On Sun, Sep 7, 2025 at 5:26 AM Martin Tonusoo via NANOG <nanog@lists.nanog.org> wrote:
Hi.
Meta(AS 32934) recently sent a cease NOTIFICATION message to its neighbors on AMS-IX and Piter-IX which had a "<0b>maintenance" string on the RFC 9003 "Shutdown Communication" field. In other words, the "Shutdown Communication" field contained "0b 6d 61 69 6e 74 65 6e 61 6e 63 65". At least on Junos(tested with versions 21.4R3-S3.4, 23.2R2-S4.5 and 25.2R1.9), calling the "get-bgp-summary-information" or "get-bgp-neighbor-information" RPCs using NETCONF returns the string containing the control character and this in turn means that libraries parsing the XML fail as 0x0b(vertical tab) is not in the allowed character range of XML 1.0: https://www.w3.org/TR/xml/#charsets
The admin shutdown message has been removed due to this exact parsing issue (the BGP NOTIFICATION message is correctly formatted over the wire). If you use RPCs like `get-bgp-neighbor-information` for the last shutdown reason, the parsing error might linger for some time. Apologies for the trouble. Yang