Windows 2003 IIS 6.0 FTP problem

I had a problem start about a month ago. I did some small network changes. Anyway my configuration is:

Windows 2003 as domain controller with active directory

2 Network cards:
192.168.0.1 (255.255.255.0 subnet) set for LAN access feeding gigabit switch
10.0.0.1 (255.0.0.0 subnet) feeding a router for WAN access

Server is running RRAS with NAT/Basic firewall for the LAN/WAN routing

Server running IIS 6.0 with FTP server.

Reading there are some IIS 6.0 / RRAS - NAT issues. I had firstly NOT installed KB898060. This caused transfers to hang near the end. Since installing KB898060 transfers just get closed near the end but still incompleted (so its better but not right).

#Software: Microsoft Internet Information Services 6.0
#Version: 1.0
#Date: 2005-12-31 23:02:25
#Fields: time c-ip cs-method cs-uri-stem sc-status sc-win32-status
23:02:25 x.x.x.x [1]USER anonymous 331 0
23:02:31 x.x.x.x [1]PASS mail@mail.com 230 0
23:03:41 x.x.x.x [1]sent /download.test 426 59
23:05:16 x.x.x.x [1]QUIT - 426 0

If I try really small files it works 100%.

Any ideas?

Thanks

 

Sounds like a MTU issue on one of the routers on you LAN or on the WAN. If MTU is set lower that 1496 then packets fragment and large uploads and downloads won't complete.
What kind of connection do you have to the internet?
What kind of routers do you use on the LAN?

 

Hi Bob,

Both NICs have been set for 1500 MTU by TCPIP optimizer. Any test I run from a workstation or the server says my connection is 100% optimised for 1500 MTU.

Connection to the internet is ADSL 24000/1000 via a Draytek 2600V ADSL VoIP router on the 10.0.0.1 NIC. I am using PPPoA on the router.

Files like 100MB still have about 3MB to go. Smaller files then have a lot less. A file of under 2MB (certainly 1.x MB) go straight through.

No problem also accessing or downloading files on the server, its just IIS 6.0

I am testing a trial version of ws_ftp server, it works 100%. Its some issue with RRAS using NAT/Basic Firewall and IIS.

Thanks!

Dave