"received-only" prefix in "show ip bgp" output

I configured "ip community-list" and "route-map" in router named "r2" in order to prepend AS path, modify origin attribute and decrease local-preference value based on the community value attached to received prefix. This "route-map" works fine, but why do I receive two prefixes and one of those is "received-only"?

Before the route-map was applied:

r2#sh ip bgp 192.168.1.0
BGP routing table entry for 192.168.1.0/24, version 13
Paths: (1 available, best #1, table default)
  Not advertised to any peer
  65000, (received & used)
    10.10.10.1 from 10.10.10.1 (192.168.1.1)
      Origin IGP, metric 0, localpref 100, valid, external, best
      Community: 1111:222
r2#

After the route-map was applied:

r2#sh ip bgp 192.168.1.0                  
BGP routing table entry for 192.168.1.0/24, version 14
Paths: (2 available, best #1, table default)
  Not advertised to any peer
  65000 65000 65000 65000 65000 65000 65000 65000 65000 65000 65000
    10.10.10.1 from 10.10.10.1 (192.168.1.1)
      Origin incomplete, metric 0, localpref 87, valid, external, best
      Community: 1111:222
  65000, (received-only)
    10.10.10.1 from 10.10.10.1 (192.168.1.1)
      Origin IGP, metric 0, localpref 100, valid, external
      Community: 1111:222
r2#

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Comments

srg

Are you using soft-inbound-reconfiguration? In that case the recevied-only route are how the prefix was sent to you, before your router applied all its policies.

m4rtin

srg wrote: »

Are you using soft-inbound-reconfiguration? In that case the recevied-only route are how the prefix was sent to you, before your router applied all its policies.

Yes, I'm using "soft-reconfiguration inbound". Thank you for explaining this! In addition, if I disable "soft-reconfiguration inbound", I save some memory:

"soft-reconfiguration inbound" enabled:

3 path entries using 168 bytes of memory

"soft-reconfiguration inbound" disabled:

2 path entries using 112 bytes of memory

srg

yes soft-reconfiguration inbound keeps a copy of the original prefix pre-filtering stored in memory so it might take up quite a lot of memory depending on the situation.