Specifications

344 ExtremeWare XOS 11.0 Concepts Guide
Glossary
Layer 2 Layer 2 is the second, or data link, layer of the OSI model, or the MAC
layer. This layer is responsible for transmitting frames across the
physical link by reading the hardware, or MAC, source and
destination addresses.
Layer 3 Layer 3 is the third layer of the OSI model. Also known as the
network layer, Layer 3 is responsible for routing packets to different
LANs by reading the network address.
LSA Link state advertisement. An LSA is a broadcast packet used by link
state protocols, such as OSPF. The LSA contains information about
neighbors and path costs and is used by the receiving router to
maintain a routing table.
LSDB Link state database. In OSPF, LSDB is a database of information about
the link state of the network. Two neighboring routers consider
themselves to be adjacent only if their LSDBs are synchronized. All
routing information is exchanged only between adjacent routers.
M
MAC address Media access control address. The MAC address, sometimes known as
the hardware address, is the unique physical address of each network
interface card on each device.
MAN Metropolitan area network. A MAN is a data network designed for a
town or city. MANs may be operated by one organization such as a
corporation with several offices in one city, or be shared resources
used by several organizations with several locations in the same city.
MANs are usually characterized by very high-speed connections.
master node In EAPS, the master node is a switch, or node, that is designated the
master in an EAPS domain ring. The master node blocks the
secondary port for all non-control traffic belonging to this EAPS
domain, thereby avoiding a loop in the ring.
master router In VRRP, the master router is the physical device (router) in the VRRP
virtual router that is responsible for forwarding packets sent to the
VRRP virtual router and for responding to ARP requests. The master
router sends out periodic advertisements that let backup routers on
the network know that it is alive. If the VRRP IP address owner is
identified, it always becomes the master router.
master VLAN In ESRP, the master VLAN is the VLAN on the ESRP domain that
exchanges ESRP-PDUs and data between a pair of ESRP-enabled
devices. You must configure one master VLAN for each ESRP domain,
and a master VLAN can belong to only one ESRP domain.
MED Multiple exit discriminator. BGP uses the MED metric to select a
particular border router in another AS when multiple border routers
exist.
L (continued)