Welcome to Nefarious 2, the Evilnet IRC daemon

Current features include:

• A completely rewritten network event engine, which make full use of the asynchronous event engines available in FreeBSD (kqueue) and Solaris (/dev/poll), resulting in dramaticaly improved performance.
• New F: (feature) lines in ircd.conf, and the GET/SET commands allow many settings to be changed dynamically, rather than by with compile- time configuration.
• The new "account" feature added to the P10 protocol, allows people to remain logged in to service bots (i.e., gnuworld) during a netsplit. This means people will not have to login again once the network rejoins.

INSTALLATION

Please see the INSTALL file for installation instructions, for hints on how to best configure your OS for running Nefarious 2 under high load, see the various README. files.

COMPATIBILITY

This version of Nefarious 2 will only work with servers that use the P10 protocol, some of the new features will only work between Nefarious 2 servers.

Nefarious 2 versions after March 22nd/commit b6ac7f6 are by default not backward compatable with SSL server2server links. You must add feature SSL_NOSSLv3 = "FALSE" until all servers are updated.

GENERAL PERFORMANCE HINTS

For platform-specific notes and hints, see the platform-specific sections below. These notes apply to servers that will serve large numbers (thousands) of clients simultaneously. If your server serves a small amount of users, the defaults should work well enough.

• Run an OS that supports an asynchronous network event engine; currently these are FreeBSD (kqueue), and Solaris (/dev/poll); possibly other BSDs will also support kqueue. This will have a dramatic effect on performance.
• Make things as lean as possible: Make your server dedicated to Nefarious 2, disable anything that is not neccesary, and build a custom kernel (where possible).
• Tune kernel parameters as described in the platform-specific sections below.
• With many clients connecting each second, Nefarious 2 will be doing lots of DNS lookups. Make sure that the DNS server(s) in your /etc/resolv.conf are as close as possible, or run a local caching DNS server on your IRC server.

TIME SYNCHRONIZATION

Many things can and will go horribly wrong when the clocks on the servers on your network become (too far) out of sync. It is therefore highly recommended that all servers run a version of ntpd that will keep their clocks from going astray.

INFORMATION HIDING

As per undernet-admins CFV-165, this server contains code that will, by default, hide certain information from ordinary users. If you do not want this, override the default "HIS" feature settings in your ircd.conf.

MORE INFORMATION

For more information on this software, see the included documentation in the doc/ directory.

For general information on Evilnet, visit http://evilnet.github.io/

Happy IRCing!

RUNNING THIS SERVER ON LINUX

If you run Linux 2.6 or above (or 2.4 with appropriate patches), Nefarious 2 can use the epoll family of system calls for much more efficient checks of which connections are active. Most pre-epoll systems will use 100% CPU with 2000 clients; with epoll, a server may use only a few percent of CPU with the same load.

To handle that many connections, the ircd must be started with a high enough file descriptor resource. Check your distribution's docs on how to set the global and per-user limits according to your expected load.

RUNNING THIS SERVER ON FREEBSD

When running on FreeBSD, Nefarious 2 can make use of the kqueue() event engine, which results in much improved performance over the old poll()-based method. kqueue is included in the more recent 4.x releases of FreeBSD.

In order for Nefarious 2 to be able to serve many clients simultaneously, you need to increase the maximum allowable number of open files in the system. To do this, add commands such as the following during your system's boot sequence:

sysctl -w kern.maxfiles=16384 sysctl -w kern.maxfilesperproc=16384

Unless you will be serving thousands of clients simultaneously, you will not need to do the following, unless of course you just can't stand having a system that is not optimized to its limits :)

Build a custom kernel: Make your kernel as lean as possible by removing all drivers and options you will not need. The following parameters will affect performance, they are listed with suggested values only. For more information on what they do exactly, see FreeBSD's documentation.

maxusers 2048 options NMBCLUSTERS=65535 options ICMP_BANDLIM

Also, you may wish to run the following at system startup (from /etc/rc.local, or whichever other method you prefer):

sysctl -w net.inet.tcp.rfc1323=1 sysctl -w net.inet.tcp.delayed_ack=0 sysctl -w net.inet.tcp.restrict_rst=1 sysctl -w kern.ipc.maxsockbuf=2097152 sysctl -w kern.ipc.somaxconn=2048

Created by Sengaia sengaia@undernet.org, July 20 2002.

RUNNING THIS SERVER ON SOLARIS

When running on Solaris, Nefarious 2 can make use of the /dev/poll event engine, which results in much improved performance over the old poll()-based method. Solaris versions 8 and 9 include /dev/poll out of the box, for Solaris 7 you will have to grab and install Patch-ID 106541-21.

In order to increase the number of clients Nefarious 2 can handle, add lines such as the following to /etc/system:

• set hard limit on file descriptors set rlim_fd_max = 16384
• set soft limit on file descriptors set rlim_fd_cur = 8192

For more useful hints see http://www.sean.de/Solaris/soltune.html

Created by Sengaia sengaia@undernet.org on July 20, 2002.