• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
  • Welcome to iHelpForum - the place to get help from knowledgeable techs in all areas of Tech, Home and Auto help. Consider checking out our Guides or Registering an account to post on our forums today.

DHCP Issues

Crush

I am admin, ruler of my domain
Administrator
iHF Master Craftsman
#1
Hi guys,

One machine on my network is having problems obtaining an IP address from my DHCP server which is my router.

Static IP connects fine.

For reference:
Diag.jpg

Things I've tried:

-Swapped cables
-Bypassed managed switch
-Shortened DHCP lease time and range
-Rebooted everything
-Changed NICs

Network Troubleshooter built into Windows gives me an error that there's an invalid.

After swapping cables I was able to get a DCHP applied IP address but that didn't survive a reboot.

Static IP:
Pinging GOOGLE.COM [172.217.4.46] with 32 bytes of
Reply from 172.217.4.46: bytes=32 time=6ms TTL=57
Reply from 172.217.4.46: bytes=32 time=6ms TTL=57
Reply from 172.217.4.46: bytes=32 time=6ms TTL=57
Reply from 172.217.4.46: bytes=32 time=6ms TTL=57
DCHP enabled:

Ping request could not find host GOOGLE.COM. Please check the name and try again.
 

Lord Chance

iHelpForum Jester & Door Greeter
iHF Veteran
Advisor
WCG Team Member
#4
Thanks LC

Tried that no dice
What is the exact error you are getting Mate? If it works with a static IP then there is a conflict on your Network. It's not hardware to be sure.

If you have not already, Set a static IP on the affected computer then do a hard reboot. Not a restart but a complete shut down then boot. On reboot reset the affected PC to obtain IP then do another hard reboot. Sounds like windows is not doing the changes in the REGistry. This is why only my wireless devices use my DHCP. :)
 

Lord Chance

iHelpForum Jester & Door Greeter
iHF Veteran
Advisor
WCG Team Member
#5
As a Last ditch effort you can try resetting the TCP/IP stack. This will effectively reset your network adapter to default.

For Widows 8.1
  1. On the Start screen, type CMD. In the search results, right-click Command Prompt, and then select Run as administrator.
  2. At the command prompt, enter the following command, and then press Enter:
  • netsh int ip reset c:\resetlog.txt
Note If you don't want to specify a directory path for the log file, run the following command instead:
  • netsh int ip reset
For Windows 7
  1. To open a command prompt, select Start and then type cmd in the Search programs and files box.
  2. Under Programs, right-click the CMD.exe icon, and then select Run as administrator.
  3. When the User Account Control box appears, select Yes.
At the command prompt, enter the following command, and then press Enter:
  • netsh int ip reset c:\resetlog.txt
Note If you don't want to specify a directory path for the log file, run the following command instead:
  • netsh int ip reset resetlog.txt
  1. Restart the computer.
 

Crush

I am admin, ruler of my domain
Administrator
iHF Master Craftsman
#6
What is the exact error you are getting Mate? If it works with a static IP then there is a conflict on your Network. It's not hardware to be sure.
It completes but does not resolve the issue

If you have not already, Set a static IP on the affected computer then do a hard reboot. Not a restart but a complete shut down then boot. On reboot reset the affected PC to obtain IP then do another hard reboot. Sounds like windows is not doing the changes in the REGistry. This is why only my wireless devices use my DHCP. :)
Tried that too. Oddly other devices both wired and wireless get DHCP leased addresses fine

As a Last ditch effort you can try resetting the TCP/IP stack. This will effectively reset your network adapter to default.
I did this last night too

I've tried just about everything. I'm truly stumped
 

DCiAdmin

Always room to learn a bit more
Administrator
iHF Legend
WCG Team Member
#9
AV on PC? This is the one without, right?

Copy of IPCONFIG /all, please.

No solution here, but worth a read. Similar issue, interesting suggestion at #4 in post 2

Also this, but unlikely
 

Crush

I am admin, ruler of my domain
Administrator
iHF Master Craftsman
#10
Hard to say without looking at your router logs. You do log traffic I assume. When did the problem start? After a windows update? It could be the Firewall, Not resolving the DNS as I assume you use your ISP's DNS. Seems I ASSume too much. Sorry Mate
Machine is configured to get DNS through Google when static, otherwise yeah it's using ISP DNS servers.

AV on PC? This is the one without, right?
Windows Defender


Copy of IPCONFIG /all, please.
Code:
Windows IP Configuration

   Host Name . . . . . . . . . . . . : DESKTOP-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Ethernet:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
   Physical Address. . . . . . . . . : 98-DE-D0-00-60-5A
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Ethernet 2:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Broadcom NetLink (TM) Gigabit Ethernet
   Physical Address. . . . . . . . . : 18-03-73-B3-82-9A
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::4452:8659:60f7:2cf4%10(Preferred)
   Autoconfiguration IPv4 Address. . : 169.254.44.244(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.0.0
   Default Gateway . . . . . . . . . :
   DHCPv6 IAID . . . . . . . . . . . : 102237043
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1E-92-08-1C-18-03-73-B3-82-9A
   DNS Servers . . . . . . . . . . . : 8.8.8.8
                                       8.8.4.4
   NetBIOS over Tcpip. . . . . . . . : Enabled

Wireless LAN adapter Wi-Fi:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : The Broadcom 802.11 Network Adapter provides wireless local area networking.
   Physical Address. . . . . . . . . : C0-F8-DA-80-4A-02
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Local Area Connection* 2:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter
   Physical Address. . . . . . . . . : C2-F8-DA-80-4A-02
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
 

DCiAdmin

Always room to learn a bit more
Administrator
iHF Legend
WCG Team Member
#13
Strange. Got a different switch to swap out?
 

DCiAdmin

Always room to learn a bit more
Administrator
iHF Legend
WCG Team Member
#15
I tried enabling DHCP on my NAS an that has appeared to fail miserably. Guess I'm not going to bed yet :banghead::caution:
Oooo, I wish you wouldn't have done that! You already had your answer when you looked at the Xbox. Ugh....

Good luck!
 

DCiAdmin

Always room to learn a bit more
Administrator
iHF Legend
WCG Team Member
#17
What? Why different results? No IP assigned to the NAS? Reset switch to default or replace.
 

DCiAdmin

Always room to learn a bit more
Administrator
iHF Legend
WCG Team Member
#19
Exactly. Resetting the NAS (luckily with no data loss) and going to replace the switch tomorrow :)
Bet you could have discovered the same thing by doing a release / renew on the Xbox :D
 

Crush

I am admin, ruler of my domain
Administrator
iHF Master Craftsman
#20
Bet you could have discovered the same thing by doing a release / renew on the Xbox :D
Hindsight is 20/20 and now I'm incredibly annoyed.

I thought you know what...I'll sleep when I'm dead. I'm resolving this tonight.

Did a.....switcharoo.....of the switches (thank you, I'm here all week, tip your waitresses) and everything works fine now.

DHCP address pulled down to machine and NAS W.....T......F

EDIT: NAS it back to static address, wheee!
 
Last edited: