Bug 1983862

Description of problem:
ipv6_prefix doesn't update even configuration on server changed

Version-Release number of selected component (if applicable):
[root@dell-per740-12 bz1826623]# rpm -qa | grep -E "ovn-2021|openvswitch2.13"
python3-openvswitch2.13-2.13.0-117.el8fdp.x86_64
ovn-2021-21.06.0-12.el8fdp.x86_64
openvswitch2.13-2.13.0-117.el8fdp.x86_64
ovn-2021-central-21.06.0-12.el8fdp.x86_64
ovn-2021-host-21.06.0-12.el8fdp.x86_64

How reproducible:
Always

Steps to Reproduce:
systemctl start openvswitch                                                                                                                                                                        [33/1841]
systemctl start ovn-northd                                    
ovn-nbctl set-connection ptcp:6641   
ovn-sbctl set-connection ptcp:6642                   
ovs-vsctl set open . external_ids:system-id=hv1 external_ids:ovn-remote=tcp:20.0.39.25:6642 external_ids:ovn-encap-type=geneve external_ids:ovn-encap-ip=20.0.39.25
systemctl restart ovn-controller                         
ovn-nbctl ls-add ls1    
                                          
ovn-nbctl lr-add lr1                                                  
ovn-nbctl lrp-add lr1 lr1-ls1 00:00:00:00:00:01 172.16.1.1/24
ovn-nbctl lsp-add ls1 ls1-lr1                                            
ovn-nbctl lsp-set-type ls1-lr1 router                            
ovn-nbctl lsp-set-options ls1-lr1 router-port=lr1-ls1  
ovn-nbctl lsp-set-addresses ls1-lr1 router                         
                                     
ovn-nbctl lsp-add ls1 lnls1
ovn-nbctl lsp-set-options lnls1 network_name=provider
ovn-nbctl lsp-set-type lnls1 localnet       
ovn-nbctl lsp-set-addresses lnls1 unknown     
                                                                        
ovn-nbctl set logical_router lr1 options:chassis=hv1          
                                                                      
ovn-nbctl lrp-add lr1 lr1-ls2 00:00:00:00:00:02 172.16.1.2/24 
ovn-nbctl lrp-add lr1 lr1-ls3 00:00:00:00:00:03 172.16.1.3/24
ovn-nbctl ls-add ls2    
ovn-nbctl lsp-add ls2 ls2-lr1                              
ovn-nbctl lsp-set-type ls2-lr1 router
ovn-nbctl lsp-set-options ls2-lr1 router-port=lr1-ls2
ovn-nbctl lsp-set-addresses ls2-lr1 router                              
                                                             
ovn-nbctl ls-add ls3                                                  
ovn-nbctl lsp-add ls3 ls3-lr1                                 
ovn-nbctl lsp-set-type ls3-lr1 router
ovn-nbctl lsp-set-options ls3-lr1 router-port=lr1-ls3
ovn-nbctl lsp-set-addresses ls3-lr1 router

ovs-vsctl add-br br-test
ip link set br-test up
ovs-vsctl set open . external-ids:ovn-bridge-mappings=provider:br-test

ip netns add server0
ip link add veth0_s0 netns server0 type veth peer name veth0_s0_p
ip netns exec server0 ip link set veth0_s0 up
ip netns exec server0 ip addr add 2001:1db8:3333::2/64 dev veth0_s0
ovs-vsctl add-port br-test veth0_s0_p
ip link set veth0_s0_p up

ip addr add 2001:1db8:3333::1/64 dev br-test

ovn-nbctl set logical_router_port lr1-ls1 options:prefix_delegation=true
#ovn-nbctl set logical_router_port lr1-ls1 options:prefix=true
ovn-nbctl set logical_router_port lr1-ls2 options:prefix=true
#ovn-nbctl set logical_router_port lr1-ls3 options:prefix=true

cat > dhcpd6.conf << EOF
option dhcp-rebinding-time 15;
option dhcp-renewal-time 10;
option dhcp6.unicast fe80::f455:8ff:fe20:6d66;
subnet6 2001:1db8:3333::/64 {

        # Some /64 prefixes available for Prefix Delegation (RFC 3633)
        prefix6 2001:1db8:3333:100:: 2001:1db8:3333:111:: /80;
}
EOF

ip netns exec server0 dhcpd -6 -cf ./dhcpd6.conf veth0_s0
sleep 2
ovn-nbctl list logical_router_port lr1-ls2
ip netns exec server0 pkill dhcpd

ovn-nbctl set logical_router_port lr1-ls1 options:prefix_delegation=false
ovn-nbctl set logical_router_port lr1-ls2 options:prefix=false
ovn-nbctl clear logical_router_port lr1-ls2 ipv6_prefix
ovn-nbctl list logical_router_port lr1-ls2
sleep 5m
cat > dhcpd6-2.conf << EOF
option dhcp-rebinding-time 15;
option dhcp-renewal-time 10;
option dhcp6.unicast fe80::f455:8ff:fe20:6d66;
subnet6 2001:1db8:3333::/64 {

        # Some /64 prefixes available for Prefix Delegation (RFC 3633)
        prefix6 2001:1db8:3333:200:: 2001:1db8:3333:211:: /80;
}
EOF
ip netns exec server0 dhcpd -6 -cf ./dhcpd6-2.conf veth0_s0
sleep 2

ovn-nbctl set logical_router_port lr1-ls1 options:prefix_delegation=true
ovn-nbctl set logical_router_port lr1-ls2 options:prefix=true
sleep 2
ovn-nbctl list logical_router_port lr1-ls2

Actual results:
ipv6_prefix for ls1-lr2 doesn't update when dhcpd.conf changed

Expected results:
ipv6_prefix update to the new configuration

Additional info:


+ ovn-nbctl list logical_router_port lr1-ls2
_uuid               : f01adddc-7cca-4814-a2ae-befe7e903c9e              
enabled             : []                                      
external_ids        : {}                                     
gateway_chassis     : []                                                     
ha_chassis_group    : []                                     
ipv6_prefix         : ["2001:1db8:3333:111::/80"]        
ipv6_ra_configs     : {}                                                        
mac                 : "00:00:00:00:00:02"                                                             
name                : lr1-ls2                        
networks            : ["172.16.1.2/24"]    
options             : {prefix="true"}       
peer                : []                                              
+ ip netns exec server0 pkill dhcpd                           
+ ovn-nbctl set logical_router_port lr1-ls1 options:prefix_delegation=false
+ ovn-nbctl set logical_router_port lr1-ls2 options:prefix=false
+ ovn-nbctl clear logical_router_port lr1-ls2 ipv6_prefix                                                                                                          
+ ovn-nbctl list logical_router_port lr1-ls2             
_uuid               : f01adddc-7cca-4814-a2ae-befe7e903c9e                
enabled             : []                                       
external_ids        : {}                                              
gateway_chassis     : []                                     
ha_chassis_group    : []                                                 
ipv6_prefix         : []                                         
ipv6_ra_configs     : {}                               
mac                 : "00:00:00:00:00:02"                          
name                : lr1-ls2        
networks            : ["172.16.1.2/24"]          
options             : {prefix="false"}               
peer                : []                    
+ sleep 5m                                    
+ cat                                                                   
+ ip netns exec server0 dhcpd -6 -cf ./dhcpd6-2.conf veth0_s0 
Internet Systems Consortium DHCP Server 4.3.6                         
Copyright 2004-2017 Internet Systems Consortium.                             
All rights reserved.                                         
For info, please visit https://www.isc.org/software/dhcp/
ldap_gssapi_principal is not set,GSSAPI Authentication for LDAP will not be used
Not searching LDAP since ldap-server, ldap-port and ldap-base-dn were not specified in the config file
Config file: ./dhcpd6-2.conf                         
Database file: /var/lib/dhcpd/dhcpd6.leases                             
PID file: /var/run/dhcpd6.pid                                
No pool found for prefix 2001:1db8:3333:111::/80                      
Wrote 0 NA, 0 TA, 0 PD leases to lease file.                  
Bound to *:547                       
Listening on Socket/5/veth0_s0/2001:1db8:3333::/64
Sending on   Socket/5/veth0_s0/2001:1db8:3333::/64
+ sleep 2
+ ovn-nbctl set logical_router_port lr1-ls1 options:prefix_delegation=true
+ ovn-nbctl set logical_router_port lr1-ls2 options:prefix=true
+ sleep 2
+ ovn-nbctl list logical_router_port lr1-ls2                 
_uuid               : f01adddc-7cca-4814-a2ae-befe7e903c9e               
enabled             : []                                         
external_ids        : {}                               
gateway_chassis     : []                                           
ha_chassis_group    : []             
ipv6_prefix         : ["2001:1db8:3333:111::/80"]

<=== ipv6_prefix is still the old value.
<=== should update to "prefix6 2001:1db8:3333:200:: 2001:1db8:3333:211:: /80"

ipv6_ra_configs     : {}                             
mac                 : "00:00:00:00:00:02"   
name                : lr1-ls2                 
networks            : ["172.16.1.2/24"]                                 
options             : {prefix="true"}                         
peer                : []