Smart Link is a solution that provides reliable and high efficiency of backup and fast handover mechanism for dual uplink networks. Through the implementation, it can provide reliable protection for operators. Here, we take Huawei MA5680T as example to illustrate the application of the Smart Link solution in the access network.
For the dual homing networking, the Smart Link implements redundant backup and fast transmission, achieving high reliability and guarantee the high speed of convergence. Meanwhile, as a supplement to Smart Link, the Monitor Link solution was introduced to monitor the uplink, thereby making the backup function of Smart Link more mature.
Smart Link and Monitor Link features related to Huawei MA5680T and uplink network devices, for dual homing networking (double attributable to the uplink of the IP network) scene. Upstream network devices (such as routers) need to have functions that support Monitor Link and Smart Link.
Smart Link and Monitor Link are solutions proposed by Huawei, at the moment, this technology only can be supported by Huawei equipment.
Related concepts of Smart Link:
Smart Link protection group:
Smart Link protection group with two interfaces, one is master port, the other is slave port. Under normal circumstances, there is only one port in forwarding (ACTIVE) state, the other port is blocked, and is in the STANDBY state. When forwarding state port fails, Smart Link group will automatically congest the port, and block the switch port that was in standby to the forwarding state.
Master port, also called Work port, it is also a Smart Link, when both ports are in the standby state, the main port will priority switch to the forwarding state.
Slave port is also called protect port, it is also a Smart Link, when both ports are standby, main port will priority switch to the forwarding stat, slave port will remain in the standby state.
When Smart Link occurs link switching, the original published items will not be applicable to the new network topology, and need uplink to upper layer convergence devices, to upgrade MAC table and ARP table. At this time, Smart Link can send a notification message to notify other devices in the network address table of refresh operation. This is Flush message.
Working principle of the smart link feature
Related concepts of Monitor Link:
Monitor Link Group
Monitoring link group, consists of both the uplink and downlink. A group contains one uplink and several downlinks.
Composition of a monitor link group
If uplink fails, that is to say Monitor Link group is broken, and the downlink of this group will be blocked forcibly.
Downlink failure neither affect uplink nor affect downlink.
Smart Link has two working modes: Active-standby working mode and loading sharing working mode.
The differences between them are: In the Active-standby working mode, the two ports are open at the same time, but only master port is active, and can forward data, while the slave port is blocked and keep on standby.
Working mode of a smart link protect group
In the loading sharing working mode, open the two ports of link, if both are normal, data forwarding through two ports to realize the loading sharing.
Load sharing working mode of a smart link protect group
1. configure Smart Link Protection Group
Using “protect-group” to build a Smart Link protection group. The operation mode of protection group is Active-standby working mode or loading sharing working mode.
When configuring the Smart Link protection group, you need to set “eth-nni-port” as the protection object, Smart Link characteristic cannot be supported by other operation mode of type.
The keyword of “smart-link” represents active-standby working mode. Under this mode, open the links at the same time, shut the standby state to make it only have active forwarding data.
The keyword of “smart-link load-balance” represents loading sharing working mode. Under this mode, open the links at the same time for load sharing to improve the use rate of links.
2. Using “protect-group member” command to add protection members to the Smart Link protection group, at the same time, you should add the operation members first.
3. Using “protect-group enable” command to enable the smart link protection group.
After building a protection group, protection group default state is disabled, you need to enable the protection group.
4. Checking the protection group information
Using “display protect-group” command to check the protection group information and all members’ information.
5. Configuring the sending methods of Flush message
When protection group business switch occurs, the original published items will not apply to the new network, you need to update the entire network of MAC table and ARP table. At this time, the protection group will send flush message to notify other equipment to refresh MAC table and ARP table.
Using “flush send” command to configure the sending parameters of flush message of the protection group, including control VLAN and password.
If the Flush message sending parameters are not configured, no Flush message will be sent when the protection group business is switched.
If the protection group is not in the control VLAN, Flush message will not be sent.
The opposite terminal equipment must support receiving Flush message and enable the receive function of Flush message in corresponding terminal.
Using the “display flush receive” command to check the port on which the Flush message is received and the receive parameters of the Flush message.
You can choose to use “load-balance instance” command to configure the loading sharing parameters of the protection group.
Loading sharing parameters determine the work members and protection members carrying different instances of STP, and due to the mapping relationship between VLAN and STP instance, actually determines the load modes of different VLAN.
Only when Smart Link protection group is in loading sharing working mode, can support configuration loading sharing parameters.
This command is used to configure the protection members to carry on STP instance, unspecified of STP instance is carried on members of the work. The parameters of the load sharing are based on the configured instances of STP and can through “instance vlan” command to configure the mapping relationship of VLAN and STP instance.
Optionally configure Monitor Link group
Monitor Link group and Smart Link protection group generally used in combination, which is used for monitoring uplink to make Smart Link redundancy backup function more perfect.
Working principle of the monitor link feature
Monitor Link group is generally configured on the upper level devices (such as routers) with the Huawei MA5680T docking, and linked to the Smart Link protection group.
Only when use Huawei MA5680T/MA5683T as upper level device docking with OLT can configure Monitor Link on Huawei MA5680T/MA5683T and used to monitor the cascading of the uplink OLT, otherwise, it makes no sense.
Network application of the smart link and monitor link features
1.Using “monitor-link group” command to build a monitor group and enter the monitor group mode.
Monitor group include one uplink port and several downlink ports, when the uplink port fails, close the downlink port to make downstream device detect the link failure, and switch to normal link.
2.Using “member port” command to add monitor members to monitor group.
3.The uplink of monitor group can be ordinary Ethernet port, protection group of master port and aggregation group of master port. But the downlink of monitor group can only be ordinary Ethernet port.
4.Using “display monitor-link group” command to check the detail information of the monitor group.
E. g.: Through the GIU double uplinks, the two uplink ports 0/19/0 and 0/19/1 on the GIU can be configured as members of Smart Link protection group 2, where the 0/19/0 port is the work port, 0/19/1 port is the protection port. The work mode is the loading sharing working mode.
Among them, the STP instance of the working port is 1(100-110 VLAN).
STP instance ID for protecting port is 2(120-130 VLAN)
Control VALN of Flush message is 10 and the password is abc.
huawei-lib-MA5680(config)#stp region-configuration huawei-lib-MA5680(stp-region-configuration)#instance 1 vlan 100 to 110 huawei-lib-MA5680(stp-region-configuration)#instance 2 vlan 120 to 130 huawei-lib-MA5680(stp-region-configuration)#active region-configuration STP actives region configuration,it may take several minutes,are you sure to active region configuration? [Y/N][N]y huawei-lib-MA5680(stp-region-configuration)#quit huawei-lib-MA5680(config)#protect-group 2 protect-target eth-nni-port workmode smart-link load-balance huawei-lib-MA5680(config-protect-group-2)#protect-group member port 0/19/0 role work huawei-lib-MA5680(config-protect-group-2)#protect-group member port 0/19/1 role protect huawei-lib-MA5680(config-protect-group-2)#load-balance instance 2 huawei-lib-MA5680(config-protect-group-2)#flush send control-vlan 10 password simple abc huawei-lib-MA5680(config-protect-group-2)#protect-group enable huawei-lib-MA5680(config-protect-group-2)#quit
After mastering the related concepts and through the above steps: configure the Smart Link protection group, the sending mode of Flush message……Then it can provide reliable protection for the operator's network. Hope this article can help you and solve the related problems.