can't connect to 169 network

[jvf]

Hello,
I’m new to the forum. Hope this post is in the right place. I’ve searched MAC and the web everywhere but can’t find an answer. My friend has a PC network with the broadband router using a 169.xxx.xxx addressing scheme for DHCP addresses. He wants to connect his wife’s Mac OS 10.5 laptop but when it gets the 169 address it freaks out and says no network available (or some such message-I forget). I tried assigning it a 169 address manually but it still didn’t work. She’s mad because she can’t connect to the Internet and I’m mad because I can’t figure this out. I don’t want to bring the whole network down changing the addressing scheme because I have VPN set up. HELP!

 

[6string]

I'm not sure you will be able to achieve this with the 169 address.
This is beyond my realm of networking knowledge, but this may explain things.
Mac OS: How to release and renew a DHCP lease

 

[jvf]

Thanks 6string,
I’m a leftie and have to restring all my guitars. The Apple article, as all others I’ve seen, starts with the assumption that a 169 address is invalid so does not offer any advice on how to connect to a “real” 169 network. I’m starting to fear that this is another example of Steve’s alternate reality-it doesn’t exist in Mac land, therefore it can’t be real.

 

[gsahli]

Has nothing to do with "Mac Land."
169.X.X.X is it really an invalid IP ?? - The PC Guide Discussion Forums
https://learningnetwork.cisco.com/message/62223
Invalid IP address [Archive] - The macosxhints Forums

 

[jvf]

Hi ghasli,
Maybe it’s a matter asking my question properly? These articles recognize that a 169 address can be valid but that they are always on a private network with no DHCP server. Perhaps they mean peer to peer network (which is what they are describing)? At any rate, this network DOES have a DHCP router assigning addresses in the 169 range which the PCs (even though they also have the ability to self assign 169 addresses) happily accept and off to the Internet they go as well as print to network printers, etc.

It seems that there is an instruction set in the Mac that, once it sees a 169 address, makes the assumption that it is self assigned. Therefore, it doesn’t accept (or recognize the validity of) a 169 gateway address and refuses to join the valid 169 network.

I am asking if there is a way around this conundrum and enabling the Mac to join a valid 169 network without reprogramming the router, all static local IPs and resetting all VPN connections. Perhaps there is an additional setting in the Mac networking interface somewhere?

 

[jvf]

I'm remembering something. A couple of years ago, I brought MY wife's Mac laptop to this network when testing the Mac version of RDP. Her laptop joined the network without complaint but it was 10.4 (Tiger?). I'll try her's again. Maybe the other Mac is unhappy or it is a 10.5 problem. Actually, I just put 10.6 (Snow leopard) on my wife's. But, I'm going to try it this weekend anyway.

 

[6string]

see the bottom of this.... It may help.
AirPort troubleshooting guide
Force reconfiguration of IP information

 

[jvf]

Thanks,
I'll check all this out when I'm at the network. I appreciate everyone's input. It helps me to think things through. I'll report back after I've tried the other Mac. If it works, this post might be modified to inquire what particular malady the 10.5 Mac might have.

 

[gsahli]

always on a private network with no DHCP server.

Private network means the computer "isolated, by itself." Your/her Mac is responding correctly to a 169.xxx IP address.

 

[jvf]

Hi gsahli,

My friend claims that the Mac is OK at home but I’m starting to wonder whether that is really true. In addition to testing my wife’s Mac at their place, I’m going to bring the “broken” one to my place and see if it connects to my 192 network.

It could be the bizarre coincidence that the Mac can’t really connect to any network and so assigns itself a 169 but, 169 IS the network and confusion reigns. OUCH!

 

[MikeM]

Generally, 192.x.x.x and 10.x.x.x are reserved for private networks and 169.x.x.x is a range set aside for failed DHCP attempts. I think that having a 169 DHCP range is confusing the system because it is expecting that to be an invalid range. changing the scope to 192. or 10. might correct the issue. Otherwise, there is a problem with the network stack of her machine.

-MikeM

 

[jvf]

Hello all,
Good thoughts MikeM but read on. With a bit of luck, it was a successful test with my wife’s Mac. It is not a NETWORK connection problem; it is an INTERNET connection problem. Or rather, a browser software problem-specifically Mac’s Safari browser. So, I may have to move this post to another area. What would you suggest? My (admittedly limited) expertise is in connecting machines to a network, not getting them to the Internet. I had no idea that underneath the surface, a browser has all manner of connection settings.

Briefly put, I connected to the Internet straight away using my wife’s Mac and Firefox. Mind you that, in the network preferences pane, the warning still appears that the machine has a self-assigned address and will not be able to connect to the Internet. Over I went to the unhappy Mac which was using Safari and it failed to connect. Back to my wife’s machine to find and launch Safari and got the same “Safari can’t connect to the Internet” message. The final insult is hurled by Safari as it presents a diagnose button to test the connection. Pressing the button results in the cheerful message that “your Internet connection seems to be working properly”. Ya think????

Anyway, there are preferences in Safari to fiddle with the proxy settings. One seems to exclude the 169 address range but deleting the 169 reference didn’t help. Perhaps someone more knowledgeable than me might have an answer other than to just install Firefox (my first choice if approved by the machine’s owner).

Thanks to everyone!

 

[MikeM]

On the network section of System Preferences under Advanced -> TCP/IP what do you see in the following fields?

IPv4 address: XXX.XXX.XXX.XXX
Subnet Mask: XXX.XXX.XXX.XXX
Router: XXX.XXX.XXX.XXX (This is also called a gateway)

Then the DNS Tab:

DNS Servers:
XXX.XXX.XXX.XXX
XXX.XXX.XXX.XXX

Lastly, there should be no boxes checked at all in Proxies unless you are using a Proxy server (Which you won't be unless you specifically set one up)

If the Router field and/or the DNS Servers are blank, that would be a problem. If they have info, then Ping them to see if her machine can hit them.

-MikeM

Edit:
It would seem that Firefox has it's own Proxy Server section independant of the OS in it's preferences (The one you referred to in Safari is actualy the Overall System Preferences). Go to Firefox, Open Preferences, click on advanced, then Network and Settings. If anything is in there, make the Proxy settings for the system identical.

 

[jvf]

Hi MikeM,

Good call. As you can probably tell, I’m not a Maxpert yet. I checked on my wife’s Mac. Indeed, Safari brings up the proxies tab found in network preferences and is not a part of Safari itself.

Unfortunately, I’m not at the 169 network now. But, from memory, the Mac had a valid assigned 169 address of 169.254.93.9 (.3 for my wife’s Mac) with the usual subnet mask of 255.255.255.0 and the router entry correctly showed our DHCP router’s address of 169.254.93.69. DNS server tab was blank on my wife’s Mac. I clicked “advanced” and added it to the DNS field on the “upset” Mac but it didn’t help so I deleted it (it’s now gray, it didn’t really disappear.) I seem to recall that, after a short period of time on either machine, the DNS entry field would appear under the router field in the first network preference window and be filled in with the router’s address.

From this I conclude that the DHCP router has done its job and, in spite of the incorrect warning about having a “self assigned address”, the Mac’s TCP/IP stack has been correctly figured and it’s good to go.

Based on the realization that the proxy info displayed by Safari is really a system setting I am even more confused because the settings look identical on both machines with no proxies checked. I edited the “bypass proxy” window to erase the 169.254/16 entry on the “upset” Mac but that didn’t do anything. At that point I was guessing because I don’t understand the implications of “bypassing” the proxy except to think that bypassing any 169 proxy might actually be a good thing.

Firefox is configured to “use system proxy settings” and can connect but Safari cannot connect on either machine. So, why not? What proxy configuration does Safari need that Firefox doesn’t need? That is the question. However, to complete the test, I need to install Firefox on the recalcitrant Mac to see if it can connect. I am awaiting approval to do so and should know sometime during the weekend.

jvf

 

[jvf]

Hello all,

Slight delay in retesting until next week. Also, it turns out that what they really want to do is use iChat to talk to grandkids. So, Safari or Firefox wouldn’t even need to be open. I guess what I need to do is try and ping an external DNS server to see if this laptop is getting out even if Safari won’t.

 

[jvf]

Hello everyone,

There’s been a delay getting to the laptop. Since grandma said it worked before but suddenly stopped I’m thinking that maybe iChat might not be configured properly. So, to review, I’m going to see if I’m actually able to connect to the Internet before trying iChat.

 

[jvf]

Hello,
Tests results are this:
1) I can ping the external DNS server.
2) I can renew the Mac’s 169 DHCP lease
3) Safari won’t connect to the Internet but the diagnostic check says “your Internet connection appears to be working properly”
4) Installed Firefox but it won’t connect either. I tried system proxy, auto proxy and no proxy.
5) iChat will not connect

Grandma swears that the laptop works fine at home. She and her daughter swear that it worked fine at the office but one day they couldn’t connect with iChat. Other PC computers on the network have no trouble getting out.

Does anyone know what is wrong if the external Gateway can be pinged and Safari’s test thinks the connection is OK but won’t connect to a web page? The “bypass proxy settings” list looked normal but, how can I do a reset of system proxy settings in case a file somewhere has been altered or corrupted?

Thanks,
jvf

 

[gsahli]

Although I guess it's a fun experiment to try, I'm wondering why you don't believe us when we tell you that an interface (ethernet or WiFi) with 169 IP addresses is treated as a non-working interface?
I still say that everything you have experienced is just as it is predicted to be with a 169 IP address.

 

[Deckyon]

Best practices here is to NOT EVER have 169.x.x.x as a DHCP address range set up in a router. Never. IF a computer happened to get access via 169.x.x.x then it is a fluke and I would love to get my hands on it. If he purposefully set up a 169.x.x.x address, box his computer up and ship it back.

Get in the router and set up either a 192.168.x.x DHCP scope or 10.0.x.x DHCP scope. Do that, and I can pretty much guarantee that (barring Security key issues) you will get a connection. If they wont let you change it, walk away or charge then a helluva lot of money by the hour to spin your wheels.

For $250 / hour + travel I will come work on getting it set up.

 

[jvf]

Hello gsahli,
We certainly agree on one thing. Using a169 address can definitely cause unpredictable results. I have devised a test which should settle the matter. Time does not permit it at the moment but I will post a more detailed reply later with some final comments.