max bandwidth-affected-linknumber

By default, the USG6000E supports a maximum of eight links affects the actual bandwidth of a Layer 2 Eth-Trunk interface.

Usage Scenario

The maximum number of links that affect the actual bandwidth of a Layer 2 Eth-Trunk interface directly affects the available bandwidth. If the Layer 2 Eth-Trunk interface works in autonegotiation mode, the interface bandwidth change affects the interface cost.

For example, device A and device B are connected through two Eth-Trunk interfaces. Eth-Trunk 1 has 6 active member links, and Eth-Trunk 2 has 4 active member links. If the bandwidth of each member link is 1 Gbit/s, the total bandwidth of Eth-Trunk 1 is 6 Gbit/s and that of Eth-Trunk 2 is 4 Gbit/s. If device A is the root bridge, Eth-Trunk 1 on device B is the root interface, and Eth-Trunk 2 on device B is the alternate interface. If you run the max bandwidth-affected-linknumber command to set the maximum number of links that affect the actual bandwidth of Eth-Trunk 1 to 3, the available bandwidth of Eth-Trunk 1 decreases from 6 Gbit/s to 3 Gbit/s. If Eth-Trunk 1 works in autonegotiation mode, the available bandwidth decrease affects the interface cost and accordingly affects STP recalculation. However, the bandwidth change does not affect traffic on Eth-Trunk 1 that is still forwarded at a rate of 6 Gbit/s.

After the number of Up member links that determine the Eth-Trunk link bandwidth reaches the upper limit, the STP calculation is not affected even if more member links go Up.

Precautions

The max bandwidth-affected-linknumber command is applicable to only Eth-Trunk interfaces in Layer 2 mode.