Why does bmp not support MultiPathList?

[sephiroth81]

case *watchEventBestPath:
info := &table.PeerInfo{
Address: net.ParseIP("0.0.0.0").To4(),
AS: b.s.bgpConfig.Global.Config.As,
ID: net.ParseIP(b.s.bgpConfig.Global.Config.RouterId).To4(),
}
for _, p := range msg.PathList {
u := table.CreateUpdateMsgFromPaths([]*table.Path{p})[0]
if payload, err := u.Serialize(); err != nil {
return false
} else if err = write(bmpPeerRoute(bmp.BMP_PEER_TYPE_LOCAL_RIB, false, 0, true, info, p.GetTimestamp().Unix(), payload)); err != nil {
return false
}
}
This one only takes the data from the PathList, but doesn't care about the MultiPathList. So multipath only receives the bmp message of the first rib, can I ask why it is designed this way?

[sephiroth81]

Could you give me some advise, thank you. @fujita

[fujita]

multiple paths are converted into multiple BMP messages?

[sephiroth81]

Yes. The question is if only take the PathList's path, only the first path will have the bmp message, so the route information get from the bmp message won't be the same as the real one. But if open multiple paths also sends bmp messages, I'm not sure if it will carry different pathID. @fujita

[sephiroth81]

@fujita I try to convert multiple paths to BMP messages, then I do get a bmp message for each route changes. But the new question is updates from multiple paths will only send the full paths, couldn't know which path is withdraw. If I want to use BMP to track path changes, how can i do? please give me some advises, thank you.

[fujita]

I'm not sure what you want to do. When gobgpd receives a BGP update message including multiple paths, each path separately is stored in a routing table. gobgpd doesn't store which paths were received in one message.

[sephiroth81]

I mean gobgpd receive the same route prefix from different peers(but different next-hop) or add global rib with the same prefix but different identify and next-hop. In these cases, seems gobgpd send bmp RM message（global rib）only when first path added. So from bmp message, it just There is only one next-hop route, but in fact this is multiple next hops route.
@fujita

[sephiroth81]

@fujita Could you give some advises？ Or I have some misconceptions about the use of BMP?