172.21.19.158 router login
To open the admin panel, type 172.21.19.158 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.
172.21.19.158 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 and password pair is documented for this address, and no vendor is known to ship it as a default gateway, so guessing would be misleading. Check the label printed on the device itself, which commonly carries the default web address and sign-in details, then the product manual or, on equipment supplied by an internet provider, that provider's own support documentation.
How to log in to your router
Type 172.21.19.158 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 172.21.19.158, 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
If the sign-in details are unknown and the label has been removed or overwritten, a factory reset using the recessed button held for roughly ten to thirty seconds restores the defaults. That comes at a cost: custom configuration is erased, including port forwarding, static leases and any changed admin password, and the Wi-Fi network name and key revert to the values on the label, so every connected device must be reconnected.
172.21.19.158 sits inside 172.16.0.0/12, the mid-size private range defined by RFC 1918. That block runs from 172.16.x.x to 172.31.x.x, covers 1,048,576 addresses under the netmask 255.240.0.0, and is never routed on the public internet. It is the range most often seen in mid-size business networks, lab setups, VPN subnets and Docker default bridge networks. It is also the range most often mistaken for public space, because 172 addresses outside the 16-31 second octet are ordinary routable addresses.
Within that block, this address belongs to the 172.21.19.0/24 subnet, whose usable hosts run from 172.21.19.1 to 172.21.19.254 with 172.21.19.255 reserved as the broadcast address. Position 158 is well inside the range typically handed out by DHCP rather than a common gateway position, so anyone arriving here is usually trying to reach a client device, server or container on the local network, or working out which machine on their LAN holds this lease.
Because private addresses are reusable by anyone, no location, operator or organisation can be attached to 172.21.19.158; the same address exists independently on countless separate networks.
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 172.21.19.0/24
The 172.21.19.0/24 subnet runs from 172.21.19.1 to 172.21.19.254, with 172.21.19.255 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.