I have 4 computers connected to a peer to peer network. I have one connected in a back office directly to the dsl router. The other 3 computers are in the front and instead of running 4 lines from the front to the back I ran one line from router to the front where I installed a switch and connected the 3 computers into the switch. Well one of them works fine and got an ip adress of xxx.xxx.xxx.9, and then the other one gets xxx.xxx.xxx.7 and then the second obtained the same Ip address .7. So then on one of them I made it so that one of the machines would use xxx.xxx.xxx.8. Well now today the other machine is using .8 why is this happening I changed the other one to use .7 but I want to know why this is happening.
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2 computers obtaining same IP address
- Thread starter tonycard
- Start date
Several thoughts:
. Never assign a static IP within the scope of your DHCP server -- in this case the router. The web page setup of your router should show the starting and ending IPs used by the DHCP server. Do not confine the DHCP server, as you have lease times to consider. Even with four computers, leave it at the default setting which is likely 40 IPs within the DHCP scope;
. Lease times are determined and issued by the DHCP server and preserved by the client and respected by the DHCP server. You likely can adjust the lease interval in the router; a better choice is just to let the workstations and DHCP server negotiate this.
. Win2k and XP are relatively lazy about DHCP renewal, and you need to let the DHCP server handle this issue by using the advice above. See:
. A click on a DHCP enabled workstation client on the notification tray icon for the network, Repair, will fix any temporary issues.
. Never assign a static IP within the scope of your DHCP server -- in this case the router. The web page setup of your router should show the starting and ending IPs used by the DHCP server. Do not confine the DHCP server, as you have lease times to consider. Even with four computers, leave it at the default setting which is likely 40 IPs within the DHCP scope;
. Lease times are determined and issued by the DHCP server and preserved by the client and respected by the DHCP server. You likely can adjust the lease interval in the router; a better choice is just to let the workstations and DHCP server negotiate this.
. Win2k and XP are relatively lazy about DHCP renewal, and you need to let the DHCP server handle this issue by using the advice above. See:
. A click on a DHCP enabled workstation client on the notification tray icon for the network, Repair, will fix any temporary issues.
- Thread starter
- #3
. I suggested a repair, not an ipconfig/relase and renew
. I explained that Win2k and XP are lazy about DHCP renewals if the subnet and mask are essentially identical to what they have now, and provided an MS KB discussing this behavior;
. Fundamentall this is an issue with lease times, and likely the DHCP server on your router. I note that DHCP renewal issues have plagued most SOHO router manufacturers, and likely in the changelog of any firmware release in the last two years has been "Fixed DHCP renewal issues".
Go to the web site of your router manufacturer, and if possible do a firmware upgrade of the router.
But it was decidedly not a good idea to make static a DHCP scoped IP on one of your workstations. This issue will resolve itself by placing all workstations back to DHCP and following the suggestions here and above.
Best wishes,
Bill Castner
Update the firmware of your router.
. I explained that Win2k and XP are lazy about DHCP renewals if the subnet and mask are essentially identical to what they have now, and provided an MS KB discussing this behavior;
. Fundamentall this is an issue with lease times, and likely the DHCP server on your router. I note that DHCP renewal issues have plagued most SOHO router manufacturers, and likely in the changelog of any firmware release in the last two years has been "Fixed DHCP renewal issues".
Go to the web site of your router manufacturer, and if possible do a firmware upgrade of the router.
But it was decidedly not a good idea to make static a DHCP scoped IP on one of your workstations. This issue will resolve itself by placing all workstations back to DHCP and following the suggestions here and above.
Best wishes,
Bill Castner
Update the firmware of your router.
- Thread starter
- #5
Well if the router is causing that much hassles, would be easier to set static ip addresses yourself. Make note of what dns servers you get from dhcp, then enter that stuff into the tcp/ip setup, with the default gateway the address of the router.
dakota81,
A perfectly reasonable choice with such a small LAN. But DHCP should work, it is just occasionally fussy. I am quite serious about the number of SOHO class routers that have gotten this wrong in firware in the last year. The changelogs from many are consistent in mis-handling DHCP and trying to fix the issue, particularly with renewals of DHCP leases. And XP SP2 inttroduced a whole nother set of issues, as it is fairly demanding that the DHCP process follow the standards exactly.
A perfectly reasonable choice with such a small LAN. But DHCP should work, it is just occasionally fussy. I am quite serious about the number of SOHO class routers that have gotten this wrong in firware in the last year. The changelogs from many are consistent in mis-handling DHCP and trying to fix the issue, particularly with renewals of DHCP leases. And XP SP2 inttroduced a whole nother set of issues, as it is fairly demanding that the DHCP process follow the standards exactly.
bcastner - I know it's pretty much always better to use dhcp than static ip addresses, and the hardware should be troubleshooted. I suppose by now I typically go by the philosiphy of making it work now & troubleshooting later when time permits.
Bill,
i've found 'proof' that you are an expert in many domains...
all the best,
David
![[wiggle]](/data/assets/smilies/wiggle.gif "[wiggle] [wiggle]")
Aftertaf (david)
MCSA 2003
i've found 'proof' that you are an expert in many domains...
all the best,
David
Aftertaf (david)
MCSA 2003
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