices will likely experience connectivity issues.
Changing your MAC address depends on your platform, and I do not think this is possible to do on an iPhone. There is plenty of information out there on how to do this on a desktop or laptop, however.
MAC blocking is not an effective means of censoring internet access if you already have physical access to the router, which is likely since you live in the same home.
There is usually a physical button recessed into the device that you can press with a paperclip to reset it. This will allow you to regain access by resetting it to factory settings. The exact location of this button varies by device.
However, it is important to note that your brother will likely notice that the MAC filters (or other configurations) have been removed, and put them back on and/or bar you from physically accessing the router.
