Special note for users with Linksys WRT54G/GL/GS routers, there are severe problems with them when running any P2P app (read for fix)
The following note does NOT apply to WRT54G/GS v5s! Use the latest official firmware (1.00.9+) with those, they do not suffer from this problem.
The default firmware for Linksys (and all replacement firmwares except for the latest DD-WRT and HyperWRT Thibor) have a severe problem where they track old connections for FIVE days, which causes the router to hang when using P2P apps, or any software that generates a lot of connections. DHT only aggravates the situation because of the number of connections it generates.
Linksys has yet to address this issue, but there is a fix. If you use alternative firmware, you can put in a start-up script to fix this problem. DD-WRT and HyperWRT support custom start-up scripts. I am not responsible if you screw up your router, so you do this at your own risk. This page has instructions on recovering a bricked router.:
HyperWRT Thibor (14+) (54G/GL/GS only, excluding hardware revision V5 of 54G/GS)
DD-WRT (v23+)(54G/GL/GS excluding hardware revision V5 of 54G)
If you experience any strange issues or performance problems, clear your NVRAM, and if all else fails, try changing firmwares (but make sure you clear the NVRAM afterwards!)
You should avoid upgrading over a wireless connection, since the connection may drop out and brick the router.
To upgrade the firmware follow the instructions on the download section of Thibor's page if flashing to HyperWRT Thibor, and make sure you download the correct firmware version for your router!
Neither DD-WRT v23+ nor DD-WRT Thibor14+ require these steps, but older versions of HyperWRT tofu/Thibor and DD-WRT do. The following are for HyperWRT tofu and older Thibors.
Go to the web interface (default password is admin) by typing
http://192.168.1.1 into your browser.
Click Administration, then Edit Startup. Put the following commands in the box:
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
echo "600 1800 120 60 120 120 10 60 30 120" > /proc/sys/net/ipv4/ip_conntrack_tcp_timeouts
Click Save, close the window, then click Save settings.
Reboot the router (the Administration page has a Reboot button) and you'll be done.
To upgrade to DD-WRT, follow the instructions on this page. The Right Way to Flash Your WRT54G/GL/GS. The following instructions are for DD-WRT only
Do not use the web interface method as it cuts off part of the commands.
Enable SSH (Admin, Services) as we are going to use the NVRAM method @
http://wrt-wiki.bsr-clan.de/index.ph...s#NVRAM_Method
Login to the router with an SSH client (root/your password).
Put the following commands into the SSH client.
~ # nvram set rc_startup="
> echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
> echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
> echo '600 1800 120 60 120 120 10 60 30 120' > /proc/sys/net/ipv4/ip_conntrack_tcp_timeouts
> "
~ # nvram commit
~ # reboot
The system is going down NOW !!
Sending SIGTERM to all processes.
Note the ' instead of " on the third command line. Using " on the third command line closes the set command (as on last line), meaning that the last command will get cut off prematurely.
Make sure your "Maximum Ports" is set to 4096 on the Management page.
You can check the settings worked by logging in via SSH and viewing the contents of each file as below or using the "nvram get rc_startup" command.
~ # more /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
1
Enjoy instant µTorrent speed increase from pretty much zero on each torrent to full speed!
Thanks frankw for the instructions for DD-WRT
Remember, I am not responsible if you screw up your router, so it's your problem if something goes wrong. However, if something does go wrong, this page has instructions on recovering a bricked ("dead") router.
If you require further assistance with either firmware, please visit HyperWRT.org (the main site does not have the latest builds however), HyperWRT Forum's Advanced Help Section, DD-WRT.org, and DD-WRT's Wiki.
Please do not ask for help with these firmwares on the µTorrent forums.