[logs][swss] Logs show "cannot stat /proc/sys/net/mpls/conf/Ethernet0/input"

[alexrallen]

Description

Receiving error log during switch boot.

Steps to reproduce the issue:

1. Install SONiC latest master via ONIE
2. Boot switch and check log

Describe the results you received:

This error is shown for all port interfaces during the port initialization.

Dec 22 04:27:03.361056 r-bulldog-03 INFO swss#/supervisord: intfmgrd sysctl: cannot stat /proc/sys/net/mpls/conf/Ethernet0/input: No such file or directory

Describe the results you expected:

No error log.

Output of show version:

SONiC Software Version: SONiC.master.244-3aec72879_Internal
Distribution: Debian 11.2
Kernel: 5.10.0-8-2-amd64
Build commit: 3aec72879
Build date: Wed Dec 22 08:30:03 UTC 2021
Built by: sw-r2d2-bot@r-build-sonic-ci02-241

Platform: x86_64-mlnx_msn3420-r0
HwSKU: ACS-MSN3420
ASIC: mellanox
ASIC Count: 1
Serial Number: MT2019X13878
Model Number: MSN3420-CB2FO
Hardware Revision: A1
Uptime: 22:05:10 up  5:42,  5 users,  load average: 1.11, 1.01, 0.78

Docker images:
REPOSITORY                                         TAG                             IMAGE ID       SIZE
docker-platform-monitor                            latest                          3179b3bfa4a2   809MB
docker-platform-monitor                            master.244-3aec72879_Internal   3179b3bfa4a2   809MB
docker-teamd                                       latest                          2f47d005bb95   436MB
docker-teamd                                       master.244-3aec72879_Internal   2f47d005bb95   436MB
docker-syncd-mlnx                                  latest                          cc4d31e33915   1.01GB
docker-syncd-mlnx                                  master.244-3aec72879_Internal   cc4d31e33915   1.01GB
docker-orchagent                                   latest                          5c891ff8f214   455MB
docker-orchagent                                   master.244-3aec72879_Internal   5c891ff8f214   455MB
docker-dhcp-relay                                  latest                          c646bc83cc8c   436MB
docker-sonic-telemetry                             latest                          606f26ae194f   511MB
docker-sonic-telemetry                             master.244-3aec72879_Internal   606f26ae194f   511MB
docker-sonic-mgmt-framework                        latest                          7c86fd946748   578MB
docker-sonic-mgmt-framework                        master.244-3aec72879_Internal   7c86fd946748   578MB
docker-snmp                                        latest                          546605aaf36c   465MB
docker-snmp                                        master.244-3aec72879_Internal   546605aaf36c   465MB
docker-sflow                                       latest                          68f7233b21a9   436MB
docker-sflow                                       master.244-3aec72879_Internal   68f7233b21a9   436MB
docker-router-advertiser                           latest                          dafc3d1fb775   423MB
docker-router-advertiser                           master.244-3aec72879_Internal   dafc3d1fb775   423MB
docker-nat                                         latest                          47bf92fce979   438MB
docker-nat                                         master.244-3aec72879_Internal   47bf92fce979   438MB
docker-mux                                         latest                          b68969e05d75   475MB
docker-mux                                         master.244-3aec72879_Internal   b68969e05d75   475MB
docker-macsec                                      latest                          acb05bec6969   439MB
docker-macsec                                      master.244-3aec72879_Internal   acb05bec6969   439MB
docker-lldp                                        latest                          85f1ea2eb1a0   463MB
docker-lldp                                        master.244-3aec72879_Internal   85f1ea2eb1a0   463MB
docker-fpm-frr                                     latest                          ebb395f4d389   454MB
docker-fpm-frr                                     master.244-3aec72879_Internal   ebb395f4d389   454MB
docker-database                                    latest                          89d24c1c4f64   423MB
docker-database                                    master.244-3aec72879_Internal   89d24c1c4f64   423MB
urm.nvidia.com/sw-nbu-sws-sonic-docker/sonic-wjh   1.0.0-master-internal-18        2290464c0e59   468MB
harbor.mellanox.com/sonic/cpu-report               10.0.0                          5314b41a2a5e   413MB

[yxieca]

@alexrallen after system boots up, do these entries (e.g. /proc/sys/net/mpls/conf/Ethernet0/input) show up eventually or they are persistently missing?

[zhangyanzhao]

@TACappleman would you please help to take a look ? Thanks.

[TACappleman]

This will happen if the "mpls_router" module isn't loaded. This will only cause a problem if you actually wish to enable MPLS on a router - otherwise it will just attempt to set that MPLS is disabled, which will cause this log but no other effect.

I don't know whether the mpls_router module should be loaded by default so that this doesn't cause a log, and so that if MPLS is actually needed the command to enable it will work

[TACappleman]

@prsunny this is code in sonic-swss (intfmgr) that gets called whenever INTERFACE config exists (even if MPLS is disabled), and will always cause this log if the mpls_router module isn't loaded. If someone actually wants to enable MPLS that will then fail.

Should the mpls_router module be loaded by default in SONiC, and if so where is that done?

[dgsudharsan]

@prsunny @TACappleman Any further progress on this issue?

[Yuval-Mellanox]

@prsunny @TACappleman Any further progress on this issue?