Contributed by Peter N. M. Hansteen on from the know yer neighbor ethernetly dept.
dlg@) is circulating a patch on tech@ that introduces the daemon,
List: openbsd-tech Subject: LLDP daemon and display tool From: David Gwynne <david () gwynne ! id ! au> Date: 2025-04-24 3:49:53 this adds a small daemon and command line tool for receiving and displaying LLDP messages from neighbors connected to Ethernet interfaces. the daemon is called olldpd(8) to avoid colliding with the existing lldpd from ports. the command line tool is lldp(8). it uses the AF_FRAME sockets that were recently added rather than BPF. this means it retains fewer privileges while it's running because it doesn't have to open and configure BPF devices when new interfaces appear in the system. avoiding BPF means it has basically 0 impact on the kernel packet path because AF_FRAME is handled as a last resort for packets rather than up front for every packet on an interface.
-- followed by the code itself.it's good enough now that i can leave the daemon running, and it handles interfaces coming and going, and lldp neighbours coming and going. the command line utility defaults to a brief output, but can produce verbose output that handles most of the basic set of lldp information from the specification. now that i've done the easy bits (AF_FRAME and the packet reception) i think it's time to get it into the tree so people can help with the hard stuff (pretty printing strings in c). things that i'd like to get working in the future are: - parse organisationally specific TLVs from IEEE specs - allow configuration to disable lldp reception on specified interfaces - query the daemon for stats/counters things that i do not want to get working in the future: - support for any other protocols like cdp/edp/etc long term it should be reasonable to implement tx so openbsd can send lldp packets to neighbor devices. this is what the command line tool looks like: dlg@r5s ~$ lldp IFACE SYSTEM PORTID CHASSISID rge0 rb450gx4 ether3 dc:2c:6e:87:a0:7c dlg@r5s ~$ lldp -v Local interface: rge0, Source address: dc:2c:6e:87:a0:7e Chassis ID: dc:2c:6e:87:a0:7c Port ID: ether3 Time-To-Live: 2m1s System Name: rb450gx4 System Description: MikroTik RouterOS 7.17 (stable) 2025-01-16 08:19:28 RB450Gx4 Management Address: 192.0.2.8, port 3 Management Address: fe80::de2c:6eff:fe87:a07c, port 3 System Capabilities: Bridge: enabled, Router: enabled Port Description: bridge/ether3 --- dlg@r6415 ~$ lldp IFACE SYSTEM PORTID CHASSISID bnxt0 eait-42-dc3-a2-2 ethernet1/1/9:1 8c:04:ba:c9:4a:c0 mcx0 eait-42-dc3-a2-2 ethernet1/1/8:1 8c:04:ba:c9:4a:c0 bnxt1 eait-42-dc3-a2-1 ethernet1/1/9:1 8c:04:ba:cf:6b:c0 mcx1 eait-42-dc3-a2-1 ethernet1/1/8:1 8c:04:ba:cf:6b:c0 dlg@r6415 ~$ lldp -i mcx0 IFACE SYSTEM PORTID CHASSISID mcx0 eait-42-dc3-a2-2 ethernet1/1/8:1 8c:04:ba:c9:4a:c0 dlg@r6415 ~$ lldp -i mcx0 -v Local interface: mcx0, Source address: 8c:04:ba:c9:4a:c8 Chassis ID: 8c:04:ba:c9:4a:c0 Port ID: ethernet1/1/8:1 Time-To-Live: 2m Port Description: Po38:r6415 System Name: eait-42-dc3-a2-2 System Description: Dell SmartFabric OS10 Enterprise. Copyright (c) 1999-2023 by Dell Inc. All Rights Reserved. System Description: OS10 Enterprise. OS Version: 10.5.6.0. System Type: S5248F-ON System Capabilities: Repeater: enabled, Bridge: enabled, Router: enabled Management Address: 8c:04:ba:c9:4a:c0, ifIndex 0 00-80-C2 subtype 1: 0000 00-80-C2 subtype 7: 0300000026 00-12-0F subtype 1: 0100020047 00-12-0F subtype 4: 2400 F8-B1-56 subtype 21: 20 F8-B1-56 subtype 22: 20 F8-B1-56 subtype 23: 20 F8-B1-56 subtype 24: 20 ---
Discussions are ongoing, and the code is in an early form as indicated. But if you are in a position to test and comment, you are invited to do so!