# imac g5 ip address problem



## peterghasp (Jan 18, 2009)

hi

My son has just bought a secondhand imac g5. he has had problems getting it on the internet at Uni. So I am now trying to set it up on my home network.
this is a Virgin media broadband connection, with a netopia router wgr614v4 the router and the connection have been working fine for a number of years.

the mac is being connected via cable (not wifi) to the router. in network settings I select Built-in Ethernet. when just setting the configure IPv4 to DHCP it gets assigned an obscure IP address. This varies but is like 169.254.106.21. I can set it manually to 192.168.0.11. with the router address 192.168.0.1. If i do this the diagnostics say that Built in Ethernet is ok and network setting are ok but not the ISP (this goes on and off). I cannot ping or connect to the router. I did get a connection to the internet once after setting the virgin media DNS values in the DNS. 

Does this indicate there is a problem with the mac and any suggestions as to why it gets assigned a strange IP address and by what.

it has mac Os 10.4.11 and has internet connect.
any thought and advice


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## MisterMe (Jan 18, 2009)

Launch *System Preferences*.
Locate the _Internet & Network_ group.
Launch the *Network* preferences pane.
Select the _Show: *Built-in Ethernet*_ pop-up menu.
Click the *TCP/IP* tab.
Select the _Configure IPv4: *Using DHCP*_ pop-up menu.


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## gsahli (Jan 18, 2009)

When set to DHCP and it gets an IP address of 169.x.x.x, that means something wrong in either the router or the Mac DHCP client software. The real fix for that may be extensive like reinstalling OS X via Archive & Install.
On the other hand, I quite often use a manual setup, and it works just fine.
So, in Built-in Ethernet > TCP/IP tab, set configure manually, enter an IP address that no other computer is likely to receive by DHCP, subnet mask 255.255.255.0, gateway 192.168.0.1, DNS servers 192.168.0.1 (same as router), and 208.67.220.220 (openDNS). Go to Configure IPv6 and turn Off.

Good luck.

PS - I "think" I've heard that with some routers, having IPv6 On will cause those symptoms.


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## peterghasp (Jan 18, 2009)

thanks for the posts

if i set it to use DHCP it does not find an address 

if I set the IP manually it gets further but still does not get to the isp

so it seems that there is a problem getting an IP address from the router.

I noticed that the only time I have connected tot he Internet was when I entered the Virgin media dns server address 194.168.8.100 but I should have to do this.

I notice that a lot of other people seem to have similar problems but none with answers that fit this. Is it possible that some thing has become corrupted on the mac?

I have turned IPv6 on and off 

is it possible that Internet Connect


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## Satcomer (Jan 18, 2009)

First of all the 169.xx.xxx.xxx address is a self assigned address when it can't get an IP from source.  This is caused by either a bad cable or router not dishing out an IP. The million dollar question is the router doing DHCP as well as WEP on it's switch ports? You have to look in the router to see if it is.


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## gsahli (Jan 18, 2009)

Ya, now that you've tried that stuff, do what Satcomer is suggesting and try a different cable and port on the router.


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## peterghasp (Jan 19, 2009)

The router is currently set to use DHCP and WEP for the wifi. I thought that WEP was only used by the Wifi not the fixed links. Have tried different cables.

I have also found that if you use the setup assist to connect to a network (not cable or adsl) it will sometimes find and set up a DHCP connection. but looses it after about a minute.


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## peterghasp (Jan 19, 2009)

Also on the router the imac can be seen, as the imac boots up, as an attached device with a mac address and an IP address. but the mac disapears on the router and the mac can not find the ip address and makes  its own up?


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## peterghasp (Jan 30, 2009)

found a solution to the problem:

return the computer and get the supplier to replace the faulty part.

this was done surprising quickly, three days, and all paid for by the supplier (WeSellMac.com). 

the problem with macs is nobody believes they break.


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