From 718e3744195351130f4ce7dbe0613f4b3e23df93 Mon Sep 17 00:00:00 2001 From: paul Date: Fri, 13 Dec 2002 20:15:29 +0000 Subject: Initial revision --- doc/kernel.texi | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 doc/kernel.texi (limited to 'doc/kernel.texi') diff --git a/doc/kernel.texi b/doc/kernel.texi new file mode 100644 index 00000000..b863a1f6 --- /dev/null +++ b/doc/kernel.texi @@ -0,0 +1,48 @@ +@node Kernel Interface, SNMP Support, IPv6 Support, Top +@comment node-name, next, previous, up +@chapter Kernel Interface + +There are several different methods for reading kernel routing table +information, updating kernel routing tables, and for looking up +interfaces. + +@table @samp + +@item ioctl +The @samp{ioctl} method is a very traditional way for reading or writing +kernel information. @samp{ioctl} can be used for looking up interfaces +and for modifying interface addresses, flags, mtu settings and other +types of information. Also, @samp{ioctl} can insert and delete kernel +routing table entries. It will soon be available on almost any platform +which zebra supports, but it is a little bit ugly thus far, so if a +better method is supported by the kernel, zebra will use that. + +@item sysctl +@samp{sysctl} can lookup kernel information using MIB (Management +Information Base) syntax. Normally, it only provides a way of getting +information from the kernel. So one would usually want to change kernel +information using another method such as @samp{ioctl}. + +@item proc filesystem +@samp{proc filesystem} provides an easy way of getting kernel +information. + +@item routing socket + +@item netlink +On recent Linux kernels (2.0.x and 2.2.x), there is a kernel/user +communication support called @code{netlink}. It makes asynchronous +communication between kernel and Zebra possible, similar to a routing +socket on BSD systems. + +Before you use this feature, be sure to select (in kernel configuration) +the kernel/netlink support option 'Kernel/User network link driver' and +'Routing messages'. + +Today, the /dev/route special device file is obsolete. Netlink +communication is done by reading/writing over netlink socket. + +After the kernel configuration, please reconfigure and rebuild Zebra. +You can use netlink as a dynamic routing update channel between Zebra +and the kernel. +@end table -- cgit v1.2.1