S Series Switches
iStack Technology White Paper
Contents
Contents
1 Feature Introduction ..................................................................................................................... 1
1.1 iStack Overview ............................................................................................................................................................ 1
1.2 Concepts ....................................................................................................................................................................... 2
1.3 iStack Advantages ......................................................................................................................................................... 3
1.3.5 Long-Distance Stacking ............................................................................................................................................. 7
1.3.6 Simplified Networking .............................................................................................................................................. 8
2 Technology Description ............................................................................................................. 10
2.1 Stack Physical Connection .......................................................................................................................................... 10
2.2 Stack Packets .............................................................................................................................................................. 11
2.2.1 Stack Packet Header ................................................................................................................................................ 11
2.2.2 Stack Packet Types .................................................................................................................................................. 12
2.3 Stack State Machine .................................................................................................................................................... 13
2.4 Stack Setup ................................................................................................................................................................. 14
2.5 Member Switch Addition ............................................................................................................................................ 15
2.6 Member Switch Removal ........................................................................................................................................... 17
2.7 Stack Merge ................................................................................................................................................................ 20
2.8 Stack Split ................................................................................................................................................................... 21
2.9.1 MAD Modes ............................................................................................................................................................ 24
2.9.2 MAD Collision Handling......................................................................................................................................... 27
2.9.3 MAD Fault Recovery............................................................................................................................................... 27
2.11 Smooth Upgrade ....................................................................................................................................................... 28
2.12 iStack Packet Forwarding ......................................................................................................................................... 30
2.12.1 Unicast Packet Forwarding .................................................................................................................................... 30
Issue 01 (2013-05-25)
Huawei Proprietary and Confidential
ii
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