I have an issue with a particular client that is running a Cisco 871 Router. It does the NAT as well as IDS functions. The problem has been happening is that Mac users cannot get upload speeds faster than about 3.0kb/s to most FTP sites. I can connect and upload just fine with a PC. The Macs can download at normal speed from the same sites, but, not upload. It seems to occur on about half of the FTP sites that they use. I have ruled out the machines as the problem, the ISP says it isn't doing any filtering. The only thing I can think of would be something with the router configuration. I have attached the important parts of the config. If anyone could give me some suggestions I would greatly appreciate it.
What ftp client software are those MACs using? Fetch? Have you tried different ftp client for them? What OS version are those MAC running? Patch up-to-date?
I don't think there's anything wrong with your config, since you're able to ftp upload/download just fine. About the MAC, I would think that it's more of the application issue than the router config.
Take a look at these links, and try out different ftp client to see if it helps.
Thanks for your reply. I have tried 3 different FTP clients on both 10.4 and 10.5 systems fully patched: Transmit, Filezilla, and the command line FTP in OSX. All 3 do the same thing. One interesting note when I tried the command line FTP tonight it would transmit about 5-10kb then say stalled for about 30 secs then transmit 5-10kb, stall, etc.
I even took over my Powerbook to the clients office and it did the slowdown on upload then I took it over to another client that has the same ISP, router model/config, and it worked fine.
No PPPOE. It is a burstable T-1 with ethernet hand-off to the Cisco 871.
The clients that I am concerned about and have been testing are on vlan1. I haven't checked the other vlans. I figured they would do the same thing.
Thanks, I removed it earlier and that didn't help the problem and put it back it. I think it was part of the initial config that the SDM software puts on.
You might want to try this if you've not yet tried already:
Also, if your MAC is FTPing using Passive mode, then try disabling it.
I don't know that I could force passive versus active because this is the client end I am having problems with. I can connect to and upload to some servers using passive mode, others won't work.
I found that if I remove the following lines from the config I can upload at normal speeds from the Macs:
ip inspect name SDM_LOW tcp
ip inspect name SDM_LOW ftp
I have to remove both for it to work if I mleave one of the two in it doesn't work.