Link Layer Discovery Protocol and Cisco's CDP can be used for devices to announce their identity and capabilities to a neighboring device
LLDP (Link Layer Discovery Protocol) is a vendor-neutral protocol that allows network devices to announce their identity, capability and neighbors in a local network. It is typically used in an Ethernet and, together with an LLDP-capable switch eliminates the guessing-game "on which port is this machine connected", among other uses. While originally used in data centers only we see it being adopted for client machines too, and as such NoTouch supports LLDP (and, for that matter, some proprietary counterparts such as Cisco's CDP):
- NoTouch can run an LLDP service to announce itself to its LLDP-capable neighbors
- NoTouch will send announcements or neighbors to NoTouch Center (visible in the "Info" tab of a client)
The LLDP functionality is part of the "Network Management Plus" (NMP) upgrade package and license. It was added in NoTouch OS 2.40.4282.
LLDP configuration
You will find the relevant parameters in the Services->LLDP section. Simply switching it on will actually be sufficient for most use cases. It is really that simple!
- Enable LLDP service. The master switch to turn LLDP on or off.
- Disable kernel, system version advertising. Normally NoTouch will advertise it with version information which some users don't want (security principle - share only minimal information). Hence there is a switch to turn that off.
- Custom system description. This allows you to set a totally custom system description altogether. If you fill this out, the kernel-system-version-disabling switch above doesn't matter any more, because the description will be "custom" anyway. Supports Macro expansion.
- Emit LLDP-MED frames of specified class. LLDP-MED ("Media Endpoint Discovery") is an extension that allows for more detailed information and classification of your endpoint devices. The switch gives you a few options. Note: Without setting this option, no LLDP-MED frames will be generated.
CDP configuration
CDP (Cisco Discovery Protocol) is a proprietary protocol to be used with Cisco products. The LLDP software used on NoTouch speaks CDP as well.
- Enable CDP. This will enable CDP functionality. (You still need to have the LLDP master switch on for this to work!)
- Override CDP platform name. By default, the platform name on CDP will simply be "Linux". Here you can specify your custom description.
Customization
The bundled software LLDPD allows for much more detailed configuration. You can specify both command line options for lldpd as well as configuration file options. Whatever you specify here will be used verbatim, that means you need to familiarize with the lldpd software's documentation: LLDPD usage