Ports and trunking

Table 7 Ethernet switch port names

Port number

Port alias

 

 

13

Downlink13

 

 

14

Downlink14

 

 

15

Downlink15

 

 

16

Downlink16

 

 

17

Mgmt

 

 

18

Uplink1

 

 

19

Uplink2

 

 

20

Uplink3

 

 

21

Uplink4

 

 

Port trunk groups

When using port trunk groups between two switches, you can create an aggregate link operating at up to forty Gigabits per second, depending on how many physical ports are combined. The switch supports up to 12 trunk groups per switch, each with up to six ports per trunk group.

The trunking software detects broken trunk links (link down or disabled) and redirects traffic to other trunk members within that trunk group. You can only use trunking if each link has the same configuration for speed, flow control, and auto-negotiation.

Statistical load distribution

In a configured trunk group containing more than one port, the load distribution is determined by information embedded within the data frame. For IP traffic, the switch will calculate the trunk port to use for forwarding traffic by implementing the load distribution algorithm on value equals to modulus of (XOR of last 3 bits of Source and last 3 bits of Destination IP address). For non-IP traffic, the switch will calculate the trunk port to use for forwarding traffic by implementing the load distribution algorithm on value equals to modulus of (XOR of last 3 bits of Source and last 3 bits of Destination MAC address).

Built-in fault tolerance

Since each trunk group is composed of multiple physical links, the trunk group is inherently fault tolerant. As long as even one physical link between the switches is available, the trunk remains active.

Statistical load distribution is maintained whenever a link in a trunk group is lost or returned to service.

Before you configure trunks

When you create and enable a trunk, the trunk members (switch ports) take on certain settings necessary for correct operation of the trunking feature.

Before you configure your trunk, you must consider these settings, along with specific configuration rules, as follows:

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HP 445946-001 Port trunk groups, Before you configure trunks, Statistical load distribution, Built-in fault tolerance