Virtual Lans (Vlans); Vlan Example - IBM 8677 - BladeCenter Rack-mountable - Power Supply Planning And Installation Manual

v TFTP server software must be running for TFTP services to work.
v For the configuration file uploaded to a TFTP server to be saved correctly, you
v Before the switch can upload its history log file to the TFTP server, an empty

Virtual LANs (VLANs)

VLANs allow multiple blade servers to be part of a logical group and prevents other
servers that do not belong to a given group from gaining direct access to the group
resources and data. The BladeCenter Ethernet switches can append a 4-byte VLAN
tag to ingress frames on a per-port basis, and use the tag on certain frames to
permit or block access to those frames at other ports. VLAN traffic can be restricted
to a single BladeCenter unit or can extend across multiple BladeCenter units. When
VLANs are extended across multiple BladeCenter units, intermediate switches use
the VLAN tag to block frames from non-member destinations.
When defining VLANs that span a chassis, consider the following:
v Blade Server ports that are in the same VLAN must have the same VLAN ID
v Define the same VLAN ID on both Ethernet switches for Blade Servers that use
v Ethernet switch ports used to span multiple BladeCenter units must be
v The external ports and Link Aggregation Groups must be members of all VLANs
v The intermediate network device that interconnects the BladeCenter units must
The BladeCenter unit default VLAN ID is 1 and includes all blade servers in the
chassis. If multiple VLANs are required additional VLAN IDs must be configured.
Review the following example to understand how VLANs can be configured.

VLAN example

The example shown in Figure 42 on page 78 defines three VLANs within a single
BladeCenter unit and multiple VLANs extended to multiple BladeCenter units.
Table 13 shows the defined VLAN parameters that are set to support this
configuration. Egress packets for internal blade server ports must be Untagged.
must first save switch module configurations to NVRAM.
history log file must exist on the TFTP server.
both switches to connect to the same external network.
configured as Tagged, with a specific default VLAN ID for any untagged packets.
that span multiple BladeCenter units.
be configured to handle tagged VLAN packets for all applicable VLAN traffic that
should be passed through the device.
Table 13. Sample VLAN configuration definitions
Port Number VLAN Id
1 1
2 1
3 1
4 2
5 2
6 2
7 3
8 3
9 3
VLAN Name Tagged/Untagged
Egress Packets
Default U
Default U
Default U
VLAN 2 U
VLAN 2 U
VLAN 2 U
VLAN 3 U
VLAN 3 U
VLAN 3 U
Chapter 5. Configuration considerations
Membership
Egress/Forbid/None
E 1
E 1
E 1
E 2
E 2
E 2
E 3
E 3
E 3
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