Intel-based Macs: Networking Issues (#5): Another performance solution; Problems connecting to servers
Intel-based Macs: Networking Issues (#5): Another performance solution; Problems connecting to servers
Another solution for increasing network performance Last week we noted a a solution to an issue where Intel-based Macs exhibit inordinately slow TCP/IP performance that involves modifying the delayed_ack parameter of Mac OS X's TCP/IP configuration.
A MacFixIt reader has now put a slightly modified version of this workaround into a Startup Item that will enact the TCP/IP configuration changes at each startup without having to permanently modify any Mac OS X component.
The reader writes:
"For stuff like this I usually prefer (and I think Apple does as well) using a Startup Item if at all possible. Just wanted to let you know that I've posted just such a beast for this Intel Mac network problem over on my blog. The Startup Item is on a disk image which also contains an installer and and uninstaller.
"Here is the post with the link."
Problems with Network browsing In addition to previously reported issues with slow connection and volume mounting times for Intel-based Macs connecting over AFP (Apple filesharing protocol), we've now received word of problems using the network browsing functionality build into Mac OS X.
MacFixIt reader Vesselin writes:
"We just got our Intel-based iMac in our office. Works fine but it is impossible to browse Ethernet or wireless connected PC's - Mac and Windows. Simply, from Connect to Server -> Browse menu it doesn't see network volumes.
In many cases this issue can be resolved if you try connect to the desired network volumes by typing IP address directly (as example sfp://192.168.100.2) in "Server Address" field of the "Connect to Server" menu item under "Go" in the Finder.
Configure port for single VLAN for packet loss We previously reported that Intel-based iMacs sometimes exhibit high packet loss rates over Ethernet connections.
MacFixIt reader Tom Mahoney reports that configuring the port for a single VLANs will eliminate the problem for some routers.
Tom writes:
"Through some testing and packet sniffing, we have identified at least one cause of this issue.
"On Foundry Networks P4802 switches configured with multiple VLANs on the port (as they have to be if you are doing VoIP and data on the same port) the Intel Mac out of the box, will drop between 10% and 50% of all packets from a continuous ping. Packet sniffing shows that the ping requests are going out and the replies are being sent but the Mac will report packet loss.
"Configuring the port for a single VLANs will eliminate the problem. We see no difference in the packets with multiple or single VLANs."
MacFixIt reader Mick is another user reporting packet loss:
"I tested our Intel Mac using ping from the network utility and ran into consistent 80% packet loss in either direction to the Intel iMac 17". My Powerbook G4 1.5 Ghz is running smoothly on the network so I cannot say for certain it isn't the Cisco network configuration. With all the other Macs working so well, it is hard to believe however it is the network. I have reported the problem to Apple for escalation."
More on AirPort issues We continue to report slow operation when using certain wireless security standards, but not others. It appears that the currently shipping Intel-based Macs have issues -- in some cases -- with WPA security. Switching to WEP or WPA-2 may resolve the issue.
We've now received reports of other AirPort-related issues.
MacFixIt reader Lance White writes:
"Last week I purchased a new Intel iMac 20" and now I lose my airport connection every few minutes. Like other readers I'll hit refresh on Safari or just go to the menu bar to res-sync w/ the network. I'm wondering if it's because it's an original Base Station."
Jim Weber adds:
"I too have had peculiar problems with my Airport networks. Using Airport Express at home it is fine - can get on internet immediately and the network shows all out other Macs with Airport cards. However, at the office using a computer to computer Airport network with the file sharing turned on, while I can share files using FileMaker, I cannot establish a visible network connection to the from my Powerbook to the iMac to see its hard disk. Very weird."
Feedback? Late-breakers@macfixit.com.
Previous coverage:
- Intel-based Macs: Slow network connections (#4): Terminal-based workaround
- Intel-based Macs: Slow network connections (#3); Changing wireless security settings; more
- Intel-based Macs: Slow network connections
- Intel-based Macs: Slow AFP connections
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