10.0.21.18 router login
To open the admin panel, type 10.0.21.18 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.
10.0.21.18 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 credentials are recorded for 10.0.21.18, and none should be assumed. The address says nothing about what kind of equipment answers on it. If you need to sign in, read the defaults off the device's own label, look them up in the manual for that specific model number, or ask the ISP or IT team that provisioned it, since managed devices are often shipped with unique per-unit passwords.
How to log in to your router
Type 10.0.21.18 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 10.0.21.18, 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
Recovering access without the password normally means a hardware reset, held with a pin for the interval the manual specifies. Understand the cost first: the device comes back with an empty configuration, so any static addressing, access control lists or service settings must be rebuilt, and the Wi-Fi name and password on wireless models revert to the factory strings on the label.
10.0.21.18 is drawn from 10.0.0.0/8, private address space reserved by RFC 1918 and never routed across the public internet. With a 255.0.0.0 netmask it spans 16,777,216 addresses, which is why it dominates in environments that need room to segment: enterprise and campus networks, ISP-managed home gateways, carrier platforms, VPN address assignment and container networking. In practice it is always broken into far smaller pieces, and at a /24 boundary this address belongs to 10.0.21.0/24, with usable hosts from 10.0.21.1 to 10.0.21.254 and a broadcast address of 10.0.21.255.
Host position 18 is low but not the conventional gateway slot, which most networks put at .1 or occasionally .254. That makes a statically assigned server, printer, access point or appliance a more plausible explanation than a router. Lookups tend to come from someone tracing an unfamiliar device or checking whether an internal service is reachable. This site documents 106 other addresses inside the same /24.
Whois information for 10.0.0.0/8
# 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: 10.0.0.0 - 10.255.255.255
CIDR: 10.0.0.0/8
NetName: PRIVATE-ADDRESS-ABLK-RFC1918-IANA-RESERVED
NetHandle: NET-10-0-0-0-1
Parent: ()
NetType: IANA Special Use
OriginAS:
Organization: Internet Assigned Numbers Authority (IANA)
RegDate: 1995-06-23
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/10.0.0.0
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 10.0.21.0/24
The 10.0.21.0/24 subnet runs from 10.0.21.1 to 10.0.21.254, with 10.0.21.255 reserved as the broadcast address. These are the addresses in it we hold router login details for.
Most looked up in this subnet
All addresses we cover here
107 addresses in this subnet have a page; the most looked-up are listed here.