IBM Eserver xSeries 360 Type 8686, User Reference Manual

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Chapter 3. Configuring the server
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After you set up the priority filter in Priority Packet, you must start PROSet, click the
Advanced tab, and select
QoS Packet Tagging from the list.
Note: IEEE 802.1p tagging increases the size of the packets it tags. Some hubs and
switches will not recognize the larger packets and will drop them. Check the
hub or switch documentation to see if they support 802.1p. (You can configure
the switch to strip the tags from the packets and send it on to the next
destination as normal traffic.) If these devices do not support 802.1p or if you
are not sure, use High Priority Queue (HPQ) to prioritize network traffic.
The requirements for effectively using IEEE 802.1p tagging are:
• The other devices receiving and routing 802.1p tagged packets must support
802.1p.
• The adapters on these devices must support 802.1p. The Ethernet controller in
the server, all IBM Netfinity 10/100 Ethernet Security Adapters, and IBM 10/100
Ethernet Server Adapters support 802.1p.
• The adapter cannot be assigned to an adapter team.
• If you are setting up VLANs and packet tagging on the same adapter, you must
start PROSet, click the Advanced tab, and select
QoS Packet Tagging from the
list.
If the network infrastructure devices do not support IEEE 802.1p or you are not sure,
you can still define filters and send packets as high priority. While High Priority
Queue (HPQ) does not provide the precise priority levels of 802.1p tagging, it does
assign traffic as either high or low priority and sends high priority packets first.
Therefore, if there are multiple applications on a system sending packets, the packets
from the application with a filter are sent out first. HPQ does not change network
routing, nor does it add any information to the packets.
To assign HPQ, you can specify it using Priority Packet when you create or assign a
filter.
To effectively use HPQ, the adapter cannot be assigned to an adapter team.
Virtual LAN mode
A virtual LAN (VLAN) is a logical grouping of network devices put together as a LAN,
regardless of their physical grouping or collision domains. Using VLANs increases
network performance and improves network security.
VLANs offer you the ability to group users and devices together into logical
workgroups. This can simplify network administration when connecting clients to
servers that are dispersed geographically across the building, campus, or enterprise
network.
Typically, VLANs are configured at the switch and any computer can be a member of
one VLAN per installed network adapter. The Ethernet controller supersedes this by
communicating directly with the switch, enabling multiple VLANs on a single network
adapter (up to 64 VLANs).
To set up VLAN membership, the Ethernet controller must be attached to a switch that
has VLAN capability. You also need to use Windows 2000, Windows NT 4.0 or later,
or Novell NetWare 4.1x or later.
Notes:
1. Windows NT versions prior to 4.0 do not support VLANs.