[very common; by analogy with proton/electron/neutron, but doubtless reinforced after 1980 by the similarity to Douglas Adams's ‘Vogons’; see the Bibliography in Appendix C and note that Arthur Dent actually mispronounces ‘Vogons’ as ‘Bogons’ at one point]
1. The elementary particle of bogosity (see quantum bogodynamics). For instance, “the Ethernet is emitting bogons again” means that it is broken or acting in an erratic or bogus fashion.
2. A query packet sent from a TCP/IP domain resolver to a root server, having the reply bit set instead of the query bit.
3. Any bogus or incorrectly formed packet sent on a network.
4. By synecdoche, used to refer to any bogus thing, as in “I'd like to go to lunch with you but I've got to go to the weekly staff bogon”.
5. A person who is bogus or who says bogus things. This was historically the original usage, but has been overtaken by its derivative senses 1--4. See also bogosity, bogus; compare psyton, fat electrons, magic smoke.
The bogon has become the type case for a whole bestiary of nonce particle names, including the ‘clutron’ or ‘cluon’ (indivisible particle of cluefulness, obviously the antiparticle of the bogon) and the futon (elementary particle of randomness, or sometimes of lameness). These are not so much live usages in themselves as examples of a live meta-usage: that is, it has become a standard joke or linguistic maneuver to “explain” otherwise mysterious circumstances by inventing nonce particle names. And these imply nonce particle theories, with all their dignity or lack thereof (we might note parenthetically that this is a generalization from “(bogus particle) theories” to “bogus (particle theories)”!). Perhaps such particles are the modern-day equivalents of trolls and wood-nymphs as standard starting-points around which to construct explanatory myths. Of course, playing on an existing word (as in the ‘futon’) yields additional flavor. Compare magic smoke.