Need static IP address across user switching

[MidnightJava]

When I switch users on the Mac, the system grabs another IP address from my DHCP server. The Mac is behind a NATed firewall with an IP address reserved for the Mac based on its MAC address. But since the Mac apparently requests another IP address without releasing the one for the "other" user, it keeps grabbing higher and higher addresses as I switch back and forth between user accounts.

I use port forwarding through the Firewall to route certain IP ports to the Mac, and this behavior makes that impossible. Is there a way to either not request an IP address when switching users, or release the other one first, so it ends up with the same address if it does renew? Or should I disable Fast User Switching?

 

[Pengu]

Um. can you not use a static address?

 

[Go3iverson]

When I switch users on the Mac, the system grabs another IP address from my DHCP server. The Mac is behind a NATed firewall with an IP address reserved for the Mac based on its MAC address. But since the Mac apparently requests another IP address without releasing the one for the "other" user, it keeps grabbing higher and higher addresses as I switch back and forth between user accounts.

I use port forwarding through the Firewall to route certain IP ports to the Mac, and this behavior makes that impossible. Is there a way to either not request an IP address when switching users, or release the other one first, so it ends up with the same address if it does renew? Or should I disable Fast User Switching?

I've never seen OS X request new DHCP leases based on user switching. That's really odd. I mean, the user level shouldn't affect the system level and such anyway.

Any other configs going on? Any non-standard networking?

 

[MidnightJava]

Um. can you not use a static address?

I tried that and it didn't work, but your message reminded me to pursue that option some more. I was hoping to get the mac to work with a static IP address while the other computer on the network (a PC) continued to use the router as a DHCP server. On the Mac in Network System Prefs I set "Configure IPv4" to "using DHCP with manual address" and there was no IP connectivity. I also tried setting it to just "manually," and that didn't work either. In each case, I selected an IP address outside the range of the DHCP server's client addresses, but within the router's subnet.

After reading your response, I decided to turn off DHCP and configure both computers with static IP addresses. That worked, although I had to set the DNS server address manually in each computer's IP configuration. I thought this wouldn't be necessary, since the router is configured with the DNS server's address, but it appears that static IP config also requires manual DNS address config. Perhaps that's all that was missing when I tried to run the Mac with a static IP in a DHCP environment. Maybe I'll try that someday, just to map out the behavior. Anyway, thanks for reminding me to pursue that path.

 

[MidnightJava]

I've never seen OS X request new DHCP leases based on user switching. That's really odd. I mean, the user level shouldn't affect the system level and such anyway.

Any other configs going on? Any non-standard networking?

I'm new to Mac (at least since shortly aftyer the advent of System 8), so I'm nost sure what's non-standard. I recently installed Sharepoints, to enable the PC to get into the Mac file share at any directory, but I'm pretty sure the IP mutation problem was with me before I installed SharePoints.

So obviously I have Windows file sharing enabled. I also share the Mac's printer to the PC, by turning on printer sharing on the Mac and installing a logical printer on the PC that points to the Mac's printer and uses an Applewriter driver. Not much else going on with the LAN. I have the PC and the Mac behind a NetGear router, and I had DHCP service activated, with an IP address reserved for the Mac's MAC address. The router does NAT, and gets a static IP address from my cable ISP.

It would be nice to figure out how to make dynamic IP work, but static IP is not a problem in such a small environment.