TL;DR - File sharing performance is extremely poor on a Mac Pro running 10.8.2 with file sharing enabled. Using it as a Time Machine server also no longer works in this setup.

I have been experimenting with using a Mac Pro (early 2008) as an Internet Sharing machine for other devices in my flat. The Mac Pro is setup as follows:

Cable/Fibre Modem -> PPPoE Interface -> Ethernet 1 -> Wi-Fi (Internet Sharing) -> Client Devices.

Everything seems to be working relatively well. Client machines can connect to the shared network and access the internet as expected (the internet appears to be quick). Most bonjour services appear on the client machines - for example the Mac Pro has file sharing enabled and this appears on my Macbook as an avaiable network location. Plex media server is also running on the Mac Pro and the Xbox and my phone pick this up too.

I also run a local MAMP server on the Mac Pro and have setup Named/BIND to allow .dev URLS to resolve to the Mac Pro. This works too with the client machines being able to browse to .dev URLs and the websites work as expected.

Rather pleased I sat down to enjoy a beer... and then came the time to use file sharing. Connecting to the Mac Pro and browsing directories is extremely slow - almost unusable. Copying files takes an age. I have been experimenting and pressing buttons and searching all evening and so far I cannot find a good reason as to what would be causing the poor performance.

I have also been using a file share on the Mac Pro as a time machine backup drive. With a router in the mix my Macbook will backup to a shared drive without a problem but directly connecting via Internet Sharing gives some very odd results. It says it cannot find the disk and I can no longer use any of the Mac Pro drives as time machine disks. Time Machine throws "The backup disk is not available." at me each time I try.

The final problem I have noticed in this setup is that Airfoil on the Macbook cannot find Airfoil Speakers on the Mac Pro.

My hunch is that all these things are related and possibly caused by various subnets created by running the Mac Pro in this way. I am also thinking it may be related to IPv6 as Little Snitch shows the Macbook with an IPv6 address running on the AppleFileServer process. On the services that work it shows an IPv4 address 192.168.2.X

Digging Deeper

Ethernet 1 is assigning itself an IP along the lines of: 169.254.x.x Subnet Mask

Wi-Fi is also assigning itself a similar IP address: 169.254.x.x with the same Subnet Mask

The PPPoE connection is connecting well and using my specified DNS servers ( - for local DNS and This seems to get its IP from the fibre modem and I don't really understand what happens beyond that.

Client machines are connecting to a router (the Mac Pro) - and have DHCP assigned addresses of 192.168.2.x - They are picking up the DNS settings from the PPPoE connection.

Internet Sharing is enabled between the PPPoE conenction and Wi-Fi.

I tried to share the connected between Ethernet 1 and the Wi-Fi but this stopped everything from working.

I have also had a look at the IP tables (netstat -nr) but it makes very little sense to me. Output below:

Destination        Gateway            Flags        Refs      Use   Netif    Expire
default            195.XXX.XXX.XXX    UGSc           38    95000    ppp0
default            link#4             UCSI            0        0     en0
default            link#6             UCSI            2        0     en2
default            link#9             UCSI            0        0 bridge0
127                UCS             0        0     lo0          UH              6     1617     lo0
169.254            link#4             UCS             1        0     en0          UHS             0        1     lo0          UHS             1        0     lo0    ff:ff:ff:ff:ff:ff  UHLWb           0       10     en0
192.168.2          link#9             UC              6        0 bridge0        ac.de.48.67.b2.89  UHLWIi         10      729     lo0       20.c9.d0.79.cb.75  UHLWIi          4    54472 bridge0   1082   UHLWIi          0      211 bridge0    620       d8:0:4d:ed:b3:de   UHLWIi          0        0     en2   1193       d8.0.4d.ed.b3.de   UHLWIi          0       71 bridge0   1193       link#9             UHRLWIi         0      423 bridge0      8      ff.ff.ff.ff.ff.ff  UHLWbI          0        5 bridge0    XX.XXX.XXX.XXX     UHr            39       51    ppp0

Destination                             Gateway                         Flags         Netif Expire
::1                                     link#1                          UHL             lo0
fd68:826b:73eb:aac::/64                 fe80::bc56:f52b:e100:a834%utun0 Uc            utun0
fd68:826b:73eb:aac:bc56:f52b:e100:a834  link#10                         UHL             lo0
fe80::%lo0/64                           fe80::1%lo0                     UcI             lo0
fe80::1%lo0                             link#1                          UHLI            lo0
fe80::%en0/64                           link#4                          UCI             en0
fe80::21f:5bff:fe38:e158%en0            0:1f:5b:38:e1:58                UHLI            lo0
fe80::%utun0/64                         fe80::bc56:f52b:e100:a834%utun0 UcI           utun0
fe80::bc56:f52b:e100:a834%utun0         link#10                         UHLI            lo0
ff01::%lo0/32                           fe80::1%lo0                     UmCI            lo0
ff01::%en0/32                           link#4                          UmCI            en0
ff01::%en2/32                           link#6                          UmCI            en2
ff01::%utun0/32                         fe80::bc56:f52b:e100:a834%utun0 UmCI          utun0
ff02::%lo0/32                           fe80::1%lo0                     UmCI            lo0
ff02::%en0/32                           link#4                          UmCI            en0
ff02::%en2/32                           link#6                          UmCI            en2
ff02::%utun0/32                         fe80::bc56:f52b:e100:a834%utun0 UmCI          utun0

Any ideas on what I can do to fix or debug these remaining niggles would be amazing?

Update - I have been performing further tests and screen sharing performance is also very choppy.

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