Lantronix S3220 Series User Guide Rev J PDF 34.75 MB - Page 659

Transition Networks ION x222x / x32xx User Guide Layer 4 Switch A switch that makes forwarding decisions taking Layer 4 protocol information into account. LBM (Loopback Message) A unicast CFM PDU transmitted by a MEP, addressed to a specific MP, in the expectation of receiving an LBR. LBR (Loopback Reply) A unicast CFM PDU transmitted by an MP to a MEP, in response to an LBM received from that MEP. LED (Light Emitting Diode) An electronic light source. Link In IPv6, a communication facility or medium over which nodes can communicate at the link layer (i.e., the layer immediately below IPv6). Examples are Ethernets (simple or bridged); PPP links; X.25, Frame Relay, or ATM networks; and internet (or higher) layer "tunnels", such as tunnels over IPv4 or IPv6 itself. Link MTU The IPv6 Maximum Transmission Unit ‐ the maximum packet size in octets that can be conveyed over a link. Link-layer address n IPv6, a link‐layer identifier for an interface. Examples include IEEE 802 addresses for Ethernet links and E.164 addresses for ISDN links. Link-local address One of IPv6 addresses for local link usage. In IPv6, an address having link‐only scope that can be used to reach neighboring nodes attached to the same link. All interfaces have a link‐local unicast address. In IPv6, the two types of local‐use unicast addresses defined are Link‐Local and Site‐Local. The Link‐Local is for use on a single link and the Site‐Local is for use in a single site. Reference IETF RFC 2373. See also "Site‐Local unicast address". Link‐Local addresses are designed to be used for addressing on a single link for purposes such as automatic address configuration, neighbor discovery, or when no routers are present. Routers must not forward any packets with link‐local source or destination addresses to other links. All interfaces are required to have at least one link‐local unicast address. Site‐local addresses are designed to be used for addressing inside of a site without the need for a global prefix. Globally‐connected sites typically use the same subnet IDs for site‐local and global prefixes. Routers must not forward any packets with site‐local source or destination addresses outside of the site. 33472 Rev. J https://www.transition.com Page 659 of 700