TOS is either an 8 bit hexadecimal number or an identifier from /etc/iproute2/rt_dsfield. If they are not equal, then the packet may still match a route with a zero TOS. This key has no associated mask and the longest match is understood as: First, compare the TOS of the route and of the packet. There is also a special PREFIX default - which is equivalent to IP 0/0 or to IPv6 ::/0. If the length of the prefix is missing, ip assumes a full-length host route. PREFIX is an IP or IPv6 address optionally followed by a slash and the prefix length. If TYPE is omitted, ip assumes type unicast.
The multiple routing tables enter the game when policy routing is used. The kernel maintains this table automatically and the administrator usually need not modify it or even look at it. This table consists of routes for local and broadcast addresses.
Values (0, 253, 254, and 255) are reserved for built-in use.Īctually, one other table always exists, which is invisible but even more important. Route tables: Linux-2.x can pack routes into several routing tables identified by a number in the range from 1 to 2^31 or by name from the file /etc/iproute2/rt_tables By default all normal routes are inserted into the main table (ID 254) and the kernel only uses this table when calculating routes. It is not present in normal routing tables. Multicast - a special type used for multicast routing. They are mainly equivalent to local with one difference: such addresses are invalid when used as the source address of any packet. Warning: Route NAT is no longer supported in Linux 2.6.Īnycast - not implemented the destinations are anycast addresses assigned to this host. The addresses to translate to are selected with the attribute via. Destinations covered by the prefix are considered to be dummy (or external) addresses which require translation to real (or internal) ones before forwarding. The local senders get an ENETUNREACH error. The packets are dropped and the ICMP message net unreachable is generated. Without policy routing it is equivalent to the absence of the route in the routing table. If such a route is selected, lookup in this table is terminated pretending that no route was found. Throw - a special control route used together with policy rules. The packets are looped back and delivered locally.īroadcast - the destinations are broadcast addresses. Local - the destinations are assigned to this host. Packets are discarded and the ICMP message communication administratively prohibited is generated. Prohibit - these destinations are unreachable. The local senders get an EHOSTUNREACH error.īlackhole - these destinations are unreachable. Packets are discarded and the ICMP message host unreachable is generated. Unreachable - these destinations are unreachable.
Unicast - the route entry describes real paths to the destinations covered by the route prefix. Ip route is used to manipulate entries in the kernel routing tables. Open the terminal and run the following command ip controls IPv4 and IPv6 configuration and tc stands for traffic control. Iproute2 is usually shipped in a package called iproute or iproute2 and consists of several tools, of which the most important are ip and tc. The /etc/net project aims to support most modern network technologies, as it doesn't use ifconfig and allows a system administrator to make use of all iproute2 features, including traffic control. Most network configuration systems make use of ifconfig and thus provide a limited feature set. They should be deprecated, but most distros still include them.
#HOW TO INSTALL IPROUTE2 UBUNTU MANUALS#
Iproute2 is a collection of utilities for controlling TCP / IP networking and traffic control in Linux.Most network configuration manuals still refer to ifconfig and route as the primary network configuration tools, but ifconfig is known to behave inadequately in modern network environments.
0 kommentar(er)
