<div dir="ltr">Doing some testing on FRR here, and hoping for some assistance. Hopefully this is the right place to go. If not, please let me know!<div><br></div><div>I've got 3 remote iBGP peers that are configured as standard iBGP peers. These two iBGP peers learn some routes locally and then re-advertise these prefixes over a full-mesh iBGP network to each other, with FRR being one of the four routers in the mesh. The other three iBGP peers are Cisco.</div><div><br></div><div>FRR has one eBGP peer, to replicate re-advertising these routes out to iBGP. In our other three iBGP peers, we leverage route-maps to increment the received MED value of the route, so that we can prefer locally received eBGP routes - all else being equal - as opposed to those learned from our iBGP speakers in other locations. We also do this so locally originated prefixes from our AS have a higher metric when going out to eBGP speakers so they don't inadvertently get preferenced when there's a better path for the route to take.</div><div><br></div><div>I am receiving the routes from our iBGP speakers fine, and see the incremented MED on receipt of the routes from the aforementioned speaker. When I configure a local (to FRR) iBGP speaker as a route-reflector-client within the same AS, these pre-incremented MED's are correctly advertised to the local iBGP speaker and work just fine.</div><div><br></div><div>When advertising these same prefixes to an eBGP speaker with a different AS, the metric's are not readvertised, and only a locally originated prefix maintains any sort of metric at all. </div><div><br></div><div>Route's received from one of our remote iBGP speakers:</div><div><br></div><div>routert# sh bgp ipv4 unicast neighbors 1.1.1.1 received-routes<br>BGP table version is 0, local router ID is 2.2.2.2, vrf id 0<br>Default local pref 100, local AS 1234<br>Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,<br> i internal, r RIB-failure, S Stale, R Removed<br>Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self<br>Origin codes: i - IGP, e - EGP, ? - incomplete<br><br> Network Next Hop Metric LocPrf Weight Path<br>*> <a href="http://0.0.0.0/0">0.0.0.0/0</a>
1.1.1.1 100 100 0 i<br>*> <a href="http://1.2.3.0/20">1.2.3.0/20</a> 1.1.1.1 100 100 0 i<br>*> <a href="http://2.3.4.0/21">2.3.4.0/21</a> 1.1.1.1 100 100 0 5678 i<br>*> <a href="http://3.4.5.0/24">3.4.5.0/24</a> 1.1.1.1 100 100 0 5678 i<br>*> <a href="http://5.6.7.0/22">5.6.7.0/22</a> 1.1.1.1 102 100 0 5678 i<br>*> <a href="http://7.8.9.0/24">7.8.9.0/24</a> 1.1.1.1 102 100 0 5678 i<br><br>Total number of prefixes 6<br></div><div><br></div><div>Route's being correctly re-advertised and maintaining metric on re-advertisement to our local iBGP speaker (route-reflector-client):</div><div><br></div><div>router# sh bgp ipv4 unicast neighbors 3.3.3.3 advertised-routes<br>BGP table version is 4560509, local router ID is 2.2.2.2, vrf id 0<br>Default local pref 100, local AS 1234<br>Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,<br> i internal, r RIB-failure, S Stale, R Removed<br>Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self<br>Origin codes: i - IGP, e - EGP, ? - incomplete<br><br> Network Next Hop Metric LocPrf Weight Path<br>*> <a href="http://1.2.3.0/20">1.2.3.0/20</a> 1.1.1.1 100 100 0 i<br>*> <a href="http://1.2.7.0/23">1.2.7.0/23</a> 2.2.2.2 0 100 32768 i<br>*> <a href="http://2.3.4.0/21">2.3.4.0/21</a> 1.1.1.1 100 100 0 5678i<br>*> <a href="http://3.4.5.0/24">3.4.5.0/24</a> 1.1.1.1 100 100 0 5678 i<br>*> <a href="http://5.6.7.0/22">5.6.7.0/22</a> 1.1.1.1 102 100 0 5678 i<br>*> <a href="http://7.8.9.0/24">7.8.9.0/24</a> 1.1.1.1 102 100 0 5678 i<br><br>Total number of prefixes 6<br></div><div><br></div><div>Route's not maintaining their metric on re-advertisement to our local (to FRR) eBGP speaker:</div><div><br></div><div>router# sh bgp ipv4 unicast neighbors 8.8.8.8 advertised-routes<br>BGP table version is 4562244, local router ID is 2.2.2.2, vrf id 0<br>Default local pref 100, local AS 1234<br>Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,<br> i internal, r RIB-failure, S Stale, R Removed<br>Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self<br>Origin codes: i - IGP, e - EGP, ? - incomplete<br><br> Network Next Hop Metric LocPrf Weight Path<br>*> <a href="http://1.2.3.0/20">1.2.3.0/20</a> 0.0.0.0 100 0 i<br>*> <a href="http://1.2.7.0/23">1.2.7.0/23</a> 0.0.0.0 0 32768 i<br>*> <a href="http://2.3.4.0/21">2.3.4.0/21</a> 0.0.0.0 100 0 5678i<br>*> <a href="http://3.4.5.0/24">3.4.5.0/24</a> 0.0.0.0 100 0 5678 i<br>*> <a href="http://5.6.7.0/22">5.6.7.0/22</a> 0.0.0.0 100 0 5678 i<br>*> <a href="http://7.8.9.0/24">7.8.9.0/24</a> 0.0.0.0 100 0 5678 i<br><br>Total number of prefixes 6<br></div><div><br></div><div>Am I doing something wrong here? Otherwise a pretty straight forward BGP setup with some basic route-maps in and out, nothing too crazy. Is this expected behavior in FRR?</div><div><br></div><div>Running latest available stable release, FRRouting 7.1RPKI.</div><div><br></div><div>Thanks for any help.</div></div>