Symptom

cEdge not advertising better route to BGP neighbor when received from OMP and setting a better attribute based on omp tags. ++ cEdge has route from TLOC with tag of 100: cEdge_20_3_2#sh sdwan omp routes a.b.c.d/plen detail | inc tloc|tag tloc w.x.y.z, public-internet, ipsec ultimate-tloc not set tag 100 cEdge_20_3_2# This is then redistributed into BGP to neighbor and has a route-map out to set prepending: cEdge_20_3_2#sh run | sec router router bgp 65001 bgp log-neighbor-changes ! address-family ipv4 vrf 1 redistribute omp neighbor 192.168.200.1 remote-as 65002 neighbor 192.168.200.1 activate neighbor 192.168.200.1 route-map OMP_TAG out exit-address-family ++ Route-map for AS-path prepending: cEdge_20_3_2#sh run | sec route-map neighbor 192.168.200.1 route-map PREPEND out route-map PREPEND permit 10 match omp-tag 100 set as-path prepend 65001 65001 65001 <<<<< route-map PREPEND permit 20 match omp-tag 200 set as-path prepend 65001 <<<< asr1k#sh ip bgp <<<< neighbor device Network Next Hop Metric LocPrf Weight Path *> a.b.c.d/plen 192.168.200.2 1000 0 65001 65001 65001 65001 ? <<<<<<<<<<<<<< asr1k# ++ When second TLOC is brought up, it updates OMP table: cEdge_20_3_2#show sdwan omp routes a.b.c.d/plen detail | inc tloc|tag tloc w.x.y.z, public-internet, ipsec ultimate-tloc not set tag 100 tloc w.x.y.z, biz-internet, ipsec ultimate-tloc not set tag 200 <<<<<<<<< ++ However it doens't update the newly added route with better prepending out BGP and the neighbor still prefers tag 100 when tag 200 is the better route. The cEdge is not advertising the tag 200 prepending but the tag 100: asr1k#sh ip bgp Network Next Hop Metric LocPrf Weight Path *> a.b.c.d/plen 192.168.200.2 1000 0 65001 65001 65001 65001 ? asr1k# ++ On customer env, they can get away with it by doing a "clear ip route vrf " however on the lab omp has to be cleared "clear sdwan omp all" cEdge_20_3_2#clear sdwan omp all ++ Neighbor device: asr1k#sh ip bgp Network Next Hop Metric LocPrf Weight Path *> a.b.c.d/plen 192.168.200.2 1000 0 65001 65001 ? <<<<<<<<< asr1k#

Conditions

Both: 1) cEdge ASR1K running 17.03.02, redistributing OMP into BGP, BGP outbound route-map with match omp-tag and set as-path prepend attributes. 2) Only BGP peering(s) in ipv4 vrf address-family, no VPNv4 address-family peering

Workaround

On ASR1K cEdge: clear sdwan omp all or clear ip route vrf vrf# or clear bgp vrf vrf# soft out

Further Problem Description