What other IP addresses can/should I use for my home network?

I've been using 192.168.1.x for my home network, which has been perfectly happy for quite some time. However, I just started a new job, and they use the same set of IP addresses when I connect over the VPN.

Naturally, this causes problems.

What other IP address ranges can (and should) I use to prevent conflicts? Would it be OK to use 192.168.2.x... or 42.x ;) ?

I know at one point my brother had setup our network to use 10.0.0.x - but when I used a traceroute program it would say that all of our packets were going to Brazil or something.

Are there other IP addresses reserved for internal networks that I should use?

You can freely use any Private Network Address within the following reserved ranges:

3. Private Address Space

The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets:

    10.0.0.0        -   10.255.255.255  (10/8 prefix)
    172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
    192.168.0.0     -   192.168.255.255 (192.168/16 prefix)

(from RFC 1918 - Address Allocation for Private Internets)

You'll also want to keep in mind the network Host Address and Broadcast Address:

7. Broadcast IP Addressing - Proposed Standards

If different IP implementations are to be compatible, there must be a distinguished number to denote "all hosts".

Since the local network layer can always map an IP address into data link layer address, the choice of an IP "broadcast host number" is somewhat arbitrary. For simplicity, it should be one not likely to be assigned to a real host. The number whose bits are all ones has this property; this assignment was first proposed in. In the few cases where a host has been assigned an address with a host-number part of all ones, it does not seem onerous to require renumbering.

The address 255.255.255.255 denotes a broadcast on a local hardware network, which must not be forwarded. This address may be used, for example, by hosts that do not know their network number and are asking some server for it.

Thus, a host on net 36, for example, may:

• broadcast to all of its immediate neighbors by using 255.255.255.255

• broadcast to all of net 36 by using 36.255.255.255

(Note that unless the network has been broken up into subnets, these two methods have identical effects.)

If the use of "all ones" in a field of an IP address means "broadcast", using "all zeros" could be viewed as meaning "unspecified". There is probably no reason for such addresses to appear anywhere but as the source address of an ICMP Information Request datagram. However, as a notational convention, we refer to networks (as opposed to hosts) by using addresses with zero fields. For example, 36.0.0.0 means "network number 36" while 36.255.255.255 means "all hosts on network number 36".

(from RFC 919 - Broadcasting Internet Addresses)

Additionally, you'll want to understand Classless Inter-Domain Routing (commonly referred to as CIDR) and its CIDR notation for expressing IP address ranges:

Classless Inter-Domain Routing (CIDR, /ˈsaɪdər/ or /ˈsɪdər/) is a method for allocating IP addresses and IP routing. The Internet Engineering Task Force introduced CIDR in 1993 to replace the previous addressing architecture of classful network design in the Internet. Its goal was to slow the growth of routing tables on routers across the Internet, and to help slow the rapid exhaustion of IPv4 addresses.

CIDR notation is a compact representation of an IP address and its associated routing prefix. The notation is constructed from an IP address, a slash ('/') character, and a decimal number.

The address may denote a single, distinct interface address or the beginning address of an entire network. The maximum size of the network is given by the number of addresses that are possible with the remaining, least-significant bits below the prefix. The aggregation of these bits is often called the host identifier.

For example:

• 192.168.100.14/24 represents the IPv4 address 192.168.100.14 and its associated routing prefix 192.168.100.0, or equivalently, its subnet mask 255.255.255.0, which has 24 leading 1-bits.
• the IPv4 block 192.168.100.0/22 represents the 1024 IPv4 addresses from 192.168.100.0 to 192.168.103.255.
• the IPv6 block 2001:db8::/48 represents the block of IPv6 addresses from 2001:db8:0:0:0:0:0:0 to 2001:db8:0:ffff:ffff:ffff:ffff:ffff.
• ::1/128 represents the IPv6 loopback address. Its prefix length is 128 which is the number of bits in the address.

The 192.168.1.1 IP address used by many home routers is an IANA-reserved private network address or subnet.

What's a subnet? An entire range of IP addresses that you can split up into a smaller ranger (the act of splitting it up is called subnetting) if you want.

So the above range is 192.168.0.0/16. Keeping it simple without getting too much into the individual bits, each "octet" or individual number in the address is 8 bits, and the ones that are "yours" start from the right. So that means the last two octets (16 bits) are yours to do whatever you want. So you can use all the IP addresses from 192.168.0.1 to 192.168.255.254 (the first one is reserved and the last one is a broadcast address) really in any way you want and your router allows.

The simplest route usually taken in this situation is to use the "sub-subnet" 192.168.0.0/24 or 192.168.1.0/24. Using 192.168.0.0/24 as an example, this means your home network can use any IP address from 192.168.0.1 through 192.168.0.254, with 192.168.0.255 being the broadcast address.

But you are free to change the subnet, since you have two numbers that are really "yours", so you can use 192.168.44.0/24 or any other number for the second octet. Just keep in mind that everything that needs to see each other on the network needs to be on the same subnet (i.e. within that subnet's range of IP addresses). So your router's IP address needs to appear in that subnet (good choice is 192.168.44.1), and your router needs to give out DHCP addresses from a range in that subnet (say something like 192.168.44.10 through 192.168.44.50).

Nothing is really stopping you from using 192.168.0.0/16 for your home router either, but it's good practice to leave some room for additional networks or changing things in the future.

Yes, you would be OK using .2.x, and that would not cause any problems, however make sure your netmask is set to 255.255.255.0 and not 255.255.0.0 because it would try to mix your .2.x with your vpn .1.x as if it was the same network.

I know this is an old question, and some answers above are correct.

To put it simply, the Internet Assigned Numbers Authority (IANA) established three blocks of the IP address space for private networks:10.0.0.0 – 10.255.255.255, 172.16.00 – 172.31.255.255, 192.168.0.0 – 192.168.255.255.

The third IP address that you used is enough for most users for connecting up to 254 devices. So it have been commonly used till today.

Note that there is really nothing wrong from using a 10.0.0.0 or 172.16.00.

The reason why you should use private addresses in those ranges in your internal networks, is because these are the addresses that are not used on the internet for real networks.

In fact backbone routers won't forward in general packets for these addresses (although some ISPs actually dish out private IPs to customers, in this case you'll be going through their NAT).

If you choose another range of addresses for your network, which are public addresses, in use somewhere else in the internet, then you lose accessibility to those other addresses, due to local routes to those destinations overriding default routing to the real remote network.