Hi,
Not sure what is the use of that label or its significance.
It's certainly not exchanged as part of BGP updates between EVPN neighbors as not seen in packet capture.
However, looks like it's derived from the VNID, last 4 HEX omitting the last one, effectively 3 HEX.
vnid in decimal: 5010
vnid in HEX: 1392
Label value in HEX: 139
Label value in Dec: 313
This appears to be consistent across different VNIDs:
vnid in decimal: 5201/5202/5216/5232
vnid in HEX: 1451/1452/1460/1470
Label value in HEX: 145/145/146/147
Label value in Dec: 325/325/326/327
BGP Type 3 received:
> show route receive-protocol bgp 192.168.1.2 match-prefix 3* detail | match "3:|Label"
* 3:192.168.1.2:1::5201::192.168.1.2/248 IM (1 entry, 0 announced)
PMSI: Flags 0x0: Label 325: Type INGRESS-REPLICATION 192.168.1.2
* 3:192.168.1.2:1::5202::192.168.1.2/248 IM (1 entry, 0 announced)
PMSI: Flags 0x0: Label 325: Type INGRESS-REPLICATION 192.168.1.2
* 3:192.168.1.2:1::5216::192.168.1.2/248 IM (1 entry, 0 announced)
PMSI: Flags 0x0: Label 326: Type INGRESS-REPLICATION 192.168.1.2
* 3:192.168.1.2:1::5232::192.168.1.2/248 IM (1 entry, 0 announced)
PMSI: Flags 0x0: Label 327: Type INGRESS-REPLICATION 192.168.1.2
From packet capture, there is no exchange of this value (326 in this case for vnid 5216) in PMSI_TUNNEL_ATTRIBUTE:
Path Attribute - PMSI_TUNNEL_ATTRIBUTE
Flags: 0xc0, Optional, Transitive, Complete
Type Code: PMSI_TUNNEL_ATTRIBUTE (22)
Length: 9
Flags: 0
Tunnel Type: Ingress Replication (6)
VNI: 5216
Tunnel ID: tunnel end point -> 192.168.1.2
Tunnel type ingress replication IP end point: 192.168.1.2
Not sure if this is intentional or possibly a bug.
Cheers,
------------------------------
Ashvin
------------------------------
Original Message:
Sent: 05-15-2021 13:46
From: Unknown User
Subject: Question on EVPN Type 3 Route
Hi.
Here is an EVPN Type 3 route advertised by a VXLAN VTEP:
user@S1> show route advertising-protocol bgp 4.4.4.4 match-prefix 3* detail
bgp.evpn.0: 1 destinations, 1 routes (1 active, 0 holddown, 0 hidden)
* 3:1.1.1.1:1::5010::1.1.1.1/248 IM (1 entry, 1 announced)
BGP group overlay type Internal
Route Distinguisher: 1.1.1.1:1
Route Label: 5010
PMSI: Flags 0x0: Label 5010: Type INGRESS-REPLICATION 1.1.1.1
Nexthop: Self
Localpref: 100
AS path: [100] I
Communities: target:100:5010
encapsulation:vxlan(0x8)
PMSI: Flags 0x0:
Label 313
Type INGRESS-REPLICATION
1.1.1.1
What is the MPLS label 313 used for?
Many thanks,
Deepak
Juniper Business Use Only