Dying gasp Alarm on Huawei OLT

Sometimes on Huawei OLT you can see Dying gasp Alarm (0x2e11a00b).

Since they often occur, most likely they can be seen by running the commands:

display alarm active alarmid 0x2e11a00b
display alarm history alarmid 0x2e11a00b

I will give an example:

ALARM 531377 FAULT MINOR 0x2e11a00b SERVICE QUALITY 2017-12-06 08:19:27+02:00
ALARM NAME : The dying-gasp of GPON ONTi (DGi) is generated
SRVEFF : SA
PARAMETERS : FrameID: 0, SlotID: 5, PortID: 6, ONT ID: 32, Equipment ID:
TL-GP110
DESCRIPTION : The ONT is power off
CAUSE : The power supply of the ONT is abnormal
ADVICE : Check the power supply of the ONT and ensure that the power
supply works in the normal state

These alarms occur when power is lost or the power cord is removed from the ONT, at this moment ONT manages to send the Dying gasp message to the OLT.
Dying gasp is also used on many other devices, for example, to correctly terminate the connection.

Alarm solution 0x2e112007 “The OLT cannot receive expected optical signals from the ONT in four consecutive frames”

Recently noticed that OLT (MA5683T) disables one ONT and reports an alarm “0x2e112007”.

After watching the alarm history:

display alarm history all
display alarm active all
alarm active clear all
display alarm active all

Observed the following:

ALARM 470141 FAULT WARNING 0x2e112007 SERVICE QUALITY 2017-10-19 09:17:50+02:00
ALARM NAME : The distribute fiber is broken or OLT can not receive
expected optical signals from GPON ONT(LOSi)
SRVEFF : SA
PARAMETERS : FrameID: 0, SlotID: 4, PortID: 3, ONT ID: 38, Equipment ID:
I-010G
DESCRIPTION : The OLT cannot receive expected optical signals from the ONT
in four consecutive frames
CAUSE : (1) The fiber is broken
(2) The quality of the optical path is poor
(3) The ONT hardware fails
ADVICE : (1) Check tributary optical fiber connection and backbone
optical fiber orderly, clean the fiber connector and replace
the fiber if necessary
(2) Ensure that the optical attenuation of the optical path is normal
(3) Reset the ONT or replace the ONT
— END

I tried to activate ONT:

interface gpon 0/4
ont activate 3 38
quit

But OLT still turned it off, at different intervals of 1-10 minutes.

Example of viewing the statistics of the number of alarms:

display alarm statistics

Viewing the alarm configuration:

display alarm configuration 0x2e112007

The ONT model was TP-Link GP110 with a signal of -15 for receiving and 2.1-2.7 for sending.
We tried to replace ONT with Alcatel-Lucent I-010G, the signal became -17, and OLT even more often began to turn it off.
Cleaning the connectors and digesting the dividers also did not help.

The problem was in a sagging piece of cable that hung from a very high altitude, after its replacement, the alarm disappeared, and the send signal became stable 2.46.

Limiting access to management of Huawei SmartAX MA5600

For example, to allow to connect to the Huawei SmartAX MA5600 series via telnet only to the specified IP address ranges 192.168.0.100-192.168.0.254 and 172.16.24.1-172.16.24.50 we will connect to the device and go into the configuration mode:

enable
config

And execute the following commands (for non-specified IP access is immediately prohibited):

sysman ip-access telnet 192.168.0.100 192.168.0.254
sysman ip-access telnet 172.16.24.1 172.16.24.50
sysman firewall telnet enable

Similarly for SSH:

sysman ip-access ssh 192.168.0.100 192.168.0.254
sysman firewall ssh enable

And SNMP for example for one IP:

sysman ip-access snmp 192.168.0.100 192.168.0.100
sysman firewall snmp enable

To deny access to the specified subnet, we specify ip-refuse instead of ip-access, for example:

sysman ip-refuse telnet 192.168.1.200 192.168.1.220
sysman firewall telnet enable

On the test, I performed the settings for Huawei SmartAX MA5683T, they are essentially the same for the entire MA5600 series.

Reason for messages “Failure: System is busy, please retry after a while” on Huawei OLT

Once when executing commands in the Huawei SmartAX console, the MA5683T began to notice often the message:

Failure: System is busy, please retry after a while

As it turned out, the reason in my case was Zabbix, which every hour received SNMP levels ONT and drew graphics. SNMP requests from him were packed with packets of 30-50, separately for each port. I solved the problem by increasing the timeout in the Zabbix server configuration and the verification period for more hours, because OLT was slowly issuing information, Zabbix was not available, considered it inaccessible, paused briefly and sent requests again.
Also, in the settings of the Zabbix node, you need to uncheck “Use bulk requests”.

Port isolation on Huawei switches

On the test I’ll take the Huawei Quidway S2326TP-EI and Huawei Quidway S3928P-EI switches, in which the uplink Gigabit Ethernet port 0/0/1 (the Internet comes to it), all other ports are in the same VLAN and you need to prevent them from seeing each other. To do this, execute the port-isolate enable command for each interface (port), except uplink GigabitEthernet 0/0/1.

We connect to the switch through the console or telnet and switch to the mode of elevated privileges:

system-view

We execute the command for interfaces:

interface Ethernet 0/0/1
port-isolate enable
interface Ethernet 0/0/2
port-isolate enable
interface Ethernet 0/0/3
port-isolate enable
etc.
interface Ethernet 0/0/24
port-isolate enable
quit
interface GigabitEthernet 0/0/2
port-isolate enable

For Huawei Quidway S3928P-EI there will be other commands:

interface Ethernet1/0/1
port isolate
interface Ethernet1/0/2
port isolate
...
interface GigabitEthernet 1/1/2
port isolate
interface GigabitEthernet 1/1/3
port isolate
interface GigabitEthernet 1/1/4
port isolate

Leave the interface setup mode:

quit

Let’s leave the regime of elevated privileges:

quit

Save the configuration:

save

Now the ports on which the port-isolate enable command is written do not see the other ports on which this command is also registered, they see only the ports where it is not registered, that is, in our case uplink port GigabitEthernet 0/0/1, and it, as on It does not have this command, it sees all the ports with the command and without.

See also:
Configuring the Huawei Quidway Switch S2326TP-EI
Configuring Port isolation on Cisco
Port isolation on the ZyXEL switch

The solution to the error “Service virtual port has existed already”

I noticed once on Huawei MA5683T when I added the service port for ONT the following error:

Failure: Service virtual port has existed already

As reported by the error, the service port is already registered for this ONT.
In my case, there was simply a misprint in ONT ID, it was accidentally indicated by the wrong one, after specifying the correct service port, it was registered.

And if you need to register several service port for one ONT, then see my article – Adding an ONT with trunk port to Huawei SmartAX MA5683T

Adding an ONT with trunk port to Huawei SmartAX MA5683T

Here is an example of adding ONT so that at the output of the ethernet port all VLANs are tagged.
Suppose OLT is configured for my article – Configuring Huawei SmartAX MA5683T through the console.
ONT for the test I’ll take TP-Link GP110 with the configured mode transparent and off DHCP, well, in fact with other single-port ethernet ONT setting is similar.

Continue reading “Adding an ONT with trunk port to Huawei SmartAX MA5683T”