Computer's local hostname already in use--wireless networking not functioning

I'm running 10.4.3 on a PowerBook G4.

I had been using a NetGear router, which fed one wired connection into a PC, and one wired connection into an Airport Express, with the PowerBook getting wireless access through the AE. But then I the wifi and the router stopped working, and around the same time, I started getting the message:

"The computer's local hostname 'firstname-lastnames-Computer.local" is already in us on this network. The name has been changed to 'firstname-lastnames-Computer-2.local' automatically."

I gradually removed the Airport Express and the router, so that now, it is just a PowerBook plugged into an RCA cable modem provided by TimeWarner.

I can get a network connection that way, but if I try to add the Airport Express connection back in, the AE just blinks amber, and will not give me a network connection. After trying to add the AE back into the chain, not even the plain wired connection to the cable modem will work for a while. But after a while, I will get the "hostname already in use--changed automatically" message, and the plain wired network connection will start working again. I am up to firstname-lastnames-Computer-5.local now.

Any ideas on what I can do to insert the router and/or the Airport Express (it's mainly wireless that I want) back in the chain successfully?

This sounds like a routing or dhcp problem, or both.

I've not used the AE personally, but as far as I'm aware it's a DHCP capable router. The chances are your Netgear can also do this, and having two devices on the network trying to do the same job isn't a good idea.

If the AE has an option for DCHP (the thing that dishes out ip addresses etc), then make sure it's turned off. Your Netgear router should have it turned on by default. Really that's all you should need to do. I have never had that message, although I have had similar when my router gave my wired PC an IP address, then my access point gave my laptop the same one, and networks don't like that

Is there any chance your wired machine and laptop have the same computer name?

Thanks for your help, chuckalicious.

Is there any chance your wired machine and laptop have the same computer name?[/QUOTE]

I do have it set up so that the router is using DHCP to give out IP addresses, and the Airport Express stations (there are actually two of them, with one creating the wireless network and the other extending it) not distributing IP addresses.

More recently, I got a message saying "IP Configuration 192.168.0.4 in use by 00:04:40:06:1f:82, DHCP Server 192.168.0.1". The dialog box with that message will come up periodically as long as the Airport Expresses are plugged into power and one is plugged into the router. Also, I have agaiin received the message saying the local hostname was in use, and the name was being changed.

Here is the thing. I cannot figure out what has that ...0.4 IP address and ...1f:82 MAC address on the network. That is not the "Internet port MAC address" or the "LAN port MAC address" for the Netgear router. It is also not the MAC address for either of the Airport Expresses or the PowerBook's internal Ethernet card.

I accessed the router through my browser, and clicked on "Attached Devices." Here is the list of Attached Devices:

# IP Address Device Name MAC Address
1 192.168.0.2 00:11:24:08:4c:88
2 192.168.0.3 00:14:51:6d:15:7c
3 192.168.0.5 00:0a:95:da:4f:24

The first two addresses are the two AE's, and the third is the internal Ethernet card of the PowerBook.

I ran "Netstat" under Network Utility to get "Routing Table Information," and here is what I get (with some identifying info removed):

Internet:
Destination Gateway Flags Refs Use Netif Expire
default 192.168.0.1 UGSc 23 10 en0
127 localhost UCS 0 0 lo0
localhost localhost UH 11 2400 lo0
169.254 link#4 UCS 0 0 en0
192.168.0 link#4 UCS 3 0 en0
192.168.0.4 link#4 UHLW 1 1 en0
192.168.0.5 localhost UHS 0 14 lo0

Internet6:
Destination Gateway Flags Netif Expire
localhost link#1 UHL lo0
localhost Uc lo0
localhost link#1 UHL lo0
link#4 UC en0
justin-and-******* 0:95:da:4f:24 UHL lo0
****************bedro 0:14:51:6d:15:7c UHLW en0
link#5 UC en1
justin-and-******* 0:95:f3:3e:df UHL lo0
****************bedro 0:14:51:6d:15:7c UHLW en1
ff01:: localhost U lo0
ff02::%lo0 localhost UC lo0
ff02::%en0 link#4 UC en0
ff02::%en1 link#5 UC en1

Any ideas?

Problem apparently solved

I think I have figured this figured out. There was also a Slimdevices Squeezebox on my wireless network, about which I had completely forgotten. I unplugged its power cord, and now the wireless network seems to be doing fine.

I had configured the squeezebox when I only had one Airport Express. My guess is that when I added the second Airport Express, and plugged the ReplayTV into the second AE, that configuration conflicted with the Squeezebox.

When I have some time, perhaps I will try to reconfigure the Squeezebox to work with everything, but for now, I am content with the way things are.

For anyone who read this subject line because they were having a similar problem, the moral of the story in my case was to search for wireless devices you had not thought about, and either disconnect them or make sure they are properly configured.

Ah It may be that the Squeezebox has been trying to use the same IP over and over, possibly even static, but the DHCP server won't know that, and will dish out that IP anyway.

Glad you got it sorted

chuckalicious said:

Ah It may be that the Squeezebox has been trying to use the same IP over and over, possibly even static, but the DHCP server won't know that, and will dish out that IP anyway.

Glad you got it sorted

Click to expand...

Right. It was either that, or the Squeezebox forums suggest that there was a bug in an earlier version of the Squeezebox software that would falsely represent the Squeezebox's MAC address to the world. Which seems like it might confuse things and cause the problems I was seeing. Anyway, with an installation of fresh Squeezebox software, and a re-initialization of the settings, telling the Squeezebox to accept the IP address it is given, the whole thing is working well, including the Squeezebox.

Thanks again for your help.