My PC Has an IP Address from 169.254 ...

[Bulldog]

As with many home LANs, my router assigns IP addresses (via DHCP) from the range 192.168 ...

Just yesterday, my PC lost its connection the internet. When the standard troubleshooting didn't help, I took a closer look and discovered that my PC (actually, the Ethernet NIC in my PC) had obtained the address 169.254.170.79, which is clearly outside the range of addresses available from my router.

With further research I learned that a network device can occasionally assign itself an IP address in the 169.254 ... range when, for whatever reason, it is unable to contact a DHCP server. This is known as a link-local IPv4 address.

The purpose of link-local addresses is to make it possible for a device to continue communicating with other network devices even without an address assigned by DHCP (or assigned manually.) The last two octets (170.79 in my case) are randomly generated to prevent address conflicts.

That's all very interesting, but how can I return to obtaining an IP address from my router?

 

[Ken Atkinson]

As with many home LANs, my router assigns IP addresses (via DHCP) from the range 192.168 ...

Just yesterday, my PC lost its connection the internet. When the standard troubleshooting didn't help, I took a closer look and discovered that my PC (actually, the Ethernet NIC in my PC) had obtained the address 169.254.170.79, which is clearly outside the range of addresses available from my router.

With further research I learned that a network device can occasionally assign itself an IP address in the 169.254 ... range when, for whatever reason, it is unable to contact a DHCP server. This is known as a link-local IPv4 address.

The purpose of link-local addresses is to make it possible for a device to continue communicating with other network devices even without an address assigned by DHCP (or assigned manually.) The last two octets (170.79 in my case) are randomly generated to prevent address conflicts.

That's all very interesting, but how can I return to obtaining an IP address from my router?

This Could just have been a glitch in network connectivity, power cycle router and see if this fixes, if problem keeps occurring there a connectivity/dns resolver issue

Sent from my ONEPLUS A6013 using Tapatalk

 

[ColinTaylor]

That's all very interesting, but how can I return to obtaining an IP address from my router?

Reboot the PC.

 

[coxhaus]

Maybe try a different cable?

 

[RMerlin]

Try resetting your PC's networking stack.

https://kb.wisc.edu/31480

 

[Bulldog]

Thanks for everyone's ideas.

Neither power cycling, nor rebooting, nor ipconfig /release and ipconfig /renew, nor a network reset have any effect, which is not a surprise, because my Ethernet NIC and my router are on different networks.

I also thought about the Ethernet cable, but the same cable works fine on my Chromebook (with an Ethernet-to-USB C adapter.)

If I use a WiFi adapter with my PC, instead of the built-in Ethernet NIC, I have no trouble pulling an IP address via DHCP and thus connecting to the internet, so the problem definitely lies with the NIC.

Fundamentally, the NIC 'lost' the ability to find (the DHCP server in) my router, so it can't obtain an IP address via DHCP and instead assigns a link-local address.

How can I restore the ability of my NIC to find my router?

 

[Deleted member 22229]

How can I restore the ability of my NIC to find my router?

Replace it..

 

[CaptainSTX]

Have you tried giving your PC a static IP using a utility or through Windows itself? If you do assign an IP make sure it is outside the router's pool of addresses but in the same subnet.

 

[degrub]

you can try 1) deleting the drivers and reloading ones from the MB or NIC supplier (not from Microsoft Update).
Otherwise, you may have to disable the device in device manager and install a new NIC suitable for the motherboard PCI bus.

 

[Bulldog]

After further testing, I have to agree with Kal-El and degrub: It's time for a new Ethernet NIC.

Again, assigning a static IP address doesn't help because the NIC can't contact the router.

Here's how I arrived at my conclusion: I booted my PC from a live Linux distro (my Kaspersky 'Rescue Drive') and a Windows PE drive (that I use with my Macrium backup application.) In neither case was my NIC able to pull an IP address from my router. (It was still using the link-local address.) This showed me that the problem was caused by the NIC itself and not by any software in my computer.

Full disclosure: I've been describing it as a NIC but it's actually the Ethernet chip on my motherboard. After I buy an actual Network Interface Card, I'll disable the Ethernet chip and remove all its software, and then install my new NIC. Until then I'll just use the WiFi adapter.

On the one hand, this PC (and thus its Ethernet chip) is 9 years old, so perhaps age is a factor? OTOH, what is there that can go wrong or 'wear out' on a chip?

Thanks for everyone's help.

 

[degrub]

Would it happen to be an AMD based motherboard with a Realtek NIC ?

 

[Bulldog]

Would it happen to be an AMD based motherboard with a Realtek NIC ?

Afraid not. It's a Dell OEM motherboard with a BIOS from AMI (American Megatrends) and an Ethernet chip from Broadcom (57780.)

 

[follower]

As with many home LANs, my router assigns IP addresses (via DHCP) from the range 192.168 ...

Just yesterday, my PC lost its connection the internet. When the standard troubleshooting didn't help, I took a closer look and discovered that my PC (actually, the Ethernet NIC in my PC) had obtained the address 169.254.170.79, which is clearly outside the range of addresses available from my router.

With further research I learned that a network device can occasionally assign itself an IP address in the 169.254 ... range when, for whatever reason, it is unable to contact a DHCP server. This is known as a link-local IPv4 address.

The purpose of link-local addresses is to make it possible for a device to continue communicating with other network devices even without an address assigned by DHCP (or assigned manually.) The last two octets (170.79 in my case) are randomly generated to prevent address conflicts.

That's all very interesting, but how can I return to obtaining an IP address from my router?

Your issue is not that strange. That's a common issue which anyone can have.

Reasons.
1. Your Onboard NIC is dead.
2. Driver issue.
3. Blocked MAC Address by Router or ISP.
4. A compromised router.

You can try.
1. Disable IPv6.
2. Clean install Windows.
3. Disable Onboard NIC and use a new Ethernet card.