Hallo Randy, That's interesting. At exact the same moment this is what our Juniper routers reported; --- May 20 07:01:51 router rpd[34930]: %DAEMON-4: bgp_read_v4_update:13937: NOTIFICATION sent to a.b.c.d (Internal AS xxx): code 3 (Update Message Error) subcode 131 (invalid), Data: 00 00 00 00 00 00 May 20 07:01:51 router rpd[34930]: %DAEMON-3: Received malformed update from a.b.c.d (Internal AS xxx) May 20 07:01:51 router rpd[34930]: %DAEMON-3: Family inet-vpn-unicast, prefix a.b.c.d:32767:156.230.0.0/40 (label 114) May 20 07:01:51 router rpd[34930]: %DAEMON-3: Malformed Attribute PREFIX_SID(40) flag 0x80 length 28 error 131 (TLV length error). --- Appears to be another prefix? Unfortunately we don't have a BMP dump of this packet. * Niels ________________________________ Van: Randy Bush via NANOG <nanog@lists.nanog.org> Verzonden: woensdag 21 mei 2025 22:47 Aan: Simon Lockhart via NANOG <nanog@lists.nanog.org> CC: Randy Bush <randy@psg.com> Onderwerp: Re: BGP malformed update/attribute list just to aol, and other posts did not show full nlri May 20 07:01:51 r2.f00 16869308: RP/0/RSP0/CPU0:May 20 07:01:51.437 : bgp[1059]: %ROUTING-BGP-3-MALFORM_UPDATE : Malformed UPDATE message received from neighbor 123.45.67.89 (VRF: default) - message length 106 bytes, error flags 0x000c0000, action taken "DiscardAttr". Error details: "Error 0x00040000, Field "Attr-length", Attribute 40 (Flags 0xe0, Length 28), Data [e0281c]". NLRIs: [IPv4 Unicast] 45.198.25.0/24 randy _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/56PKKMWI...