If you’re a network engineer or network administrator, you’ll appreciate the pain of learning some of these mind-boggling names and concepts. We have listed them in reverse order to save the best for last. I hope you enjoy it.
5. VTP – VLAN Trunking Protocol. I am almost convinced that someone named this protocol as a practical joke. You see, VTP doesn’t actually transmit anything at all. However, it works closely with the actual VLAN trunking protocol that we innovatively know as 802.1q. For the uninitiated, it’s a bit like someone naming a hose ‘water’ and the actual water inside the hose H2O.
4. Multicast routing. This is an incredibly powerful but confusing notion to understand. While normal networks have a known source and destination, multicast networks work in reverse, giving rise to mind-boggling concepts like RPF (Reverse Path Forward). These networks have senders who have no idea of the destination. In fact, no entity in the network has a complete list of destinations. The packets find their way hop by hop following the members of the group until they finally reach their destination. It’s hardly an intuitive notion but definitely genius in its conception.
3. MPLS Experimental Bits: These three bits in an MPLS header appear to have fallen victim to a bureaucratic process. The IETF (Internet Engineering Task Force) could not reach a consensus to define those three bits as the CoS (Class of Service) field even though CoS is the main function of this field. However, the reason it got to number 3 on the countdown isn’t because CoS wasn’t called. The unfortunate labeling of these bits as ‘Experimental’ has cemented this name into a confusing place in the basket. Why didn’t the IETF call those bits ‘Universal Bits’ or ‘General Use Bits’ if in fact their function could not be agreed upon? The term ‘Experimental’ is similar to calling an established aircraft a ‘test aircraft’. Despite being reliable, it does not inspire confidence.
2. HSRP – Hot Standby Router Protocol is used to provide redundant gateways for hosts. In most Cisco software, setting up this technology is counterintuitive. To configure HSRP, the keyword ‘standby’ is used. For example, to view the HSRP instances, the ‘show standby’ command is issued. The problem with that is that standbys are actually one of the states of HSRP. You have one active router and one standby router. So, conceptually, you need to type ‘show standby’ (aka: show hsrp) to see the active router. This is the equivalent of typing ‘show back’ to see the front.
1. The MPLS S bit: This one always makes me laugh. RFC 3032 defines the MPLS label stack encoding. There is a particular bit in this header that is set to ‘1’ if it is the last entry in the label stack. In other words, if it’s the last label, the bottom of the stack, then the bit is set to 1. Intuitively, this bit should have been called the ‘BS’ bit… Bottom of stack, right? But it wasn’t, it’s just called the ‘S’ bit. If you think about it, BS makes more sense. When the ‘Bottom of Stack’ is 1 (aka True), we know that it is the last entry. It doesn’t make sense to say that if ‘Stack’ is 1 (aka True), then it’s the last entry, mainly because all previous labels were also the stack. We needed to specifically say that it is the ‘bottom’ of the stack. Why is that funny? Well, I would have thought that, as professionals, we could stop writing the acronym ‘BS’, which also has some more conventional, well-known connotations. It seems prudish to sacrifice an accurate description for the sake of shyness.
