What I did:
Added support when TSA is done on Line Card make sure it's completely
isolated from all e-BGP peer devices from this LC or remote LC
Why I did:
Currently when TSA is executed on LC routes are withdrawn from it's connected e-BGP peers only. e-BGP peers on remote LC can/will (via i-BGP) still have route pointing/attracting traffic towards this isolated LC.
How I did:
When TSA is applied on LC all the routes that are advertised via i-BGP are set with community tag of no-export so that when remote LC received these routes it does not send over to it's connected e-BGP peers.
Also once we receive the route with no-export over iBGP match on it and and set the local preference of that route to lower value (80) so that we remove that route from the forwarding database. Below scenario explains why we do this:
- LC1 advertise R1 to LC3
- LC2 advertise R1 to LC3
- On LC3 we have multi-path/ECMP over both LC1 and LC2
- On LC3 R1 received from LC1 is consider best route over R1 over received from LC2 and is send to LC3 e-BGP peers
- Now we do TSA on LC2
- LC3 will receive R1 from LC2 with community no-export and from LC1 same as earlier (no change)
- LC3 will still get traffic for R1 since it is still advertised to e-BGP peers (since R1 from LC1 is best route)
- LC3 will forward to both LC1 and LC2 (ecmp) and this causes issue as LC2 is in TSA mode and should not receive traffic
To fix above scenario we change the preference to lower value of R1 received from LC2 so that it is removed from Multi-path/ECMP group.
How I verfiy:
UT has been added to make sure Template generation is correct
Manual Verification of the functionality
sonic-mgmt test case will be updated accordingly.
Please note this PR is on top of this :#16714 which needs to be merged first.
Signed-off-by: Abhishek Dosi <abdosi@microsoft.com>
What I did:
In Chassis TSA mode Loopback0 Ip's of each LC's should be advertise through e-BGP peers of each remote LC's
How I did:
- Route-map policy to Advertise own/self Loopback IP to other internal iBGP peers with a community internal_community as define in constants.yml
- Route-map policy to match on above internal_community when route is received from internal iBGP peers and set a internal tag as define in constants.yml and also delete the internal_community so we don't send to any of e-BGP peers
- In TSA new route-map match on above internal tag and permit the route (Loopback0 IP's of remote LC's) and set the community to traffic_shift_community.
- In TSB delete the above new route-map.
How I verify:
Manual Verification
UT updated.
sonic-mgmt PR: sonic-net/sonic-mgmt#10239
Signed-off-by: Abhishek Dosi <abdosi@microsoft.com>
* Use 20 and 30 route-map entries instead of 2 and 3 for TSA
* Added support for dynamic "Allow list" default action.
Co-authored-by: Pavel Shirshov <pavel.contrib@gmail.com>
Fixed TSA bugs:
1. TSA didn't advertise Loopback ipv6 address
2. TSA and TSB changed BGP dynamic and BGP monitors sessions
**- How to verify it**
Build an image and run on your DUT.
```
admin@str-s6100-acs-1:~$ TSA
System Mode: Normal -> Maintenance
admin@str-s6100-acs-1:~$ vtysh -c 'show bgp ipv4 neighbors 10.0.0.1 advertised-routes'
BGP table version is 6, local router ID is 10.1.0.32, vrf id 0
Default local pref 100, local AS 64601
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
*> 10.1.0.32/32 0.0.0.0 0 32768 i
Total number of prefixes 1
admin@str-s6100-acs-1:~$ vtysh -c 'show bgp ipv6 neighbors fc00::a advertised-routes'
BGP table version is 6, local router ID is 10.1.0.32, vrf id 0
Default local pref 100, local AS 64601
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
*> fc00:1::/64 :: 0 32768 i
Total number of prefixes 1
admin@str-s6100-acs-1:~$ TSB
System Mode: Maintenance -> Normal
```
Co-authored-by: Pavel Shirshov <pavel.contrib@gmail.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
