vlan secondary interface exists in CONFIG_DB after removement of primary

[wen587]

Description

From linux side, the secondary interface IP will be removed if primary interface IP is deleted.
However, the secondary intf still existing CONFIG_DB

Steps to reproduce the issue

1. Check existing vlan interface

admin@vlab-01:~$ show run all | grep VLAN_INTER -A5
    "VLAN_INTERFACE": {
        "Vlan1000": {},
        "Vlan1000|192.168.0.1/21": {},
        "Vlan1000|fc02:1000::1/64": {}
    },
    "VLAN_MEMBER": {
admin@vlab-01:~$ ip addr show Vlan1000
894: Vlan1000@Bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9100 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:a9:e4:1a brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/21 brd 192.168.7.255 scope global Vlan1000
       valid_lft forever preferred_lft forever
    inet6 fc02:1000::1/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fea9:e41a/64 scope link

2. add secondary IP

admin@vlab-01:~$ sudo config interface ip add Vlan1000 192.168.0.2/21
admin@vlab-01:~$ show run all | grep VLAN_INTER -A5
    "VLAN_INTERFACE": {
        "Vlan1000": {},
        "Vlan1000|192.168.0.1/21": {},
        "Vlan1000|192.168.0.2/21": {},   <============
        "Vlan1000|fc02:1000::1/64": {}
    },
admin@vlab-01:~$ ip addr show Vlan1000
894: Vlan1000@Bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9100 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:a9:e4:1a brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.1/21 brd 192.168.7.255 scope global Vlan1000
       valid_lft forever preferred_lft forever
    inet 192.168.0.2/21 brd 192.168.7.255 scope global secondary Vlan1000   <===============
       valid_lft forever preferred_lft forever
    inet6 fc02:1000::1/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fea9:e41a/64 scope link
       valid_lft forever preferred_lft forever

3. remove primary ip and check CONFIG_DB

admin@vlab-01:~$ sudo config interface ip remove Vlan1000 192.168.0.1/21
admin@vlab-01:~$ ip addr show Vlan1000
894: Vlan1000@Bridge: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9100 qdisc noqueue state UP group default qlen 1000
    link/ether 52:54:00:a9:e4:1a brd ff:ff:ff:ff:ff:ff
    inet6 fc02:1000::1/64 scope global           <============ no secondary ip after primary removement
       valid_lft forever preferred_lft forever
    inet6 fe80::5054:ff:fea9:e41a/64 scope link
       valid_lft forever preferred_lft forever
       valid_lft forever preferred_lft forever
admin@vlab-01:~$ show run all | grep VLAN_INTER -A5
    "VLAN_INTERFACE": {
        "Vlan1000": {},
        "Vlan1000|192.168.0.2/21": {},
        "Vlan1000|fc02:1000::1/64": {}
    },
    "VLAN_MEMBER": {
admin@vlab-01:~$ ping 192.168.0.2
PING 192.168.0.2 (192.168.0.2) 56(84) bytes of data.
^C
--- 192.168.0.2 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

Describe the results you received

ip addr is contradict with CONFIG_DB

Describe the results you expected

CONFIG_DB should be algned with ip addr

Additional information you deem important (e.g. issue happens only occasionally)

Output of show version

admin@vlab-01:~$ show ver

SONiC Software Version: SONiC.master.161252-1f2ee7b72
Distribution: Debian 11.5
Kernel: 5.10.0-12-2-amd64
Build commit: 1f2ee7b72
Build date: Sun Oct 16 18:29:57 UTC 2022
Built by: AzDevOps@sonic-build-workers-0028WV

Platform: x86_64-kvm_x86_64-r0
HwSKU: Force10-S6000
ASIC: vs
ASIC Count: 1
Serial Number: N/A
Model Number: N/A
Hardware Revision: N/A
Uptime: 01:16:43 up 76 days, 22:53,  1 user,  load average: 0.04, 0.07, 0.10
Date: Fri 03 Mar 2023 01:16:43

Docker images:
REPOSITORY                    TAG                       IMAGE ID       SIZE
docker-orchagent              latest                    2f9b988fbc5a   486MB
docker-orchagent              master.161252-1f2ee7b72   2f9b988fbc5a   486MB
docker-fpm-frr                latest                    06ba5903a238   497MB
docker-fpm-frr                master.161252-1f2ee7b72   06ba5903a238   497MB
docker-teamd                  latest                    f5fe61425852   467MB
docker-teamd                  master.161252-1f2ee7b72   f5fe61425852   467MB
docker-macsec                 latest                    a2759f06d184   469MB
docker-gbsyncd-vs             latest                    ed81ab3e2966   459MB
docker-gbsyncd-vs             master.161252-1f2ee7b72   ed81ab3e2966   459MB
docker-dhcp-relay             latest                    f78af0be8396   460MB
docker-snmp                   latest                    c995e97fa0e9   497MB
docker-snmp                   master.161252-1f2ee7b72   c995e97fa0e9   497MB
docker-eventd                 latest                    e671a740aad3   451MB
docker-eventd                 master.161252-1f2ee7b72   e671a740aad3   451MB
docker-router-advertiser      latest                    547966567879   451MB
docker-router-advertiser      master.161252-1f2ee7b72   547966567879   451MB
docker-platform-monitor       latest                    52b171385c2b   576MB
docker-platform-monitor       master.161252-1f2ee7b72   52b171385c2b   576MB
docker-mux                    latest                    c454d8ba9b92   500MB
docker-mux                    master.161252-1f2ee7b72   c454d8ba9b92   500MB
docker-lldp                   latest                    f89c6e7e4c97   493MB
docker-lldp                   master.161252-1f2ee7b72   f89c6e7e4c97   493MB
docker-database               latest                    c0aab1af0bf0   451MB
docker-database               master.161252-1f2ee7b72   c0aab1af0bf0   451MB
docker-sonic-telemetry        latest                    bcff7e14161c   745MB
docker-sonic-telemetry        master.161252-1f2ee7b72   bcff7e14161c   745MB
docker-nat                    latest                    b9d7a3dece48   438MB
docker-nat                    master.161252-1f2ee7b72   b9d7a3dece48   438MB
docker-sflow                  latest                    7a29ae2edb65   436MB
docker-sflow                  master.161252-1f2ee7b72   7a29ae2edb65   436MB
docker-syncd-vs               latest                    5e29ba2bb5b7   432MB
docker-syncd-vs               master.161252-1f2ee7b72   5e29ba2bb5b7   432MB
docker-sonic-mgmt-framework   latest                    05d7cb848faa   564MB
docker-sonic-mgmt-framework   master.161252-1f2ee7b72   05d7cb848faa   564MB

[donbharath21]

Hi,

We are able to recreate this issue by following the above steps.

Root cause for this issue:
Their is no logic to handle the ip's as primary/secondary in the source code.

Observation:
Created the vlan id and assigned ip's to that vlan. While removing the "scope global ip" from linux side "scope global secondary ip" also get removed from the linux. But in the "config_db.json" file secondary ip's still remains.

Logs:
Logs - Adding & Removing of Vlan ip.docx

Observation from the logs:
In the logs three modules from the swss#orchagent are getting hit while assigning the ip's to the vlan.
"path: /sonic-buildimage/src/sonic-swss/orchagent/intfsorch.cpp" this where the code gets hits.

From the intfsorch.cpp file gone through this three module.
swss#orchagent: :- addRouterIntfs
swss#orchagent: :- addIp2MeRoute
swss#orchagent: :- addDirectedBroadcast

Observations from the source code:
1.Router Interface Addition (addRouterIntfs):
The code is responsible for adding router interfaces to the networking system based on the provided parameters and port information.It checks if a router interface already exists for a given port before attempting to create a new one.SAI API functions are used to create router interfaces with specific attributes.It updates port information, logs events, and, in a specific switch type case ("voq"), synchronizes the interface to a database table.

2.IP2Me Route Addition (addIp2MeRoute):
This code is focused on adding an IP-to-me route to the system based on the provided virtual router ID and IP prefix.It constructs a route entry with specific attributes, such as the packet action and next hop (CPU port).The code logs events, increments counters based on the IP address family, and calls a function related to flow counter handling.

3.Directed Broadcast Addition (addDirectedBroadcast):
The purpose of this code is to add a directed broadcast entry for a specific IPv4 subnet.It checks for specific conditions related to the IPv4 subnet and returns early if those conditions are not met.The broadcast IP is calculated, a neighbor entry is initialized, and a SAI API function is used to create the neighbor entry with the broadcast MAC address.
Logging is performed, and error handling is implemented.

This issue happen every time (not in occasionally)

We have verified on Both Target & VS-image also. Both images are master branch, cloned from community and complied locally and verified.

Output of Show Verison:
Output of show version.txt

Output of VS-Show Verison:
Output of VS - show version.txt