[sonic-quagga] Function defect, do NOT cancel route while connect IP down

[batmancn]

Hi all,

I found in sonic-quagga, do NOT cancel route while connect IP down.

1. How to produce

• use 2 SONiC, construct BGP peer
• SONiC-A have a connect IP with vlanif like this

    "VLAN_INTERFACE": {
        "Vlan201|10.130.2.1/24": {},
        "Vlan202|10.130.1.1/24": {},
        "Vlan203|10.130.3.1/24": {}
    },

• Then SONiC-B's quagga could learn these route by BGP peer
• Then down Vlan200, the connect IP with Vlan200 is also down

ifconfig vlan200 down

• But SONiC-B do NOT cancel this route !!!

2. route cause:

• there are 2 root cause of this case
  • 1. vlanmgr do NOT detect the vlan member down of a vlanif
  • 2. vlanmgr (or something else) do NOT report vlanif down and do NOT delete the connect IP of vlanif in redis DB

3. How to fix

• I suggest add code in vlanmgrd to fix these 2 root cause

4. My question

• What about my design ?