configuration is very simple
scenario: SLX01 (VERSION 17r.2 ) ----------10G fiber with IP ON INTERFACE -----------SLX02 (VERSION 18r.2)
SLX01:
neighbor X.X.X.X remote-as NNNN
neighbor X.X.X.X next-hop-self
neighbor X.X.X.X. soft-reconfiguration inbound
neighbor X.X.X.X send-community both
SLX02:
neighbor Y.Y.Y.Y remote-as NNNN
neighbor Y.Y.Y.Y next-hop-self
neighbor Y.Y.Y.Y. soft-reconfiguration inbound
neighbor Y.Y.Y.Y send-community both
ON SLX02:
# show ip bgp neighbors Y.Y.Y.Y routes detail
Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST C:CONFED_EBGP D:DAMPED
E:EBGP H:HISTORY I:IBGP L:LOCAL M:MULTIPATH m:NOT-INSTALLED-MULTIPATH
S:SUPPRESSED F:FILTERED s:STALE x:BEST-EXTERNAL
1 Prefix: 1.0.0.0/24, Rx path-id:0x00000000, Tx path-id:0x00190001, rank:0x00000002, Status: I, Age: 14h7m37s
NEXT_HOP: Y.Y.Y.Y, Metric: 0, Learned from Peer: Y.Y.Y.Y (NNNN)
LOCAL_PREF: 651, MED: 0, ORIGIN: igp, Weight: 0, GROUP_BEST: 1
AS_PATH: 13335
COMMUNITIES: NNNN:50031
AGGREGATOR: 13335(3.3.3.3)
ON SLX01:
# show ip bgp neighbors X.X.X.X routes detail vrf xxxx
Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST C:CONFED_EBGP D:DAMPED
E:EBGP H:HISTORY I:IBGP L:LOCAL M:MULTIPATH m:NOT-INSTALLED-MULTIPATH
S:SUPPRESSED F:FILTERED s:STALE x:BEST-EXTERNAL
1 Prefix: 45.171.128.0/24, Rx path-id:0x00000000, Tx path-id:0x00660001, rank:0x00000001, Status: BI, Age: 14h12m56s
NEXT_HOP: X.X.X.X , Metric: 0, Learned from Peer: X.X.X.X (NNNN)
LOCAL_PREF: 760, MED: none, ORIGIN: igp, Weight: 0, GROUP_BEST: 1
AS_PATH: 26434, 43434
look, after upgrade on slx01 communities not exist. even though communities are being sent they don't appear
