User manual
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Operating method:
1.
Enable Ring Group 1: Hello time can be disable too, if it enable, time of sending Hello packet could not be very
fast, or it will influence CPU dealing speed.
2.
Set up Port 7 and 8 of Device 100, 101, 102 and 103 to be Ring Port in Ring Group 1, Network ID is1, Ring Type
is Single; as shown in figure 5-47. Set up Port 7 and 8 of Device 107, 108 and 109 to be Ring Ports in Ring Group
2, Network ID is 2. Ring Type is Chain; as shown in figure 5.7.19.
（
Figure 5.7.18
）
（
Figure 5.7.19
）
3.
Use a wire to connect Port 7 and 8 of Device 107-109 in turn to make a chain. Use a wire to connect Port 7
and 8 of Device 100-103 in turn to make a Single Ring, Then use a wire to connect Port 8 of Device 107 and
Port 7 of Device 109 to normal port of Device 102 and 103. Chain is finished.
：
1. Port can not be trunking setting when it is already Ring port.
2. In the same single ring, identity must be consistent; otherwise it will not built a ring and can not
communicate.
3. All ring ports in the VLAN settings must be TRUNK tagged VLAN member, otherwise can not
communicate.
4. To form tangent ring or other complex rings, should pay attention to the ring identity whether is it consistent, different single
ring identification must be different.
5.7.2 RSTP
The first spanning tree protocol was invented in 1985 at the Digital Equipment Corporation by Radia Perlman.
In 1990, the IEEE published the first standard for the protocol as 802.1D, based on the algorithm designed by
Perlman. Subsequent versions were published in 1998 and 2004, incorporating various extensions.
Although the purpose of a standard is to promote interworking of equipment from different vendors, different
implementations of a standard are not guaranteed to work, due for example to differences in default timer settings.
The IEEE encourages vendors to provide a "Protocol Implementation Conformance Statement", declaring which
capabilities and options have been implemented, to help users determine whether different implementations will
interwork correctly.
Also, the original Perlman-inspired Spanning Tree Protocol, called DEC STP, is not a standard and differs from
the IEEE version in message format as well as timer settings. Some bridges implement both the IEEE and the
DEC versions of the Spanning Tree Protocol, but their interworking can create issues for the network
administrator, as illustrated by the problem discussed in an on-line Cisco document.