**- Why I did it**
FRR introduced [next hop tracking](http://docs.frrouting.org/projects/dev-guide/en/latest/next-hop-tracking.html) functionality.
That functionality requires resolving BGP neighbors before setting BGP connection (or explicit ebgp-multihop command). Sometimes (BGP MONITORS) our neighbors are not directly connected and sessions are IBGP. In this case current configuration prevents FRR to establish BGP connections. Reason would be "waiting for NHT". To fix that we need either add static routes for each not-directly connected ibgp neighbor, or enable command `ip nht resolve-via-default`
**- How I did it**
Put `ip nht resolve-via-default` into the config
**- How to verify it**
Build an image. Enable BGP_MONITOR entry and check that entry is Established or Connecting in FRR
Co-authored-by: Pavel Shirshov <pavel.contrib@gmail.com>
Signed-off-by: Abhishek Dosi <abdosi@microsoft.com>
The one big bgp configuration template was splitted into chunks.
Currently we have three types of bgp neighbor peers:
general bgp peers. They are represented by CONFIG_DB::BGP_NEIGHBOR table entries
dynamic bgp peers. They are represented by CONFIG_DB::BGP_PEER_RANGE table entries
monitors bgp peers. They are represented by CONFIG_DB::BGP_MONITORS table entries
This PR introduces three templates for each peer type:
bgp policies: represent policieas that will be applied to the bgp peer-group (ip prefix-lists, route-maps, etc)
bgp peer-group: represent bgp peer group which has common configuration for the bgp peer type and uses bgp routing policy from the previous item
bgp peer-group instance: represent bgp configuration, which will be used to instatiate a bgp peer-group for the bgp peer-type. Usually this one is simple, consist of the referral to the bgp peer-group, bgp peer description and bgp peer ip address.
This PR redefined constant.yml file. Now this file has a setting for to use or don't use bgp_neighbor metadata. This file has more parameters for now, which are not used. They will be used in the next iteration of bgpcfgd.
Currently all tests have been disabled. I'm going to create next PR with the tests right after this PR is merged.
I'm going to introduce better bgpcfgd in a short time. It will include support of dynamic changes for the templates.
FIX:: #4231
