Speed and call quality testMy IP addressIP subnet calculatorDNS reportWhoIs lookupRemote support

Internet and network

Speed and call quality testTest delay, jitter and speed, with a focus on phone calls.My IP addressYour public IPv4 and IPv6 addresses, provider and address range.WhoIs lookupWho owns a domain or IP address, when it expires, and its DNS.DNS reportEvery DNS record for a domain, with email setup checked.IP subnet calculatorWork out a network's range, mask and hosts, and split it into subnets.

Computers and devices

Update checkIs this computer, phone and browser up to date? With links to update.Camera and mic testCheck your webcam and microphone before a call.Test print pagePrint an A4 page to check a printer: edges, text, line art and colours.

Make and print

Clean textStrip hidden characters, smart quotes and odd spaces from pasted text.QR code makerMake a QR code for a link, contact or message. Nothing leaves your browser.Wi-Fi QR posterPrint an A4 poster that lets guests join your Wi-Fi by scanning.

Surftec support

Remote supportLet a Surftec engineer connect to your computer to help you.All workingA full-screen confirmation that everything is up and running.

Surftec

Surftec websiteServices, news and how to contact Surftec
Cloud Tools
Guest
GuestNot signed in

Surftec customers will be recognised automatically when they use these tools from their office network.

Customer sign-in is coming soon.

IP subnet calculator

Type an address with its prefix or mask to see the network, its usable range and masks. Split it into smaller subnets, or look up any prefix in the reference tables.

Network84.167.0.0/16
Usable hosts65,534
Subnet mask255.255.0.0
Addresses65,536
Network address
84.167.0.0
Broadcast address
84.167.255.255
First usable
84.167.0.1
Last usable
84.167.255.254
Usable hosts
65,534 (65,536 less the network and broadcast addresses)
Subnet mask
255.255.0.0
Wildcard mask
0.0.255.255 (Cisco ACLs, OSPF)
Prefix length
/16
Type
Public public
Old class
A (default /8)
As numbers
Hex 54A70000 · Integer 1420230656 to 1420296191
Reverse DNS zone
167.84.in-addr.arpa
Binary
Binary view
Binary (network bits bold, host bits grey)Dotted
Address01010100.10100111..00000000.0000000084.167.0.0
Subnet mask11111111.11111111..00000000.00000000255.255.0.0
Network01010100.10100111..00000000.0000000084.167.0.0
Broadcast01010100.10100111..11111111.1111111184.167.255.255
Split into smaller subnets/28
/17 (2)/18 (4)/19 (8)/20 (16)/21 (32)/22 (64)/23 (128)/24 (256)/25 (512)/26 (1,024)/27 (2,048)/28 (4,096)

84.167.0.0/16 makes 4,096 subnets of /28; the first 256 are listed.

Subnets
#SubnetUsable hosts rangeBroadcastHosts
184.167.0.0/2884.167.0.1 to 84.167.0.1484.167.0.1514
284.167.0.16/2884.167.0.17 to 84.167.0.3084.167.0.3114
384.167.0.32/2884.167.0.33 to 84.167.0.4684.167.0.4714
484.167.0.48/2884.167.0.49 to 84.167.0.6284.167.0.6314
584.167.0.64/2884.167.0.65 to 84.167.0.7884.167.0.7914
684.167.0.80/2884.167.0.81 to 84.167.0.9484.167.0.9514
784.167.0.96/2884.167.0.97 to 84.167.0.11084.167.0.11114
884.167.0.112/2884.167.0.113 to 84.167.0.12684.167.0.12714
984.167.0.128/2884.167.0.129 to 84.167.0.14284.167.0.14314
1084.167.0.144/2884.167.0.145 to 84.167.0.15884.167.0.15914
1184.167.0.160/2884.167.0.161 to 84.167.0.17484.167.0.17514
1284.167.0.176/2884.167.0.177 to 84.167.0.19084.167.0.19114
1384.167.0.192/2884.167.0.193 to 84.167.0.20684.167.0.20714
1484.167.0.208/2884.167.0.209 to 84.167.0.22284.167.0.22314
1584.167.0.224/2884.167.0.225 to 84.167.0.23884.167.0.23914
1684.167.0.240/2884.167.0.241 to 84.167.0.25484.167.0.25514
1784.167.1.0/2884.167.1.1 to 84.167.1.1484.167.1.1514
1884.167.1.16/2884.167.1.17 to 84.167.1.3084.167.1.3114
1984.167.1.32/2884.167.1.33 to 84.167.1.4684.167.1.4714
2084.167.1.48/2884.167.1.49 to 84.167.1.6284.167.1.6314
2184.167.1.64/2884.167.1.65 to 84.167.1.7884.167.1.7914
2284.167.1.80/2884.167.1.81 to 84.167.1.9484.167.1.9514
2384.167.1.96/2884.167.1.97 to 84.167.1.11084.167.1.11114
2484.167.1.112/2884.167.1.113 to 84.167.1.12684.167.1.12714
2584.167.1.128/2884.167.1.129 to 84.167.1.14284.167.1.14314
2684.167.1.144/2884.167.1.145 to 84.167.1.15884.167.1.15914
2784.167.1.160/2884.167.1.161 to 84.167.1.17484.167.1.17514
2884.167.1.176/2884.167.1.177 to 84.167.1.19084.167.1.19114
2984.167.1.192/2884.167.1.193 to 84.167.1.20684.167.1.20714
3084.167.1.208/2884.167.1.209 to 84.167.1.22284.167.1.22314
3184.167.1.224/2884.167.1.225 to 84.167.1.23884.167.1.23914
3284.167.1.240/2884.167.1.241 to 84.167.1.25484.167.1.25514
3384.167.2.0/2884.167.2.1 to 84.167.2.1484.167.2.1514
3484.167.2.16/2884.167.2.17 to 84.167.2.3084.167.2.3114
3584.167.2.32/2884.167.2.33 to 84.167.2.4684.167.2.4714
3684.167.2.48/2884.167.2.49 to 84.167.2.6284.167.2.6314
3784.167.2.64/2884.167.2.65 to 84.167.2.7884.167.2.7914
3884.167.2.80/2884.167.2.81 to 84.167.2.9484.167.2.9514
3984.167.2.96/2884.167.2.97 to 84.167.2.11084.167.2.11114
4084.167.2.112/2884.167.2.113 to 84.167.2.12684.167.2.12714
4184.167.2.128/2884.167.2.129 to 84.167.2.14284.167.2.14314
4284.167.2.144/2884.167.2.145 to 84.167.2.15884.167.2.15914
4384.167.2.160/2884.167.2.161 to 84.167.2.17484.167.2.17514
4484.167.2.176/2884.167.2.177 to 84.167.2.19084.167.2.19114
4584.167.2.192/2884.167.2.193 to 84.167.2.20684.167.2.20714
4684.167.2.208/2884.167.2.209 to 84.167.2.22284.167.2.22314
4784.167.2.224/2884.167.2.225 to 84.167.2.23884.167.2.23914
4884.167.2.240/2884.167.2.241 to 84.167.2.25484.167.2.25514
4984.167.3.0/2884.167.3.1 to 84.167.3.1484.167.3.1514
5084.167.3.16/2884.167.3.17 to 84.167.3.3084.167.3.3114
5184.167.3.32/2884.167.3.33 to 84.167.3.4684.167.3.4714
5284.167.3.48/2884.167.3.49 to 84.167.3.6284.167.3.6314
5384.167.3.64/2884.167.3.65 to 84.167.3.7884.167.3.7914
5484.167.3.80/2884.167.3.81 to 84.167.3.9484.167.3.9514
5584.167.3.96/2884.167.3.97 to 84.167.3.11084.167.3.11114
5684.167.3.112/2884.167.3.113 to 84.167.3.12684.167.3.12714
5784.167.3.128/2884.167.3.129 to 84.167.3.14284.167.3.14314
5884.167.3.144/2884.167.3.145 to 84.167.3.15884.167.3.15914
5984.167.3.160/2884.167.3.161 to 84.167.3.17484.167.3.17514
6084.167.3.176/2884.167.3.177 to 84.167.3.19084.167.3.19114
6184.167.3.192/2884.167.3.193 to 84.167.3.20684.167.3.20714
6284.167.3.208/2884.167.3.209 to 84.167.3.22284.167.3.22314
6384.167.3.224/2884.167.3.225 to 84.167.3.23884.167.3.23914
6484.167.3.240/2884.167.3.241 to 84.167.3.25484.167.3.25514
6584.167.4.0/2884.167.4.1 to 84.167.4.1484.167.4.1514
6684.167.4.16/2884.167.4.17 to 84.167.4.3084.167.4.3114
6784.167.4.32/2884.167.4.33 to 84.167.4.4684.167.4.4714
6884.167.4.48/2884.167.4.49 to 84.167.4.6284.167.4.6314
6984.167.4.64/2884.167.4.65 to 84.167.4.7884.167.4.7914
7084.167.4.80/2884.167.4.81 to 84.167.4.9484.167.4.9514
7184.167.4.96/2884.167.4.97 to 84.167.4.11084.167.4.11114
7284.167.4.112/2884.167.4.113 to 84.167.4.12684.167.4.12714
7384.167.4.128/2884.167.4.129 to 84.167.4.14284.167.4.14314
7484.167.4.144/2884.167.4.145 to 84.167.4.15884.167.4.15914
7584.167.4.160/2884.167.4.161 to 84.167.4.17484.167.4.17514
7684.167.4.176/2884.167.4.177 to 84.167.4.19084.167.4.19114
7784.167.4.192/2884.167.4.193 to 84.167.4.20684.167.4.20714
7884.167.4.208/2884.167.4.209 to 84.167.4.22284.167.4.22314
7984.167.4.224/2884.167.4.225 to 84.167.4.23884.167.4.23914
8084.167.4.240/2884.167.4.241 to 84.167.4.25484.167.4.25514
8184.167.5.0/2884.167.5.1 to 84.167.5.1484.167.5.1514
8284.167.5.16/2884.167.5.17 to 84.167.5.3084.167.5.3114
8384.167.5.32/2884.167.5.33 to 84.167.5.4684.167.5.4714
8484.167.5.48/2884.167.5.49 to 84.167.5.6284.167.5.6314
8584.167.5.64/2884.167.5.65 to 84.167.5.7884.167.5.7914
8684.167.5.80/2884.167.5.81 to 84.167.5.9484.167.5.9514
8784.167.5.96/2884.167.5.97 to 84.167.5.11084.167.5.11114
8884.167.5.112/2884.167.5.113 to 84.167.5.12684.167.5.12714
8984.167.5.128/2884.167.5.129 to 84.167.5.14284.167.5.14314
9084.167.5.144/2884.167.5.145 to 84.167.5.15884.167.5.15914
9184.167.5.160/2884.167.5.161 to 84.167.5.17484.167.5.17514
9284.167.5.176/2884.167.5.177 to 84.167.5.19084.167.5.19114
9384.167.5.192/2884.167.5.193 to 84.167.5.20684.167.5.20714
9484.167.5.208/2884.167.5.209 to 84.167.5.22284.167.5.22314
9584.167.5.224/2884.167.5.225 to 84.167.5.23884.167.5.23914
9684.167.5.240/2884.167.5.241 to 84.167.5.25484.167.5.25514
9784.167.6.0/2884.167.6.1 to 84.167.6.1484.167.6.1514
9884.167.6.16/2884.167.6.17 to 84.167.6.3084.167.6.3114
9984.167.6.32/2884.167.6.33 to 84.167.6.4684.167.6.4714
10084.167.6.48/2884.167.6.49 to 84.167.6.6284.167.6.6314
10184.167.6.64/2884.167.6.65 to 84.167.6.7884.167.6.7914
10284.167.6.80/2884.167.6.81 to 84.167.6.9484.167.6.9514
10384.167.6.96/2884.167.6.97 to 84.167.6.11084.167.6.11114
10484.167.6.112/2884.167.6.113 to 84.167.6.12684.167.6.12714
10584.167.6.128/2884.167.6.129 to 84.167.6.14284.167.6.14314
10684.167.6.144/2884.167.6.145 to 84.167.6.15884.167.6.15914
10784.167.6.160/2884.167.6.161 to 84.167.6.17484.167.6.17514
10884.167.6.176/2884.167.6.177 to 84.167.6.19084.167.6.19114
10984.167.6.192/2884.167.6.193 to 84.167.6.20684.167.6.20714
11084.167.6.208/2884.167.6.209 to 84.167.6.22284.167.6.22314
11184.167.6.224/2884.167.6.225 to 84.167.6.23884.167.6.23914
11284.167.6.240/2884.167.6.241 to 84.167.6.25484.167.6.25514
11384.167.7.0/2884.167.7.1 to 84.167.7.1484.167.7.1514
11484.167.7.16/2884.167.7.17 to 84.167.7.3084.167.7.3114
11584.167.7.32/2884.167.7.33 to 84.167.7.4684.167.7.4714
11684.167.7.48/2884.167.7.49 to 84.167.7.6284.167.7.6314
11784.167.7.64/2884.167.7.65 to 84.167.7.7884.167.7.7914
11884.167.7.80/2884.167.7.81 to 84.167.7.9484.167.7.9514
11984.167.7.96/2884.167.7.97 to 84.167.7.11084.167.7.11114
12084.167.7.112/2884.167.7.113 to 84.167.7.12684.167.7.12714
12184.167.7.128/2884.167.7.129 to 84.167.7.14284.167.7.14314
12284.167.7.144/2884.167.7.145 to 84.167.7.15884.167.7.15914
12384.167.7.160/2884.167.7.161 to 84.167.7.17484.167.7.17514
12484.167.7.176/2884.167.7.177 to 84.167.7.19084.167.7.19114
12584.167.7.192/2884.167.7.193 to 84.167.7.20684.167.7.20714
12684.167.7.208/2884.167.7.209 to 84.167.7.22284.167.7.22314
12784.167.7.224/2884.167.7.225 to 84.167.7.23884.167.7.23914
12884.167.7.240/2884.167.7.241 to 84.167.7.25484.167.7.25514
12984.167.8.0/2884.167.8.1 to 84.167.8.1484.167.8.1514
13084.167.8.16/2884.167.8.17 to 84.167.8.3084.167.8.3114
13184.167.8.32/2884.167.8.33 to 84.167.8.4684.167.8.4714
13284.167.8.48/2884.167.8.49 to 84.167.8.6284.167.8.6314
13384.167.8.64/2884.167.8.65 to 84.167.8.7884.167.8.7914
13484.167.8.80/2884.167.8.81 to 84.167.8.9484.167.8.9514
13584.167.8.96/2884.167.8.97 to 84.167.8.11084.167.8.11114
13684.167.8.112/2884.167.8.113 to 84.167.8.12684.167.8.12714
13784.167.8.128/2884.167.8.129 to 84.167.8.14284.167.8.14314
13884.167.8.144/2884.167.8.145 to 84.167.8.15884.167.8.15914
13984.167.8.160/2884.167.8.161 to 84.167.8.17484.167.8.17514
14084.167.8.176/2884.167.8.177 to 84.167.8.19084.167.8.19114
14184.167.8.192/2884.167.8.193 to 84.167.8.20684.167.8.20714
14284.167.8.208/2884.167.8.209 to 84.167.8.22284.167.8.22314
14384.167.8.224/2884.167.8.225 to 84.167.8.23884.167.8.23914
14484.167.8.240/2884.167.8.241 to 84.167.8.25484.167.8.25514
14584.167.9.0/2884.167.9.1 to 84.167.9.1484.167.9.1514
14684.167.9.16/2884.167.9.17 to 84.167.9.3084.167.9.3114
14784.167.9.32/2884.167.9.33 to 84.167.9.4684.167.9.4714
14884.167.9.48/2884.167.9.49 to 84.167.9.6284.167.9.6314
14984.167.9.64/2884.167.9.65 to 84.167.9.7884.167.9.7914
15084.167.9.80/2884.167.9.81 to 84.167.9.9484.167.9.9514
15184.167.9.96/2884.167.9.97 to 84.167.9.11084.167.9.11114
15284.167.9.112/2884.167.9.113 to 84.167.9.12684.167.9.12714
15384.167.9.128/2884.167.9.129 to 84.167.9.14284.167.9.14314
15484.167.9.144/2884.167.9.145 to 84.167.9.15884.167.9.15914
15584.167.9.160/2884.167.9.161 to 84.167.9.17484.167.9.17514
15684.167.9.176/2884.167.9.177 to 84.167.9.19084.167.9.19114
15784.167.9.192/2884.167.9.193 to 84.167.9.20684.167.9.20714
15884.167.9.208/2884.167.9.209 to 84.167.9.22284.167.9.22314
15984.167.9.224/2884.167.9.225 to 84.167.9.23884.167.9.23914
16084.167.9.240/2884.167.9.241 to 84.167.9.25484.167.9.25514
16184.167.10.0/2884.167.10.1 to 84.167.10.1484.167.10.1514
16284.167.10.16/2884.167.10.17 to 84.167.10.3084.167.10.3114
16384.167.10.32/2884.167.10.33 to 84.167.10.4684.167.10.4714
16484.167.10.48/2884.167.10.49 to 84.167.10.6284.167.10.6314
16584.167.10.64/2884.167.10.65 to 84.167.10.7884.167.10.7914
16684.167.10.80/2884.167.10.81 to 84.167.10.9484.167.10.9514
16784.167.10.96/2884.167.10.97 to 84.167.10.11084.167.10.11114
16884.167.10.112/2884.167.10.113 to 84.167.10.12684.167.10.12714
16984.167.10.128/2884.167.10.129 to 84.167.10.14284.167.10.14314
17084.167.10.144/2884.167.10.145 to 84.167.10.15884.167.10.15914
17184.167.10.160/2884.167.10.161 to 84.167.10.17484.167.10.17514
17284.167.10.176/2884.167.10.177 to 84.167.10.19084.167.10.19114
17384.167.10.192/2884.167.10.193 to 84.167.10.20684.167.10.20714
17484.167.10.208/2884.167.10.209 to 84.167.10.22284.167.10.22314
17584.167.10.224/2884.167.10.225 to 84.167.10.23884.167.10.23914
17684.167.10.240/2884.167.10.241 to 84.167.10.25484.167.10.25514
17784.167.11.0/2884.167.11.1 to 84.167.11.1484.167.11.1514
17884.167.11.16/2884.167.11.17 to 84.167.11.3084.167.11.3114
17984.167.11.32/2884.167.11.33 to 84.167.11.4684.167.11.4714
18084.167.11.48/2884.167.11.49 to 84.167.11.6284.167.11.6314
18184.167.11.64/2884.167.11.65 to 84.167.11.7884.167.11.7914
18284.167.11.80/2884.167.11.81 to 84.167.11.9484.167.11.9514
18384.167.11.96/2884.167.11.97 to 84.167.11.11084.167.11.11114
18484.167.11.112/2884.167.11.113 to 84.167.11.12684.167.11.12714
18584.167.11.128/2884.167.11.129 to 84.167.11.14284.167.11.14314
18684.167.11.144/2884.167.11.145 to 84.167.11.15884.167.11.15914
18784.167.11.160/2884.167.11.161 to 84.167.11.17484.167.11.17514
18884.167.11.176/2884.167.11.177 to 84.167.11.19084.167.11.19114
18984.167.11.192/2884.167.11.193 to 84.167.11.20684.167.11.20714
19084.167.11.208/2884.167.11.209 to 84.167.11.22284.167.11.22314
19184.167.11.224/2884.167.11.225 to 84.167.11.23884.167.11.23914
19284.167.11.240/2884.167.11.241 to 84.167.11.25484.167.11.25514
19384.167.12.0/2884.167.12.1 to 84.167.12.1484.167.12.1514
19484.167.12.16/2884.167.12.17 to 84.167.12.3084.167.12.3114
19584.167.12.32/2884.167.12.33 to 84.167.12.4684.167.12.4714
19684.167.12.48/2884.167.12.49 to 84.167.12.6284.167.12.6314
19784.167.12.64/2884.167.12.65 to 84.167.12.7884.167.12.7914
19884.167.12.80/2884.167.12.81 to 84.167.12.9484.167.12.9514
19984.167.12.96/2884.167.12.97 to 84.167.12.11084.167.12.11114
20084.167.12.112/2884.167.12.113 to 84.167.12.12684.167.12.12714
20184.167.12.128/2884.167.12.129 to 84.167.12.14284.167.12.14314
20284.167.12.144/2884.167.12.145 to 84.167.12.15884.167.12.15914
20384.167.12.160/2884.167.12.161 to 84.167.12.17484.167.12.17514
20484.167.12.176/2884.167.12.177 to 84.167.12.19084.167.12.19114
20584.167.12.192/2884.167.12.193 to 84.167.12.20684.167.12.20714
20684.167.12.208/2884.167.12.209 to 84.167.12.22284.167.12.22314
20784.167.12.224/2884.167.12.225 to 84.167.12.23884.167.12.23914
20884.167.12.240/2884.167.12.241 to 84.167.12.25484.167.12.25514
20984.167.13.0/2884.167.13.1 to 84.167.13.1484.167.13.1514
21084.167.13.16/2884.167.13.17 to 84.167.13.3084.167.13.3114
21184.167.13.32/2884.167.13.33 to 84.167.13.4684.167.13.4714
21284.167.13.48/2884.167.13.49 to 84.167.13.6284.167.13.6314
21384.167.13.64/2884.167.13.65 to 84.167.13.7884.167.13.7914
21484.167.13.80/2884.167.13.81 to 84.167.13.9484.167.13.9514
21584.167.13.96/2884.167.13.97 to 84.167.13.11084.167.13.11114
21684.167.13.112/2884.167.13.113 to 84.167.13.12684.167.13.12714
21784.167.13.128/2884.167.13.129 to 84.167.13.14284.167.13.14314
21884.167.13.144/2884.167.13.145 to 84.167.13.15884.167.13.15914
21984.167.13.160/2884.167.13.161 to 84.167.13.17484.167.13.17514
22084.167.13.176/2884.167.13.177 to 84.167.13.19084.167.13.19114
22184.167.13.192/2884.167.13.193 to 84.167.13.20684.167.13.20714
22284.167.13.208/2884.167.13.209 to 84.167.13.22284.167.13.22314
22384.167.13.224/2884.167.13.225 to 84.167.13.23884.167.13.23914
22484.167.13.240/2884.167.13.241 to 84.167.13.25484.167.13.25514
22584.167.14.0/2884.167.14.1 to 84.167.14.1484.167.14.1514
22684.167.14.16/2884.167.14.17 to 84.167.14.3084.167.14.3114
22784.167.14.32/2884.167.14.33 to 84.167.14.4684.167.14.4714
22884.167.14.48/2884.167.14.49 to 84.167.14.6284.167.14.6314
22984.167.14.64/2884.167.14.65 to 84.167.14.7884.167.14.7914
23084.167.14.80/2884.167.14.81 to 84.167.14.9484.167.14.9514
23184.167.14.96/2884.167.14.97 to 84.167.14.11084.167.14.11114
23284.167.14.112/2884.167.14.113 to 84.167.14.12684.167.14.12714
23384.167.14.128/2884.167.14.129 to 84.167.14.14284.167.14.14314
23484.167.14.144/2884.167.14.145 to 84.167.14.15884.167.14.15914
23584.167.14.160/2884.167.14.161 to 84.167.14.17484.167.14.17514
23684.167.14.176/2884.167.14.177 to 84.167.14.19084.167.14.19114
23784.167.14.192/2884.167.14.193 to 84.167.14.20684.167.14.20714
23884.167.14.208/2884.167.14.209 to 84.167.14.22284.167.14.22314
23984.167.14.224/2884.167.14.225 to 84.167.14.23884.167.14.23914
24084.167.14.240/2884.167.14.241 to 84.167.14.25484.167.14.25514
24184.167.15.0/2884.167.15.1 to 84.167.15.1484.167.15.1514
24284.167.15.16/2884.167.15.17 to 84.167.15.3084.167.15.3114
24384.167.15.32/2884.167.15.33 to 84.167.15.4684.167.15.4714
24484.167.15.48/2884.167.15.49 to 84.167.15.6284.167.15.6314
24584.167.15.64/2884.167.15.65 to 84.167.15.7884.167.15.7914
24684.167.15.80/2884.167.15.81 to 84.167.15.9484.167.15.9514
24784.167.15.96/2884.167.15.97 to 84.167.15.11084.167.15.11114
24884.167.15.112/2884.167.15.113 to 84.167.15.12684.167.15.12714
24984.167.15.128/2884.167.15.129 to 84.167.15.14284.167.15.14314
25084.167.15.144/2884.167.15.145 to 84.167.15.15884.167.15.15914
25184.167.15.160/2884.167.15.161 to 84.167.15.17484.167.15.17514
25284.167.15.176/2884.167.15.177 to 84.167.15.19084.167.15.19114
25384.167.15.192/2884.167.15.193 to 84.167.15.20684.167.15.20714
25484.167.15.208/2884.167.15.209 to 84.167.15.22284.167.15.22314
25584.167.15.224/2884.167.15.225 to 84.167.15.23884.167.15.23914
25684.167.15.240/2884.167.15.241 to 84.167.15.25484.167.15.25514

IPv4 CIDR reference (/0 to /32)

IPv4 prefix lengths
PrefixSubnet maskWildcardAddressesUsable hostsSizeTypical use
/00.0.0.0255.255.255.2554,294,967,2964,294,967,29416,777,216 × /24
/1128.0.0.0127.255.255.2552,147,483,6482,147,483,6468,388,608 × /24
/2192.0.0.063.255.255.2551,073,741,8241,073,741,8224,194,304 × /24
/3224.0.0.031.255.255.255536,870,912536,870,9102,097,152 × /24
/4240.0.0.015.255.255.255268,435,456268,435,4541,048,576 × /24
/5248.0.0.07.255.255.255134,217,728134,217,726524,288 × /24
/6252.0.0.03.255.255.25567,108,86467,108,862262,144 × /24
/7254.0.0.01.255.255.25533,554,43233,554,430131,072 × /24
/8255.0.0.00.255.255.25516,777,21616,777,21465,536 × /24Old class A; 10.0.0.0/8
/9255.128.0.00.127.255.2558,388,6088,388,60632,768 × /24
/10255.192.0.00.63.255.2554,194,3044,194,30216,384 × /24
/11255.224.0.00.31.255.2552,097,1522,097,1508,192 × /24
/12255.240.0.00.15.255.2551,048,5761,048,5744,096 × /24172.16.0.0/12
/13255.248.0.00.7.255.255524,288524,2862,048 × /24
/14255.252.0.00.3.255.255262,144262,1421,024 × /24
/15255.254.0.00.1.255.255131,072131,070512 × /24
/16255.255.0.00.0.255.25565,53665,534256 × /24Old class B; 192.168.0.0/16
/17255.255.128.00.0.127.25532,76832,766128 × /24
/18255.255.192.00.0.63.25516,38416,38264 × /24
/19255.255.224.00.0.31.2558,1928,19032 × /24
/20255.255.240.00.0.15.2554,0964,09416 × /24
/21255.255.248.00.0.7.2552,0482,0468 × /24
/22255.255.252.00.0.3.2551,0241,0224 × /24Large office or guest Wi-Fi (1,022 hosts)
/23255.255.254.00.0.1.2555125102 × /24Larger office LAN (510 hosts)
/24255.255.255.00.0.0.2552562541 × /24Typical office LAN (old class C)
/25255.255.255.1280.0.0.1271281261/2 of a /24Smaller LAN or VLAN
/26255.255.255.1920.0.0.6364621/4 of a /24Smaller LAN or VLAN
/27255.255.255.2240.0.0.3132301/8 of a /24Small VLAN, phones, cameras
/28255.255.255.2400.0.0.1516141/16 of a /24Small VLAN, phones, cameras
/29255.255.255.2480.0.0.7861/32 of a /24Small fixed public block (5 usable)
/30255.255.255.2520.0.0.3421/64 of a /24Point-to-point (old style)
/31255.255.255.2540.0.0.1221/128 of a /24Point-to-point link (RFC 3021)
/32255.255.255.2550.0.0.0111/256 of a /24One host

IPv6 prefix reference

IPv6 prefix lengths
PrefixAddresses/64 LANs/48 sitesNibbleTypical use
/342,535,295,865,117,307,932,921,825,928,971,026,432 (2^125)2,305,843,009,213,693,95235,184,372,088,832NoAll global unicast (2000::/3)
/165,192,296,858,534,827,628,530,496,329,220,096 (2^112)281,474,976,710,6564,294,967,296Yes
/20324,518,553,658,426,726,783,156,020,576,256 (2^108)17,592,186,044,416268,435,456YesLarge provider allocation (RIPE minimum for some)
/29633,825,300,114,114,700,748,351,602,688 (2^99)34,359,738,368524,288NoRIPE allocation to a provider (often)
/3279,228,162,514,264,337,593,543,950,336 (2^96)4,294,967,29665,536YesProvider allocation (RIPE default)
/364,951,760,157,141,521,099,596,496,896 (2^92)268,435,4564,096Yes
/40309,485,009,821,345,068,724,781,056 (2^88)16,777,216256Yes
/4419,342,813,113,834,066,795,298,816 (2^84)1,048,57616Yes
/481,208,925,819,614,629,174,706,176 (2^80)65,5361YesOne site or organisation (RIPE PI / assignment)
/5275,557,863,725,914,323,419,136 (2^76)4,096Yes
/564,722,366,482,869,645,213,696 (2^72)256YesSmall site or home (common provider assignment)
/60295,147,905,179,352,825,856 (2^68)16YesSome home broadband (16 LANs)
/6418,446,744,073,709,551,616 (2^64)1YesOne LAN or VLAN (needed for SLAAC)
/7272,057,594,037,927,936 (2^56)1/256 of a /64Yes
/80281,474,976,710,656 (2^48)1/65,536 of a /64Yes
/964,294,967,2961/4,294,967,296 of a /64YesEmbeds an IPv4 address (NAT64)
/11265,5361/281,474,976,710,656 of a /64Yes
/1202561/72,057,594,037,927,936 of a /64Yes
/124161/1,152,921,504,606,846,976 of a /64Yes
/12641/4,611,686,018,427,387,904 of a /64No
/12721/9,223,372,036,854,775,808 of a /64NoPoint-to-point link (RFC 6164)
/12811/18,446,744,073,709,551,616 of a /64YesOne host or loopback

Private and special ranges

IPv4

Special-purpose ranges
RangeNameWhat it is
255.255.255.255/32Limited broadcastEvery host on the local network
0.0.0.0/8This networkNot routed; 0.0.0.0 means "any address" in settings
10.0.0.0/8Private (RFC 1918)Office and home networks; not routed on the internet
100.64.0.0/10Shared address space (CGNAT)Used by providers behind carrier-grade NAT (RFC 6598)
127.0.0.0/8LoopbackThis computer
169.254.0.0/16Link-local (APIPA)Self-assigned when no DHCP server answers
172.16.0.0/12Private (RFC 1918)Office and home networks; not routed on the internet
192.0.0.0/24IETF protocol assignmentsSpecial uses such as DS-Lite
192.0.2.0/24Documentation (TEST-NET-1)For examples; never used on a network
192.88.99.0/246to4 relay (deprecated)Formerly anycast for 6to4
192.168.0.0/16Private (RFC 1918)Office and home networks; not routed on the internet
198.18.0.0/15BenchmarkingNetwork equipment testing (RFC 2544)
198.51.100.0/24Documentation (TEST-NET-2)For examples; never used on a network
203.0.113.0/24Documentation (TEST-NET-3)For examples; never used on a network
224.0.0.0/4MulticastOne-to-many traffic, such as IPTV and routing protocols
240.0.0.0/4ReservedFuture use; not usable on most systems

IPv6

Special-purpose ranges
RangeNameWhat it is
::/128UnspecifiedNo address; :: means "any address" in settings
::1/128LoopbackThis computer
::ffff:0:0/96IPv4-mappedAn IPv4 address written as IPv6
64:ff9b::/96NAT64IPv4 addresses reached through a NAT64 gateway
100::/64Discard onlyTraffic sent here is dropped (RFC 6666)
2001:db8::/32DocumentationFor examples; never used on a network
2001::/32TeredoIPv6 tunnelled over IPv4 UDP
2002::/166to4IPv6 tunnelled over IPv4 (largely retired)
3fff::/20DocumentationFor examples (RFC 9637)
fc00::/7Unique local (ULA)Private IPv6, like RFC 1918; usually fd00::/8
fe80::/10Link-localEvery IPv6 interface has one; not routed
ff00::/8MulticastOne-to-many traffic; replaces broadcast
2000::/3Global unicastPublic internet addresses

About this tool

A network is written as an address and a prefix length, such as 192.168.1.0/24: the first 24 bits name the network and the rest number the devices on it. The calculator works out where the network starts and ends, how many devices it holds, its subnet and wildcard masks, and the reverse DNS zone to ask your provider for.

It also splits a network into equal smaller ones (one per VLAN or site), turns a range of addresses into the fewest CIDR blocks for a firewall rule, and lists every IPv4 prefix length and the common IPv6 ones in reference tables.

Common questions

Why are two addresses lost in every IPv4 subnet?

The first address names the network and the last is the broadcast address, so a /24 has 256 addresses but 254 for devices. A /31 (a link between two routers) and a /32 (one host) are the exceptions.

What size of IPv6 network should a LAN use?

Always /64. Devices pick their own address within it (SLAAC), which needs the full 64 bits. A site usually gets a /48 or /56 from its provider, which holds 65,536 or 256 LANs.

What is a wildcard mask?

The subnet mask turned inside out: 255.255.255.0 becomes 0.0.0.255. Cisco access lists and OSPF use it to say which bits must match.

Which ranges can I use inside an office?

IPv4: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. IPv6: unique local addresses from fd00::/8, though most networks use the public prefix from their provider.