Intel BLADE SERVER IXM5414E - Manuale (Pagina 59)

36 Intel® Blade Server Ethernet Switch Module IXM5414E: Installation and User’s Guide:A Guide for Technically
• The ports that can be assigned to the same trunk have certain other restrictions, as described in
this section.
• Each port can only be assigned to one trunk group, whether a static or dynamic group.
• The ports at both ends of a connection must be configured as trunk ports.
• All of the ports in a trunk have to be treated as a whole when moved from/to, added, or deleted
from a VLAN.
• The Spanning Tree Protocol (STP) will treat all the ports in a trunk as a whole.
• Enable the trunk before connecting any cable between the switches to avoid creating a data loop.
• Disconnect all trunk port cables or disable the trunk ports before removing a port trunk to avoid
creating a data loop.
Trunking can be set as a static or a dynamic port/group using the IEEE 802.3ad Link Aggregation
commands. When trunking is enabled, a blue border will be placed around the ports on the Web
device panel display.
Static LAGs
When you create a LAG, the member links will attempt to exchange LACPDUs with their partners.
If a link does not receive a LACPDU within 3 seconds, it will come up with default values. If a
LACPU is later received with different values, the link will drop out of the LAG. When all member
links have dropped out, the LAG will reconfigure itself with the new values from the received
LACPDUs.
It is important that when you configure LAGs, you should configure the LAGs and enable STP on
both partner devices before connecting the cables.
Distribution method
Link aggregation, or port trunking, enables several ports to be grouped together and to act as a single
link. This gives a bandwidth that is a multiple of a single-link bandwidth.
Port trunking is most commonly used to link a bandwidth intensive network device or devices, such
as a server, to the backbone of a network.
The switch module offers link aggregation on four external ports for up to two static trunk groups or
two LACP 802.3ad link aggregation groups. The trunked ports can be non-continuous (that is, have
non-sequential port numbers). All of the ports in the group must be members of the same VLAN. In
addition, the trunked ports must connect at the same speed in full-duplex mode.
Load balancing is automatically applied to the ports in the trunked group, and a link failure within
the group causes the network traffic to be directed to the remaining links in the group.
The STP will treat a port trunking group as a single link on the switch level. On the port level, the
STP will use the port parameters of the Master Port in the calculation of port cost and in determining
the state of the port trunking group. If two redundant port trunking groups are configured on the
switch module, STP will block one entire group in the same way STP will block a single port that
has a redundant link.
Dynamic Host Configuration Protocol (DHCP)
The Dynamic Host Configuration Protocol (DHCP) can reduce the administrative burden of
assigning and maintaining IP address information. DHCP provides reliable and simple TCP/IP