Is the network affected after LLDP is configured on an S series switch


S series switches (except the S1700) use LLDP to discover link information, which does not affect the network.

Other related questions:
Are services affected after a CSS composed of S series modular switches splits
When a CSS splits, the two devices work independently, and inter-chassis services are interrupted. If MAD is configured, the physical interfaces of one device will be shut down, and services on the interfaces are interrupted.

How do stacks of S series fixed switches affect networks
After S series fixed switches set up a stack, they function as one switch on a network and do not affect the network services and functions. Stacks simplify the network management, and can also be associated with Eth-Trunks to improve network reliability and bandwidth usage.

Configurations that affect ARP entry updating on S series switches
S series switches (except S1700 switches) use ARP messages to dynamically learn and update dynamic ARP entries, which can be overwritten by static ARP entries. Dynamic ARP entries have an aging mechanism. When a dynamic ARP entry expires, the device sends aging detection packets to the corresponding host. If the device receives a response from the host within the specified number of detection times, the ARP entry is updated. If not, the ARP entry is deleted. In addition to aging parameters of dynamic ARP entries, some configurations on the device may affect the aging and updating of dynamic ARP entries. The following lists some common factors. MAC address-triggered ARP update (not supported by S1720, S2720, S275x, or S5700LI fixed switches) By default, the aging time of MAC address entries is 5 minutes, and the aging time of ARP entries is 20 minutes. In certain scenarios, MAC entries are updated, but the ARP entries are not updated accordingly, affecting user services. If this occurs, run the mac-address update arp command to enable the MAC address-triggered ARP update function. After the configuration, when the outbound interfaces in MAC address entries change, the outbound interfaces in ARP entries are updated, so that user services will not be interrupted. Spanning Tree Protocol (STP) By default, when the device receives a Topology Checksum (TC) packet of STP, it ages or deletes the corresponding ARP entry. If the STP convergence mode is fast, the device deletes the corresponding ARP entry when receiving a TC packet. If the STP convergence mode is normal, the device rapidly ages the corresponding ARP entry when receiving a TC packet, that is, the device sets the remaining lifetime of the ARP entry to 0. If the number of detection times for aging out the ARP entry is greater than 0, the device carries out aging detection of the ARP entry. If STP is deployed for a network, you are advised to configure the device interface directly connected to user terminals (such as hosts) as an edge port and enable the Bridge Protocol Data Unit (BPDU) protection function. If not, when a large number of TC packets are generated, the convergence speed of the STP network topology will be reduced, and the updating and maintenance of ARP entries will be affected, which will have an impact on user services. To prevent the device from aging or deleting ARP entries when receiving TC packets, run the arp topology-change disable command to disable the TC packet response function. You are advised to enable the MAC address-triggered ARP update function at the same time. Strict ARP learning After strict ARP learning is enabled, the device learns only the ARP Reply packets in response to the ARP Request packets sent by itself. ARP-CPCAR By default, each type of protocol packets has a default CPCAR value. The CPCAR values of some types of protocol packets need to be adjusted based on service specifications and users' network environments. When a lot of users connect to the device but the CPCAR values of the ARP Request packets and ARP Reply packets are small, ARP packets can be lost. (To check whether ARP packets are lost, run the display cpu-defend statistics all command.) This will affect ARP entry learning and updating. In this case, you can adjust the CPCAR values of ARP packets to proper values. Improper CPCAR settings will affect services on your network. It is recommended that you contact Huawei engineers before adjusting the CPCAR settings. When ARP attacks occur, the learning and updating of dynamic ARP entries will also be affected. In this case, you are advised to find out the attack source and configure appropriate attack defense functions.

How to configure LLDP on S series switches
On Huawei S series switches (except the S1700), LLDP can be enabled globally or on a specified interface. For example: 1. Enable LLDP globally. [HUAWEI] lldp enable 2. Enable LLDP on GigabitEthernet0/0/1 of SwitchA. [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] lldp enable

Is LLDP compatible with CDP on S series switches
On Huawei S series switches (except the S1700), LLDP is compatible with similar protocols from other vendors to obtain status information about non-Huawei devices. For example, LLDP is compatible with CDP. The configuration procedure is as follows: 1. Enable LLDP globally. [HUAWEI] lldp enable 2. Configure CDP-compatible LLDP on an interface. [HUAWEI] interface GigabitEthernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] lldp compliance cdp receive

If you have more questions, you can seek help from following ways:
To iKnow To Live Chat
Scroll to top