BGP Step 2 - Add the announcement network Follow

Switch#1
sonic# configure terminal 
sonic(config)# router-id 3.3.3.3 
sonic(config)# router bgp 65101 
sonic(config-router)# neighbor 10.3.0.2 remote-as 65102
sonic(config-router)# address-family ipv4 
sonic(config-router-af)# network 192.168.1.0/24
sonic(config-router)# end

Switch#2
sonic# configure terminal 
sonic(config)# router-id 4.4.4.4 
sonic(config)# router bgp 65102 
sonic(config-router)# neighbor 10.3.0.3 remote-as 65101
sonic(config-router)# end

Switch#1

sonic# show ip bgp ipv4
BGP table version is 1, local router ID is 3.3.3.3, vrf id 0
Default local pref 100, local AS 65101
Status codes:  s suppressed, d damped, h history, * valid, > best, = multipath,
               i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes:  i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 192.168.1.0/24   0.0.0.0                  0         32768 i
Displayed  1 routes and 1 total paths

Switch#2

sonic# show ip bgp neighbors 10.3.0.3 routes
BGP table version is 1, local router ID is 4.4.4.4, vrf id 0
Default local pref 100, local AS 65102
Status codes:  s suppressed, d damped, h history, * valid, > best, = multipath,
               i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes:  i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 192.168.1.0/24   10.3.0.3                 0             0 65101 i

Displayed  1 routes and 1 total paths

sonic# write
Note: this version of vtysh never writes vtysh.conf
Building Configuration...
Integrated configuration saved to /etc/frr/frr.conf
[OK]