I am a linux tech for a network with about 40 linux servers. All of our linux servers seem to hang downloading via http or https. I can't even load sourceforge.net... Our windows and freebsd servers do not have this problem.

Our network is run through hp procurve switches into a cisco pix firewall and into dedicated dsl lines.

All of our linux servers are running either red hat enterprise 4, centos 5, or debian etch.

All have intel gigabit ethernet cards, using the e1000 driver

To clear this issue up, I have tried the following per other forum posts:
1. match duplexing modes and speed settings on servers, the ports on the switches they connect to, the switch ports the firewall connects to, on the pix.
2. disable tcp window scaling
3. reenable and increase tcp window scaling
4 recompile nic card driver using latest stable sources
5. have isp check dsl line for errors
6. check local firewall config(http and https are completely open)
7. have isp check firewall config(http and https are completely open)
8. disable ipv6 support
9. optimize tcp settings(window size, buffers, ...)
10. ran packet sniffing software(wireshark) for any issues
11. tried both static ip and dhcp setup
12. tried different switches & different firewalls

the iptables firewall and selinux are both disabled on all servers...

i run into this problem with any web browser, wget, curl, running updates via. apt-get, yum or up2date... they are all running at least the 2.6.18 linux kernel. we have one box running the 2.4 kernel(has same problem)...

this may not help.

I was having similar problems at home, I needed to change the MTU on the router to 1432.
mind you this was apparent on windows, solaris and linux machines.