False alarm...my iMac lost Internet connectivity again this afternoon, although it took nearly three days this time. The only change in configuration was that the Energy Saver was set to 3 hours, vice Never. However, this time IE ALSO lost Internet connectivity, and ping failed to resolve the URL, so effectively I lost ALL Internet connectivity this time. A simple reboot restored service. I've turned off iSync again, to see if I'll get three more days of connectivity.
Well, another nearly three days and another burp. Even with everything turned off (iSync, iDisk, SETI, Missing_Sync) that potentially could be affecting the network, the problem persists. It hit again last night. While it took another week, this also hit my other Mac (running 10.2.8 ), although about six hours later than my Panther running iMac burped. As usual, IE continued to access the Internet normally.
I thought I'd share some feedback I just got from a helpful Aussie this morning. He suggested I try changing the MTU setting on my affected Macs to reduce the maximum size of the TCP/IP packets from 1500 to 1492.
Here's what he proposed specifically. First, open Terminal and run the following to see what the current packet size is set to:
ifconfig en0 | sed -ne 's/.*mtu\\ //p;s/[iems].*//'
If that returns 1500, he suggested changing it to 1492. Apparently there's a known problem with DSL Routers running PPPoE with the packet size set to 1500. To change the packet size on my affected Macs, he suggested running the following in Terminal:
sudo ifconfig en0 mtu 1492
If I were connecting via AirPort, I'd enter en1 vice en0 above. Although he didn't say so, it appears I'll have to enter this every time I reboot the computer, or make a permanent change by hacking a startupitems network file, which I'm not comfortable doing.
The open question for me is what impact changing the maximum packet size on one Mac will have on other Macs/Windows PCs/printers on the local network which presumably will retain the default 1500 MTU setting? Can anyone comment?
Well, the saga continues. I changed the MTU packet size to 1492 as proposed, but it had no effect. Again this evening, my Apple apps all lost Internet connectivity, even, again, as Internet Explorer continued surfing away.
Well, the saga continues. I changed the MTU packet size to 1492 as proposed, but it had no effect. Again this evening, my Apple apps all lost Internet connectivity, even, again, as Internet Explorer continued surfing away.
That is very strange. What about other web browsers (omniweb, netscape, and such). Also, is IE really still accessing the web, and not just using pages out its catch?
Well, my Apple apps lost Internet connectivity again tonight, so I checked some website pages I know weren't in my cache in Internet Explorer. They all worked fine. So, it's clear that whatever is affecting Safari, iSync, iDisk is not affecting Internet Explorer. I also confirmed that FTP wasn't working during this latest burp.
Of course, a simple reboot and all's well again for a couple more days.
Why do I continue to post on this issue? Because I'm at a complete lost as to what's causing it. I'm also hoping that some Apple/Safari folks might read it in passing just to see if the symptoms ring any bells for them. Remember, this is happening on a pristine installation of Panther on a summer 2003 17" iMac connected to a DSL modem. If I set the computer to never sleep, it recurs every day or two. If I set it to sleep after three hours of inactivity, it seems to stretch out to two to three days. Internet Explorer never loses its connection, only the Apple apps (including FTP).
Try entering something else like "earthlink.net" in your search domains field, at least put something.
You isp may have changed some requirement. If your router has the feature, try turning on mac cloning.
Try setting your router to refresh it's DHCP lease according your isp's specs.
Some routers allow all pc's on the network to appear to the ISP as one. This is called NAT (network address translation)
Try setting your router to acquire a DHCP address. and set IT to auto assign the DHCP addresses to each PC.
Try turning off your firewall while doing these trials.
If this is an older router, maybe consider a newer one, I use a belkin, but just about any will work. You can get a 802.11b wireless with 4 ports for about 80 bucks.
I had some similar problems with my cable isp, and have found that DSL can sometimes be more problematic. Cable/DSL providers often change setting on thier end without notice, that do not effect most PC's running MS OS's, but effect a lot of Macs. I found that the modern DSL/Cable router isolates you from a lot of that.
if you look at Apple's Airport discussions, there are about 4 threads concerning lapsed AEBS connectivity and potential issues w/ the guts of Panther and OS X. I've just had it trying to work around the lapsed wireless and have gone back to Cat5. I have no problems w/ the hardwired connection, but my AEBS connectivity is a nightmare. I suppose that a fix might happen in the next iteration of Panther... in a way, it's nice to know that Apple is human, too.
Well, after many months, I think the problem with my Mac losing its Internet connection in Safari/Mail/other Apple Internet apps (although not always Internet Explorer) is resolved. I've replaced my SpeedStream 5660 ADSL router with a new Zoom ADSL X5 modem/router. Since I installed this router last Friday, my iMac's Internet connection has been rock solid, so I've turned everything back on, including IP version 6 and my iDisk. Hopefully, this is the conclusion of a very frustrating issue. 8)
Well, after many months, I think the problem with my Mac losing its Internet connection in Safari/Mail/other Apple Internet apps (although not always Internet Explorer) is resolved. I've replaced my SpeedStream 5660 ADSL router with a new Zoom ADSL X5 modem/router. Since I installed this router last Friday, my iMac's Internet connection has been rock solid, so I've turned everything back on, including IP version 6 and my iDisk. Hopefully, this is the conclusion of a very frustrating issue. 8)
Comments
This is very frustrating.
Here's what he proposed specifically. First, open Terminal and run the following to see what the current packet size is set to:
ifconfig en0 | sed -ne 's/.*mtu\\ //p;s/[iems].*//'
If that returns 1500, he suggested changing it to 1492. Apparently there's a known problem with DSL Routers running PPPoE with the packet size set to 1500. To change the packet size on my affected Macs, he suggested running the following in Terminal:
sudo ifconfig en0 mtu 1492
If I were connecting via AirPort, I'd enter en1 vice en0 above. Although he didn't say so, it appears I'll have to enter this every time I reboot the computer, or make a permanent change by hacking a startupitems network file, which I'm not comfortable doing.
The open question for me is what impact changing the maximum packet size on one Mac will have on other Macs/Windows PCs/printers on the local network which presumably will retain the default 1500 MTU setting? Can anyone comment?
Originally posted by Dave Marsh
Well, the saga continues. I changed the MTU packet size to 1492 as proposed, but it had no effect. Again this evening, my Apple apps all lost Internet connectivity, even, again, as Internet Explorer continued surfing away.
That is very strange. What about other web browsers (omniweb, netscape, and such). Also, is IE really still accessing the web, and not just using pages out its catch?
Of course, a simple reboot and all's well again for a couple more days.
Why do I continue to post on this issue? Because I'm at a complete lost as to what's causing it. I'm also hoping that some Apple/Safari folks might read it in passing just to see if the symptoms ring any bells for them. Remember, this is happening on a pristine installation of Panther on a summer 2003 17" iMac connected to a DSL modem. If I set the computer to never sleep, it recurs every day or two. If I set it to sleep after three hours of inactivity, it seems to stretch out to two to three days. Internet Explorer never loses its connection, only the Apple apps (including FTP).
You isp may have changed some requirement. If your router has the feature, try turning on mac cloning.
Try setting your router to refresh it's DHCP lease according your isp's specs.
Some routers allow all pc's on the network to appear to the ISP as one. This is called NAT (network address translation)
Try setting your router to acquire a DHCP address. and set IT to auto assign the DHCP addresses to each PC.
Try turning off your firewall while doing these trials.
If this is an older router, maybe consider a newer one, I use a belkin, but just about any will work. You can get a 802.11b wireless with 4 ports for about 80 bucks.
I had some similar problems with my cable isp, and have found that DSL can sometimes be more problematic. Cable/DSL providers often change setting on thier end without notice, that do not effect most PC's running MS OS's, but effect a lot of Macs. I found that the modern DSL/Cable router isolates you from a lot of that.
Hope some of that helps.
Originally posted by Dave Marsh
Well, after many months, I think the problem with my Mac losing its Internet connection in Safari/Mail/other Apple Internet apps (although not always Internet Explorer) is resolved. I've replaced my SpeedStream 5660 ADSL router with a new Zoom ADSL X5 modem/router. Since I installed this router last Friday, my iMac's Internet connection has been rock solid, so I've turned everything back on, including IP version 6 and my iDisk. Hopefully, this is the conclusion of a very frustrating issue.
Congrats.