Customer noticed BGP SRGB related log on PTX10K 20.4X16.1-EVO:
Oct 20 06:04:53 2023 xxx rpd[23807]: Malformed Attribute PREFIX_SID(40) flag 0x00 length 10.
Oct 20 06:05:03 2023 xxx rpd[23807]: Total incoming malformed attributes from 10.11.3.81 (External AS 64830) since last logging
Oct 20 06:05:03 2023 xxx rpd[23807]: Received 1 malformed attribute PREFIX_SID(40)
Oct 20 06:05:03 2023 xxx rpd[23807]: Total incoming malformed attributes from 10.11.3.87 (External AS 64830) since last logging
Oct 20 05:29:10 2023 xxx rpd[23807]: BGP_PREFIX_SID_ATTR_DISCARD: Discarding bgp prefix sid attribute as E-BGP peer 10.11.3.81 (External AS 64830) not configured to accept it.
Oct 20 05:29:10 2023 xxx rpd[23807]: BGP_PREFIX_SID_ATTR_DISCARD: Discarding bgp prefix sid attribute as E-BGP peer 10.11.3.87 (External AS 64830) not configured to accept it.
Oct 20 04:49:16 2023 xxx rpd[23807]: Received malformed update from 10.11.3.87 (External AS 64830)
Oct 20 04:49:16 2023 xxx rpd[23807]: Family inet-labeled-unicast, prefix 172.29.64.1/56 (label 10320)
Oct 20 04:49:16 2023 xxx rpd[23807]: Malformed Attribute PREFIX_SID(40) flag 0x00 length 10.
BGP SRGB log on 20.4X16.1-EVO
This is expected as there is no configured Segment routing.
The log is related to the new feature of SPRING BGP-LU Prefix SID.
The Prefix SID for BGP-LU is supporting from 20.4R1-EVO.
https://apps.juniper.net/feature-explorer/feature-info.html?fKey=10480&fn=Prefix+SID+for+BGP-LU
Segment Routing uses Multiprotocol Label Switching (MPLS) labels to create a path to guide a packet in a network. Using segment routing, an MPLS label range is reserved with MPLS Forwarding Infrastructure (MFI). This label range is called Segment Routing Global Block (SRGB).
A prefix SID assigned to a prefix is an extension of SRGB. To support segment routing, Border Gateway Protocol (BGP) requires the ability to advertise a segment identifier (SID) for a BGP prefix. A BGP-Prefix-SID is the segment identifier of the BGP prefix segment in an segment routing with BGP network.
When BGP nodes communicate with neighbor nodes in a network, the BGP Update, message sent to neighbor nodes, includes the Prefix-SID Label in Labeled Unicast NLRI and a prefix SID index in a new attribute called Prefix SID attribute.
Each BGP node assigns a local label to the neighbors and advertises the local label as adjacency SID through BGP--link state updates.
Check the BGP neighbour which is currently advertising the SID and check on that device what is the need to include the SID for this router.
And add config of BGP SRGB and accept-prefix-sid:
e.g.
set protocols bgp source-packet-routing srgb start-label <> index-range <>
set protocols bgp group <> accept-prefix-sid