ZyXEL Communications 1 - Manual (Page 105)

NetAtlas Enterprise 1.00 User’s Guide
Chapter 11 Switch Configuration 104
11.6 Link Aggregation
11.6.1 Introduction to Link Aggregation
Link aggregation (trunking) is the grouping of physical ports into one logical higher-capacity
link. You may want to trunk ports if for example, it is cheaper to use multiple lower-speed
links than to under-utilize a high-speed, but more costly, single-port link.
However, the more ports you aggregate then the fewer available ports you have. A link
aggregation group is one logical link containing multiple ports.
The first port must be physically connected when forming a trunk group.
11.6.2 Dynamic Link Aggregation
The switch adheres to the 802.3ad standard for static and dynamic (LACP) port trunking.
The switch supports the link aggregation IEEE802.3ad standard. This standard describes the
Link Aggregate Control Protocol (LACP), which is a protocol that dynamically creates and
manages trunk groups.
When you enable LACP link aggregation on a port, the port can automatically negotiate with
the ports at the remote end of a link to establish trunk groups. LACP also allows port
redundancy, that is, if an operational port fails, then one of the “standby” ports become
operational without user intervention
Please note that:
• You must connect all ports point-to-point to the same Ethernet switch and configure the
ports for LACP trunking.
• LACP only works on full-duplex links.
• All ports in the same trunk group must have the same media type, speed, duplex mode
and flow control settings.
Configure trunk groups or LACP before you connect the Ethernet switch to avoid causing
network topology loops.
Forward Delay This is the maximum time (in seconds) a device will wait before changing
states. This delay is required because every device must receive
information about topology changes before it starts to forward frames. In
addition, each port needs time to listen for conflicting information that
would make it return to a blocking state; otherwise, temporary data loops
might result. The allowed range is 4 to 30 seconds (15 is the default).
Apply Click Apply to save your changes back to the switch.
Table 33 Configuration: Switch Configuration: STP Conf. (continued)
LABEL DESCRIPTION