172.21.200.171 router login
To open the admin panel, type 172.21.200.171 into your browser's address bar. If the page does not load, this is probably not the gateway address on your network — see the checks below.
172.21.200.171 router passwords
Where to find them:
- The label on the underside or back of the router — most manufacturers print the default admin username, password and Wi-Fi key there.
- The quick-start card or manual that came in the box.
- Your ISP's account portal, if the device was supplied by them — many set a unique password per line rather than a shared default.
No default username or password is on file for 172.21.200.171, and an address this far up a subnet often belongs to a client with no login page at all. If the device does ask for credentials, its own defaults appear on the product label, in the supplied manual, or in the provisioning documentation for the network.
How to log in to your router
Type 172.21.200.171 into your browser's address bar and press Enter. Type it by hand rather than accepting an autocomplete suggestion, which often fills in a different address you visited before.
If the browser reports that it cannot reach 172.21.200.171, this is not the gateway address on your network. On Windows run ipconfig /all and read the Default Gateway line; on macOS open System Settings, Network, Details, TCP/IP; on Linux run ip route and read the address after "default via".
If the login page loads but rejects your credentials, and you have never changed them, use the defaults printed on the device's label. If they have been changed and nobody knows the new password, a factory reset is the only way back in.
If you do not know the password
Work out which device holds the address before attempting recovery, since high-numbered addresses are commonly leased and move between hosts. On equipment you own, a factory reset restores access at the price of every stored setting; wireless networks it broadcasts revert to the factory name and password on the label, and reconnecting all clients becomes necessary.
Falling between 172.16.0.0 and 172.31.255.255, the address 172.21.200.171 is inside the RFC 1918 block 172.16.0.0/12. That range holds 1,048,576 addresses under a 255.240.0.0 mask and is favoured by mid-size business networks, laboratory environments, VPN subnets and Docker's default bridge networking. It is private throughout, so the number can be reused freely and identifies no organisation. Its /24 is 172.21.200.0, spanning hosts 172.21.200.1 to 172.21.200.254 with broadcast at 172.21.200.255.
At host 171 the address sits high in the subnet, a region frequently given over to dynamic assignment, which makes an ordinary client device the likeliest occupant rather than network infrastructure. A single other address in this /24 has been documented, so there is little public record of the segment. Readers generally reach this page after seeing the address on a device list or in traffic logs and wanting to know what kind of thing it denotes.
Whois information for 172.16.0.0/12
# ARIN WHOIS data and services are subject to the Terms of Use
# available at: https://www.arin.net/resources/registry/whois/tou/
#
# If you see inaccuracies in the results, please report at
# https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
#
# Copyright 1997-2024, American Registry for Internet Numbers, Ltd.
#
NetRange: 172.16.0.0 - 172.31.255.255
CIDR: 172.16.0.0/12
NetName: PRIVATE-ADDRESS-BBLK-RFC1918-IANA-RESERVED
NetHandle: NET-172-16-0-0-1
Parent: ()
NetType: IANA Special Use
OriginAS:
Organization: Internet Assigned Numbers Authority (IANA)
RegDate: 1994-03-15
Updated: 2013-08-30
Comment: These addresses are in use by many millions of independently operated networks, which might be as small as a single computer connected to a home gateway, and are automatically configured in hundreds of millions of devices. They are only intended for use within a private context and traffic that needs to cross the Internet will need to use a different, unique address.
Comment:
Comment: These addresses can be used by anyone without any need to coordinate with IANA or an Internet registry. The traffic from these addresses does not come from ICANN or IANA. We are not the source of activity you may see on logs or in e-mail records. Please refer to http://www.iana.org/abuse/answers
Comment:
Comment: These addresses were assigned by the IETF, the organization that develops Internet protocols, in the Best Current Practice document, RFC 1918 which can be found at:
Comment: http://datatracker.ietf.org/doc/rfc1918
Ref: https://rdap.arin.net/registry/ip/172.16.0.0
OrgName: Internet Assigned Numbers Authority
OrgId: IANA
Address: 12025 Waterfront Drive
Address: Suite 300
City: Los Angeles
StateProv: CA
PostalCode: 90094
Country: US
RegDate:
Updated: 2012-08-31
Ref: https://rdap.arin.net/registry/entity/IANA
OrgAbuseHandle: IANA-IP-ARIN
OrgAbuseName: ICANN
OrgAbusePhone: +1-310-301-5820
OrgAbuseEmail: abuse@iana.org
OrgAbuseRef: https://rdap.arin.net/registry/entity/IANA-IP-ARIN
OrgTechHandle: IANA-IP-ARIN
OrgTechName: ICANN
OrgTechPhone: +1-310-301-5820
OrgTechEmail: abuse@iana.org
OrgTechRef: https://rdap.arin.net/registry/entity/IANA-IP-ARIN
Other documented addresses in 172.21.200.0/24
The 172.21.200.0/24 subnet runs from 172.21.200.1 to 172.21.200.254, with 172.21.200.255 reserved as the broadcast address. These are the addresses in it we hold router login details for.
All addresses we cover here
2 addresses in this subnet have a page; the most looked-up are listed here.