Ethernet puzzle

David Empson

Michael H. Phillips <mhp@odtaa.invalid> wrote:

> On Sun, 2 Dec 2007 12:02:46 +0000, Chris Ridd wrote:
>
> > What does
> > System Profiler say *in detail* about the interfaces you're connecting
> > together?
>
> Okay. G5 (Ethernet 1) connected to PB.
>
> PB:
>
> Built-in Ethernet:
>
> Type: Ethernet
> Hardware: Ethernet
> BSD Device Name: en0
> IPv4 Addresses: 169.254.253.161
> IPv4:
> Addresses: 169.254.253.161
> Configuration Method: DHCP
> Interface Name: en0
> Subnet Masks: 255.255.0.0
> IPv6:
> Configuration Method: Automatic
> Proxies:
> FTP Proxy Enabled: No
> FTP Passive Mode: Yes
> Gopher Proxy Enabled: No
> HTTP Proxy Enabled: No
> HTTPS Proxy Enabled: No
> RTSP Proxy Enabled: No
> SOCKS Proxy Enabled: No
> Ethernet:
> MAC Address: 00:03:93:01:c2:be
> Media Options: Full Duplex
> Media Subtype: 100baseTX
>
> G5:
>
> Built-in Ethernet 1:
>
> Type: Ethernet
> Hardware: Ethernet
> BSD Device Name: en0
> IPv4:
> Configuration Method: DHCP
> Proxies:
> Proxy Configuration Method: Manual
> ExcludeSimpleHostnames: 0
> FTP Passive Mode: Yes
> Gopher Proxy Enabled: No
> Auto Discovery Enabled: No
> SOCKS Proxy Enabled: No
> Ethernet:
> MAC Address: 00:14:51:66:32:04
> Media Options:
> Media Subtype: autoselect

This is saying that your G5 has no IP address at all for this interface.
It doesn't think it has a valid Ethernet connection, so it hasn't even
done a self-assigned IP address.

This is almost always due to a hardware fault with an Ethernet port, or
a bad cable, or a failure to auto-negotiate the mode of operation. Try
setting both the PowerBook and G5 to use a fixed Ethernet mode rather
than automatic.

> Now G5 (Ethernet 2) can't connect to PB.
>
> PB:
>
> no change
>
> G5:
>
> Built-in Ethernet 2:
>
> Type: Ethernet
> Hardware: Ethernet
> BSD Device Name: en1
> IPv4:
> Configuration Method: DHCP
> Proxies:
> Proxy Configuration Method: Manual
> ExcludeSimpleHostnames: 0
> FTP Passive Mode: Yes
> Auto Discovery Enabled: No
> Ethernet:
> MAC Address: 00:14:51:66:32:05
> Media Options: Full Duplex, flow-control
> Media Subtype: 100baseTX
>
> Means nothing to me.

Same symptoms. As you are using a different Ethernet port on the G5, it
isn't likely to be due to the G5's Ethernet ports. It will be the cable,
the PowerBook's Ethernet port, or an auto negotiation problem.

--
David Empson
dempson@actrix.gen.nz

Michael H. Phillips

On Sun, 2 Dec 2007 12:38:47 +0000, David Empson wrote:

> In the situation where you are unable to connect by IP address, can you
> confirm that both computers are reporting a self-assigned IP address
> (169.254.xxx.yyy) for the appropriate Ethernet port?
>
> What is the G5's IP address on the Ethernet interface going to the
> modem? Is it also a self-assigned address (169.254.xxx.yyy)? If so, that
> might explain the problem - two self-assigned addresses on different
> interfaces means that an attempt to connect to the PowerBook (also
> self-assigned) could be picking the wrong interface.

It depends on the port configurations. If Ethernet 1 is above Ethernet 2,
then it is
Ethernet 1: 79.97.17.245
Ethernet 2: no address

If Ethernet 2 is above Ethernet 1, then it is
Ethernet 1: 79.97.17.245
Ethernet 2: 169.254.8.52
>
> Some things to try:
>
> 1. See if you can ping the other computer's IP address using Network
> Utility.

In the non-working configuration, no.
>
> 2. Can you connect to the PowerBook reliably if you unplug the Ethernet
> cable going to the modem?

Makes no difference, so no.
>
> 3. Try adjusting the Ethernet port settings on one or both computers to
> force them both to the same mode. They might be mis-negotiating the
> physical connection. A PowerBook G4/400 doesn't support Gigiabit
> Ethernet, so it should be auto-negotiating 100Base-TX Full Duplex. I
> don't recall offhand whether that model supports Auto-MDX. Try manually
> assigning both computers to 100Base-TX and forcing Full Duplex.

Makes no difference.
>
> 4. Try a different Ethernet cable.

First thing I tried.
>
> 5. Try manually assigning static IP addresses to both the G5 (for the
> interface going to the PowerBook) and the PowerBook G4. Use easy to
> remember private IP addresses like 10.0.0.1 and 10.0.0.2 (assuming you
> aren't using that range elsewhere).

Makes no difference.

>>
>> Yes! I dragged Ethernet 1 below Ethernet 2 and I can't connect. Restored
>> Ethernet 1 to top and I can connect.
>
> Not sure what this proves. As I said before, it doesn't make sense.
>
> Were you able to connect if you swapped the cables over after reversing
> the order of the Ethernet ports, so the PowerBook was still connected to
> the first interface in the list?

Yes. It works as long as the PowerBook is connected to the first interface,
be it Ethernet 1 or ethernet 2.

--
Michael

mhphillips at gmail dot com

Michael H. Phillips

On Sun, 2 Dec 2007 12:43:20 +0000, David Empson wrote:

> As you are using a different Ethernet port on the G5, it
> isn't likely to be due to the G5's Ethernet ports. It will be the cable,
> the PowerBook's Ethernet port, or an auto negotiation problem.

It's a second-hand PowerBook so it's quite possible that there's a problem
there, especially as I know the Firewire port to be broken.

--
Michael

mhphillips at gmail dot com

David Empson

Michael H. Phillips <mhp@odtaa.invalid> wrote:

> On Sun, 2 Dec 2007 12:38:47 +0000, David Empson wrote:
>
> > In the situation where you are unable to connect by IP address, can you
> > confirm that both computers are reporting a self-assigned IP address
> > (169.254.xxx.yyy) for the appropriate Ethernet port?
> >
> > What is the G5's IP address on the Ethernet interface going to the
> > modem? Is it also a self-assigned address (169.254.xxx.yyy)? If so, that
> > might explain the problem - two self-assigned addresses on different
> > interfaces means that an attempt to connect to the PowerBook (also
> > self-assigned) could be picking the wrong interface.
>
> It depends on the port configurations. If Ethernet 1 is above Ethernet 2,
> then it is
> Ethernet 1: 79.97.17.245
> Ethernet 2: no address
>
> If Ethernet 2 is above Ethernet 1, then it is
> Ethernet 1: 79.97.17.245
> Ethernet 2: 169.254.8.52

That suggests the G5 isn't bothering to initialize Ethernet 2 unless
Ethernet 2 is the default interface (i.e. the first one in the list).

I assume that in this case, Ethernet 1 is going to your modem.

> > 2. Can you connect to the PowerBook reliably if you unplug the Ethernet
> > cable going to the modem?
>
> Makes no difference, so no.

Ok. This implies it only matters whether the PowerBook is connected to
the primary interface, and it doesn't matter what the other interface is
doing.

> >> Yes! I dragged Ethernet 1 below Ethernet 2 and I can't connect. Restored
> >> Ethernet 1 to top and I can connect.
> >
> > Not sure what this proves. As I said before, it doesn't make sense.
> >
> > Were you able to connect if you swapped the cables over after reversing
> > the order of the Ethernet ports, so the PowerBook was still connected to
> > the first interface in the list?
>
> Yes. It works as long as the PowerBook is connected to the first interface,
> be it Ethernet 1 or ethernet 2.

I think this is what is happening:

The modem and G5 and behaving normally, but the PowerBook has a problem.

The G5 always attempts to initialize its primary network interface
(according to the order in the list). This is triggering a valid
connection with the PowerBook or the modem. The PowerBook is working
well enough to maintain an Ethernet connection as long as the G5
initiates it.

The G5 only attempts to initialize its secondary network interface if it
senses another device is connected. The modem is providing the correct
signals, so the G5 is able to detect it and will initialize the
secondary interface if the modem is connected to it.

The PowerBook is NOT providing the correct signals, so the G5 thinks
nothing is plugged in and never bothers initializing the secondary
interface if the PowerBook is connected to it.

Solution: connect the PowerBook to the G5's primary interface.

You should eventually replace the PowerBook, or perhaps get a PC Card
Ethernet interface for the PowerBook and stop using its built-in
Ethernet.

--
David Empson
dempson@actrix.gen.nz

Chris Ridd

On 2007-12-03 13:14:27 +0000, dempson@actrix.gen.nz (David Empson) said:

> Solution: connect the PowerBook to the G5's primary interface.

Another one: use IP over a firewire cable between the two.

Cheers,

Chris

Michael H. Phillips

On Mon, 3 Dec 2007 13:14:27 +0000, David Empson wrote:

> The PowerBook is NOT providing the correct signals, so the G5 thinks
> nothing is plugged in and never bothers initializing the secondary
> interface if the PowerBook is connected to it.
>
> Solution: connect the PowerBook to the G5's primary interface.
>
> You should eventually replace the PowerBook, or perhaps get a PC Card
> Ethernet interface for the PowerBook and stop using its built-in
> Ethernet.

That sounds plausible. Even though I can get it to work by re-arranging the
order of interfaces, I might just get a PC card to confirm your theory and
satisfy my curiosity.

Thanks for all the wisdom, David.

--
Michael

mhphillips at gmail dot com

Michael H. Phillips

On Mon, 3 Dec 2007 13:20:10 +0000, Chris Ridd wrote:

> On 2007-12-03 13:14:27 +0000, dempson@actrix.gen.nz (David Empson) said:
>
>> Solution: connect the PowerBook to the G5's primary interface.
>
> Another one: use IP over a firewire cable between the two.

I saw that mentioned in the G5's manual but it was a little sketchy on how to
set it up. I must investigate further. Of course the Firewire port on the
PowerBook is knackered, but I do have a PC card...

--
Michael

mhphillips at gmail dot com

Chris Ridd

On 2007-12-03 16:58:21 +0000, Michael H. Phillips <mhp@odtaa.invalid> said:

> On Mon, 3 Dec 2007 13:20:10 +0000, Chris Ridd wrote:
>
>> On 2007-12-03 13:14:27 +0000, dempson@actrix.gen.nz (David Empson) said:
>>
>>> Solution: connect the PowerBook to the G5's primary interface.
>>
>> Another one: use IP over a firewire cable between the two.
>
> I saw that mentioned in the G5's manual but it was a little sketchy on how to
> set it up. I must investigate further. Of course the Firewire port on the
> PowerBook is knackered, but I do have a PC card...

Weren't there two FW ports on the TiBook?

Cheers,

Chris

Michael H. Phillips

On Mon, 3 Dec 2007 17:15:55 +0000, Chris Ridd wrote:

> On 2007-12-03 16:58:21 +0000, Michael H. Phillips <mhp@odtaa.invalid> said:
>
>> On Mon, 3 Dec 2007 13:20:10 +0000, Chris Ridd wrote:
>>
>>> On 2007-12-03 13:14:27 +0000, dempson@actrix.gen.nz (David Empson) said:
>>>
>>>> Solution: connect the PowerBook to the G5's primary interface.
>>>
>>> Another one: use IP over a firewire cable between the two.
>>
>> I saw that mentioned in the G5's manual but it was a little sketchy on how
>> to
>> set it up. I must investigate further. Of course the Firewire port on the
>> PowerBook is knackered, but I do have a PC card...
>
> Weren't there two FW ports on the TiBook?
>

Only one on this 400MHz model. But, using the PC card, I have successfully
connected with IP over Firewire. But guess what! It will only work if I drag
Built-in Firewire to the top of the list in Network Port Configurations on
the G5. This really is great fun.

I'm going to see what happens if I try it when the PowerBook is booted into
OS9.

--
Michael

mhphillips at gmail dot com

Michael H. Phillips

On Mon, 3 Dec 2007 17:22:53 +0000, I wrote:

> I'm going to see what happens if I try it when the PowerBook is booted into
> OS9.

Doesn't work. "Incompatible version of AFP". And it caused OS9 to crash. It's
a long time since I've seen the bomb.

--
Michael

mhphillips at gmail dot com