172.20.72.40 router login
To open the admin panel, type 172.20.72.40 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.
172.20.72.40 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 is recorded for 172.20.72.40. In 172.16.0.0/12 deployments a non-gateway address like this frequently belongs to a virtual machine or a container rather than to a box with a web interface, in which case there is no factory login to find at all.
When there is physical hardware behind the address, its initial credentials are printed on the device label or set out in the model's manual. When the host is virtual, authentication comes from the image, the orchestration platform or the directory service that provisioned it.
How to log in to your router
Type 172.20.72.40 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 172.20.72.40, 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
Access problems on this kind of address are usually solved by looking at the platform rather than the device. Check whether the container or virtual machine is still running, whether the address has been reassigned by the bridge or overlay network, and whether a security group or firewall policy is filtering the management port.
A factory reset only applies to physical equipment, and it removes addressing, credentials and every service setting, meaning the host will not necessarily return to 172.20.72.40 afterwards. For a virtual host the equivalent action is redeploying from an image or snapshot, which discards any state written since it was created.
172.20.72.40 falls in 172.16.0.0/12, the mid-size RFC 1918 block, which uses a 255.240.0.0 netmask and spans 1,048,576 addresses across 172.16.x.x through 172.31.x.x. It is common in mid-size business networks, laboratory environments, VPN subnets and Docker default bridge networking. It is also the block most often misread, because 172.x.x.x addresses outside the 172.16 to 172.31 window are ordinary public space; only this slice is private, and only this slice is unroutable across the internet.
The subnet in question is 172.20.72.0/24, with usable hosts from 172.20.72.1 to 172.20.72.254 and the broadcast address at 172.20.72.255. Host 40 is not a gateway position. In a /12 that has been deliberately subdivided, an address like this typically identifies a workstation, server, virtual machine or container assigned within a planned range. We have records for just one other address in this /24.
Something like 127 searches a year reach this address, usually from an administrator or developer who has encountered it in a container network, a VPN routing table or an application log and wants to confirm it is private space.
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 172.20.72.0/24
The 172.20.72.0/24 subnet runs from 172.20.72.1 to 172.20.72.254, with 172.20.72.255 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.