What kind of line connection between routers and switches?With cable is
twisted-pair cable, generally we use now for five classes or super five kind of twisted pair.
twisted-pair cable is A 8 core two two-phase stranded copper wire, so called twisted-pair cable
T - 568 using A (A line) and T - 568 - B (B) two interface
T - 568 - A interface order is white, green, green, white, orange, blue, white and blue, orange, white, brown, brown
T - 568 - B order is white, orange, orange, white, green, blue, white, blue, green, white, brown, brown
we now use TCP/IP protocol actually only use eight lines of four followed by 1, 2, 3, 6 (arrange: in the wire core color to orange white, orange, green, white, green) another 4 root without don't meet all have no effect.Interconnect
two machines can use two ways, 1 use switches to make two lines, for the type B, orange white, orange, green and white, blue, blue and white, green, brown, white, brown.After making good connection and switch to the machine, set the IP or gain can be automatically.
2 use cross line made A thread end USES adopt type A, type B end and side: orange, white, orange, green and white, blue, blue and white, green, brown, white, brown, on the other side: green and white, green, orange, white, blue, white, blue, orange, brown, white, brown, nic set IP access two machines can direct connection to the router's Ethernet port and
switches as A connection of
cable line sequence is divided into two kinds: 568 A and 568 B.
standard 568 a line sequence: 1 - green and white, 2 - green, 3 - orange white, 4 - blue, 5 - blue and white, 6 - orange, white 7 - brown, 8 - brown;
standard 568 b line sequence: 1 - orange white, 2 - orange, 3 - green and white, 4 - blue, 5 - blue and white, 6 - green, white 7 - brown, 8 - brown;
AA line is straight line, the same at both ends of the cable are using the same thread sequence;AB is the intersection line, the same line of two paragraphs using different thread.That is, both ends of a network cable to use 568 a or 568 b is a straight line;One end on both ends of the cable, with 568 a, 568 b is cross the line.In practice generally use 568 b, that is generally considered to be the 568 b to electromagnetic interference shielding is better.
between different devices with straight line, with a cross line between the same equipment.For example:
switches and routers level it needs to be even with straight line;With a cross line between switches and switch;With direct connections between switches and PC;With a cross line between routers and switches (router can be seen as more than one port of the PC.Switches is equipment on the second floor, the router is three layer devices);ADSL cats can be seen as is a small router, ADSL cats and PC connection with cross line.
straight line used to connect computers and the switch (or HUB), routers and switches (or HUB).
cross line used to connect computers and computer, the computer and the router.Cross the line do not often use
a ribbon cable order from left to right in turn as follows: white, green, green, white, orange, blue, white and blue, orange, white, brown, brown.
568 b is: white orange, orange, white, green, blue, white, blue, green, white, brown, brown.
so-called cross line is to point to: one end is 568 a standard, on the other side is 568 b standard twisted-pair cable.Straight line is to point to: both ends is 568 a or 568 b standard twisted-pair cable.Many friends, by the way, when doing the RJ45 head, just order one to one correspondence guarantee at the ends of the line, is not in accordance with the 568 a / 568 b wire standard to do it.It can connect network, but this line of anti-jamming is very poor, often appear, such as the transmission speed is slow, stand or fall of network.Hope everyone when doing the cable must be in accordance with the standard, and according to the practical engineering experience cable length is not less than 1.5 meters, best this to improve the stability of the network is very necessary!
let's look at how to correctly choose straight wire and twisted pair.When the following equipment interconnection, need to use direct connections: 1.
will switch or HUB connected to the router;
(2) computer (including server and the workstation) connected to the switch or HUB.
and these devices connected, the need to use cross line: 1
.Through UPLINKS mouth connection between switches and switch;
2.The HUB connected to the switch;
3.Connection between the HUB and the HUB;
4.Two PCS directly connected;
5.The router interface with other router interface connection;
6.The Ethernet interface of ADSL Modem is connected to the PC network card interface.Same layer device connected with the