eNSP (Huawei Simulator)

Link Aggregation

Advantages

In manual link aggregation, member interfaces are manually configured and added, without the involvement of LACP.
When a large link bandwidth is needed between two directly connected devices but the devices do not support the LACP protocol, manual mode can be used.
There is no need to worry about protocol packet negotiation issues between different vendors.

Disadvantages

When one link fails, the failed link cannot forward data, and the link aggregation group automatically distributes traffic across the remaining two active links. In manual mode, Eth-Trunk can aggregate multiple physical interfaces into a single Eth-Trunk interface to increase bandwidth, and it can detect limited faults such as disconnections in member links within the same aggregation group, but it cannot detect faults such as link-layer failures or incorrect link connections.
- When a single fiber core fails, the port at the receiving end on the normal side may remain UP, resulting in one-way communication. Therefore, in this case, the port matching mode is generally required to be set to adaptive mode.

Advantages

Improves the fault tolerance of Eth-Trunk and provides backup functionality to ensure high reliability of member links

Disadvantages

Interconnecting different vendors may cause interworking exceptions due to differences in protocol packet processing mechanisms.
Moreover, in general: dynamic aggregation should be used together with the port matching mode set to forced, because: if the port matching mode is set to adaptive, then when the physical link quality is poor, the port state may change frequently, and the corresponding aggregation group state will also frequently experience up/down faults.

When interconnecting different vendors, it is recommended to configure the aggregation group as static and set the ports to adaptive mode

Generally speaking, when there are three links in the aggregation, choose max active-linknumber 2. In this way, even if one link goes down, another one can be added in immediately, and there are still 2 links working.

An interface configured with stp edged-port enable does not participate in spanning tree computation; that is, it can both forward BPDUs and receive BPDUs.
disable disables the STP/RSTP/MSTP function. If this command is configured on an interface connecting to a client, this interface disables the STP/RSTP/MSTP function, that is, it neither participates in spanning tree computation nor forwards BPDU packets.
Definition: In RSTP, if a designated port is located at the edge of the entire network, that is, it is no longer connected to other switching devices but directly connected to terminal devices, this kind of port is called an edge port.
Characteristics

The characteristic of an edge port is that once the port goes up, it can directly enter the forwarding state without waiting for the forwarding delay. Therefore, the devices connected to edge ports are terminal devices such as computers, servers, and other devices that need to quickly access the network.
- Scenario 1: Edge ports can be used when connecting terminal devices such as servers, DHCP clients, firewalls, printers, and routers
- Scenario 2: Important servers — to avoid them being blocked when the network topology changes, and to allow them to come online quickly
- Scenario 3: Can be used to connect DHCP clients, allowing them to quickly obtain IP addresses
- Scenario 4: In large networks, switches connecting a large number of terminal PCs can use edge ports, because when a PC powers on, the port connecting to the PC (as a DP) goes UP and enters the forwarding state, and the switch will generate a large number of TC BPDUs, causing the switches in the network to frequently refresh their own MAC address tables.

Generally speaking, enable stp on PC interfaces, because they do not need to participate in spanning tree computation

stp cost is an important parameter used by the spanning tree protocol when electing the root port and the designated port. The smaller the cost, the greater the likelihood of being elected as the root port or designated port. With a cost value as large as stp cost 100000, this port is basically in a logically blocked state; unless the physical links on all other ports of the switch are down, this port may enter the forwarding state.
In plain language, once this is set, it is blocked, because its priority is very low; it will not be activated unless the normal link goes down.

It needs to be configured on the root port. Use the command display stp brief to check which port has the Root status; that one is the root port.

root = root port, alte = alternate port = alternative, desi = designated port = designation

Updating……