Single homed bgp issue

[Cool47]

Hello,

I am looking to safely migrate the default route from edge router to secondary ISP2 with BGP setup. But couldn't be able to create bgp session.

bgp config on 4455-01:

router bgp 100
bgp log-neighbor-changes
router-id 192.168.1.50
neighbor 192.168.1.49 remote-as 300
address-family ipv4 unicast
neighbor 192.168.1.49 activate
neighbor 192.168.1.49 soft-reconfiguration inbound
exit-address-family

Once the bgp session established, planning to advertise the subnet from the edge router and remove ISP1

network 100.x.x.x mask 255.255.255.0

the issue here is route is always taking place to ISP1 and unable to create bgp session. 

Could you guide me please.

Thank you.

[MHM Cisco World]

first config route-map with weight (highest weight win) for ISP1
here the router will have two path 
ISP1 with highest 
ISP2 with lowest weight 

then after that you can shut down interface to ISP1 
the router will use path via ISP2

[Edson A. Hernandez]

Show us the BGP configuration on ISP2 for neighbor relationship

[Flavio Miranda]

Hi

 I dont follow you here "But couldn't be able to create bgp session."

 If you have the config:

router bgp 100
bgp log-neighbor-changes
router-id 192.168.1.50
neighbor 192.168.1.49 remote-as 300
address-family ipv4 unicast
neighbor 192.168.1.49 activate
neighbor 192.168.1.49 soft-reconfiguration inbound
exit-address-family

The peering should come up. If you run the command show ip bgp you dont see the neighbor 192.168.1.49 ? 

This is a Lab or real  network?  But either way, does the ISP2 has the config to form neighborship with 4451 ?

[Cool47]

Thank you all for the quick responses, I really appreciated.

Yes, this is tested in lab(working as expected regular router but no ISR4455) and same configuration applied in the production. But it was disaster, the router crashed, rebooted and lost all logs. Based on research I think ISP2 send all routes, but no data to validate it.

Please confirm is that above configuration is sufficient for this requirement or am I missing something here?

Thanks again !!.

[Edson A. Hernandez]

share ISP2 BGP configuration to check

shwo us the show bgp ipv4 unicast summary

[MHM Cisco World]

neighbor 192.168.1.49 soft-reconfiguration inbound <<- this issue, this make Router save all prefix. 
instead use 
route refresh 
https://community.cisco.com/t5/switching/soft-reset-and-route-refresh-in-bgp/td-p/2674389