Dell Networking SONiC MC-LAG se verá afectado cuando el estado de la sesión keepalive se reduzca

Summary: En este artículo, se explica cómo MC-LAG se ve afectado cuando el estado de la sesión keepalive deja de funcionar en SONiC.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.

Symptoms

MC-LAG se ve afectado cuando el estado de la sesión keepalive deja de funcionar en SONiC.
El siguiente estado de MC-LAG se observa en el momento de la sesión keepalive inactiva: 
SONIC-1# show mclag brief
 
Domain ID            : 1
Role                 : active
Session Status       : down
Peer Link Status     : up
Source Address       : 192.168.2.1
Peer Address         : 192.168.2.2
Peer Link            : PortChannel100
Keepalive Interval   : 1 secs
Session Timeout      : 30 secs
Delay Restore        : 300 secs
System Mac           : XX:XX:XX:XX:XX:XX
Mclag System Mac     : 00:00:00:00:00:01
 
 
Number of MLAG Interfaces:1
-----------------------------------------------------------
MLAG Interface       Local/Remote Status 
-----------------------------------------------------------
PortChannel1             up/unknown

Cause

MC-LAG se ve afectado cuando el estado de la sesión keepalive deja de funcionar en SONiC. El keepalive en SONiC está configurado con una comunicación IPv4 L3 similar al enlace de respaldo en OS9 y OS10, que generalmente no afecta el estado de VLT-Portchannel. El estado del enlace entre pares en OS9 y OS10 afectará al estado de VLT-Portchannel en su lugar. Sin embargo, en SONiC, el estado de la sesión keepalive debe estar activo para que MC-LAG esté activo. Para el vínculo keepalive, lleva un latido periódico entre los dispositivos pares MC-LAG y también se utiliza para sincronizar el estado entre los dispositivos pares MC-LAG. A diferencia de SONiC, OS9 y OS10 utilizan el enlace par para sincronizar el estado entre los dispositivos pares de VLT.

Descripción de terminologías de MCLAG

Una vez que el vínculo de la sesión keepalive se desactiva, el estado de MC-LAG en ambos dispositivos pares de MC-LAG se vuelve activo/desconocido debido a la falla de sincronización entre ambos dispositivos pares.

Falla de sincronización entre ambos dispositivos pares

En estado normal
SONIC-1#show version 
 
Software Version  : 4.1.0-Enterprise_Base
Product           : Enterprise SONiC Distribution by Dell Technologies
Distribution      : Debian 10.13
Kernel            : 5.10.0-8-2-amd64
Config DB Version : version_4_1_1
Build Commit      : 93589a15db
Build Date        : Tue Apr 18 17:56:48 UTC 2023
Built By          : sonicbld@sonic-lvn-csg-001
Platform          : x86_64-kvm_x86_64-r0
HwSKU             : DellEMC-S5248f-P-25G-DPB

SONIC-1# show ip interfaces 
Flags: U-Unnumbered interface, A-Anycast IP
-----------------------------------------------------------------------------------------------------------------
Interface            IP address/mask                              VRF                 Admin/Oper     Flags          
-----------------------------------------------------------------------------------------------------------------
PortChannel200       192.168.2.1/24                                                   up/up                         
Vlan636              172.16.0.1/24                                                    up/up                         
SONIC-1# 
SONIC-1# 
SONIC-1# show PortChannel summary 
Flags(oper-status):  D - Down U - Up (portchannel) P - Up in portchannel (members)
----------------------------------------------------------------------------------------------------------------------------
Group               PortChannel                   Type                Protocol          Member Ports
----------------------------------------------------------------------------------------------------------------------------
1                   PortChannel1   (U)            Eth                 LACP                 Eth1/1(P)
100                 PortChannel100 (U)            Eth                 NONE                 Eth1/8(P)
                                                                                           Eth1/9(P)
200                 PortChannel200 (U)            Eth                 LACP                 Eth1/5(P)
                                                                                           Eth1/6(P)
SONIC-1# 
SONIC-1# 
SONIC-1# show mclag brief
 
Domain ID            : 1
Role                 : active
Session Status       : up
Peer Link Status     : up
Source Address       : 192.168.2.1
Peer Address         : 192.168.2.2
Peer Link            : PortChannel100
Keepalive Interval   : 1 secs
Session Timeout      : 30 secs
Delay Restore        : 300 secs
System Mac           : XX:XX:XX:XX:XX:XX
Mclag System Mac     : 00:00:00:00:00:01
 
 
Number of MLAG Interfaces:1
-----------------------------------------------------------
MLAG Interface       Local/Remote Status 
-----------------------------------------------------------
PortChannel1             up/up
SONIC-1# 
SONIC-1# 
SONIC-1# show running-configuration interface PortChannel 1
!
interface PortChannel1 mode active
 switchport trunk allowed Vlan 636
 no shutdown
 mclag 1
SONIC-1# show running-configuration interface PortChannel 100
!
interface PortChannel100 mode on
 switchport trunk allowed Vlan 1-4094
 no shutdown
SONIC-1# show running-configuration interface PortChannel 200
!
interface PortChannel200 mode active
 no shutdown
 ip address 192.168.2.1/24
SONIC-1# 
SONIC-1# 
SONIC-1# ping 172.16.0.3  //IP address assigned to VLAN636 on uplink SW.
PING 172.16.0.3 (172.16.0.3) 56(84) bytes of data.
64 bytes from 172.16.0.3: icmp_seq=1 ttl=64 time=3.26 ms
64 bytes from 172.16.0.3: icmp_seq=2 ttl=64 time=3.47 ms
64 bytes from 172.16.0.3: icmp_seq=3 ttl=64 time=3.21 ms
64 bytes from 172.16.0.3: icmp_seq=4 ttl=64 time=2.84 ms
64 bytes from 172.16.0.3: icmp_seq=5 ttl=64 time=11.1 ms
^C
SONIC-1# 
SONIC-2#show version 
 
Software Version  : 4.1.0-Enterprise_Base
Product           : Enterprise SONiC Distribution by Dell Technologies
Distribution      : Debian 10.13
Kernel            : 5.10.0-8-2-amd64
Config DB Version : version_4_1_1
Build Commit      : 93589a15db
Build Date        : Tue Apr 18 17:56:48 UTC 2023
Built By          : sonicbld@sonic-lvn-csg-001
Platform          : x86_64-kvm_x86_64-r0
HwSKU             : DellEMC-S5248f-P-25G-DPB

SONIC-2# show ip interfaces 
Flags: U-Unnumbered interface, A-Anycast IP
-----------------------------------------------------------------------------------------------------------------
Interface            IP address/mask                              VRF                 Admin/Oper     Flags          
-----------------------------------------------------------------------------------------------------------------
PortChannel200       192.168.2.2/24                                                   up/up                         
Vlan636              172.16.0.2/24                                                    up/up                         
SONIC-2# 
SONIC-2# 
SONIC-2# show PortChannel summary 
Flags(oper-status):  D - Down U - Up (portchannel) P - Up in portchannel (members)
----------------------------------------------------------------------------------------------------------------------------
Group               PortChannel                   Type                Protocol          Member Ports
----------------------------------------------------------------------------------------------------------------------------
1                   PortChannel1   (U)            Eth                 LACP                 Eth1/1(P)
100                 PortChannel100 (U)            Eth                 NONE                 Eth1/8(P)
                                                                                           Eth1/9(P)
200                 PortChannel200 (U)            Eth                 LACP                 Eth1/5(P)
                                                                                           Eth1/6(P)
SONIC-2# 
SONIC-2# 
SONIC-2# show mclag brief
 
Domain ID            : 1
Role                 : standby
Session Status       : up
Peer Link Status     : up
Source Address       : 192.168.2.2
Peer Address         : 192.168.2.1
Peer Link            : PortChannel100
Keepalive Interval   : 1 secs
Session Timeout      : 30 secs
Delay Restore        : 300 secs
System Mac           : XX:XX:XX:XX:XX:XX
Mclag System Mac     : 00:00:00:00:00:01
 
 
Number of MLAG Interfaces:1
-----------------------------------------------------------
MLAG Interface       Local/Remote Status 
-----------------------------------------------------------
PortChannel1             up/up
SONIC-2# 
SONIC-2# 
SONIC-2# 
SONIC-2# 
SONIC-2# show running-configuration interface PortChannel 1
!
interface PortChannel1 mode active
 switchport trunk allowed Vlan 636
 no shutdown
 mclag 1
SONIC-2# show running-configuration interface PortChannel 100
!
interface PortChannel100 mode on
 switchport trunk allowed Vlan 1-4094
 no shutdown
SONIC-2# show running-configuration interface PortChannel 200
!
interface PortChannel200 mode active
 no shutdown
 ip address 192.168.2.2/24
SONIC-2# 
SONIC-2# 
SONIC-2# ping 172.16.0.3
PING 172.16.0.3 (172.16.0.3) 56(84) bytes of data.
64 bytes from 172.16.0.3: icmp_seq=1 ttl=64 time=3.48 ms
64 bytes from 172.16.0.3: icmp_seq=2 ttl=64 time=2.94 ms
^CSONIC-2# 


En estado de problema (Keepalive-link Status Down by Shut down Po200 Member Ports)
SONIC-1# show mclag brief
 
Domain ID            : 1
Role                 : active
Session Status       : down
Peer Link Status     : up
Source Address       : 192.168.2.1
Peer Address         : 192.168.2.2
Peer Link            : PortChannel100
Keepalive Interval   : 1 secs
Session Timeout      : 30 secs
Delay Restore        : 300 secs
System Mac           : XX:XX:XX:XX:XX:XX
Mclag System Mac     : 00:00:00:00:00:01
 
 
Number of MLAG Interfaces:1
-----------------------------------------------------------
MLAG Interface       Local/Remote Status 
-----------------------------------------------------------
PortChannel1             up/unknown
SONIC-1# 
SONIC-1# 
SONIC-1# ping 172.16.0.3
PING 172.16.0.3 (172.16.0.3) 56(84) bytes of data.
64 bytes from 172.16.0.3: icmp_seq=1 ttl=64 time=8.00 ms
64 bytes from 172.16.0.3: icmp_seq=2 ttl=64 time=3.08 ms
64 bytes from 172.16.0.3: icmp_seq=3 ttl=64 time=2.99 ms
64 bytes from 172.16.0.3: icmp_seq=4 ttl=64 time=2.92 ms
64 bytes from 172.16.0.3: icmp_seq=5 ttl=64 time=3.07 ms
^C
SONIC-1#
SONIC-2# show PortChannel summary 
Flags(oper-status):  D - Down U - Up (portchannel) P - Up in portchannel (members)
----------------------------------------------------------------------------------------------------------------------------
Group               PortChannel                   Type                Protocol          Member Ports
----------------------------------------------------------------------------------------------------------------------------
1                   PortChannel1   (U)            Eth                 LACP                 Eth1/1(P)
100                 PortChannel100 (U)            Eth                 NONE                 Eth1/8(P)
                                                                                           Eth1/9(P)
200                 PortChannel200 (D)            Eth                 LACP                 Eth1/5(D)
                                                                                          Eth1/6(D)
SONIC-2# show mclag brief
 
Domain ID            : 1
Role                 : standby
Session Status       : down
Peer Link Status     : up
Source Address       : 192.168.2.2
Peer Address         : 192.168.2.1
Peer Link            : PortChannel100
Keepalive Interval   : 1 secs
Session Timeout      : 30 secs
Delay Restore        : 300 secs
System Mac           : XX:XX:XX:XX:XX:XX
Mclag System Mac     : 00:00:00:00:00:01
 
 
Number of MLAG Interfaces:1
-----------------------------------------------------------
MLAG Interface       Local/Remote Status 
-----------------------------------------------------------
PortChannel1             up/unknown
SONIC-2# 
SONIC-2# ping 172.16.0.3
PING 172.16.0.3 (172.16.0.3) 56(84) bytes of data.
From 172.16.0.2 icmp_seq=1 Destination Host Unreachable
From 172.16.0.2 icmp_seq=1 Destination Host Unreachable
From 172.16.0.2 icmp_seq=1 Destination Host Unreachable
From 172.16.0.2 icmp_seq=1 Destination Host Unreachable
^C
 
 

Resolution

Para que MC-LAG siga funcionando sin ningún problema, el estado del enlace keepalive también debe mantenerse en funcionamiento. El puerto de administración se utiliza normalmente para el enlace keepalive, pero el canal de puerto con la dirección IP asignada se puede utilizar para el enlace keepalive con fines de redundancia. El comportamiento (ese MC-LAG se verá afectado cuando el estado del enlace keepalive se desactiva) que se describe en este artículo de la base de conocimientos se espera en todas las versiones al menos hasta la versión 4.2.0 de SONiC.

Affected Products

Enterprise SONiC Distribution, Dell EMC Networking N3200-ON, PowerSwitch S5212F-ON, PowerSwitch S5224F-ON, PowerSwitch S5232F-ON, PowerSwitch S5248F-ON, PowerSwitch S5296F-ON, PowerSwitch Z9100-ON, PowerSwitch Z9264F-ON, PowerSwitch Z9332F-ON
Article Properties
Article Number: 000213968
Article Type: Solution
Last Modified: 23 Jan 2024
Version:  3
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