BLADE OS™ Application Guide HP GbE2c Ethernet Blade Switch for c-Class BladeSystem Version 5.1 Advanced Functionality Software

BLADE OS 5.1 Application Guide
BMD00113, September 2009 Chapter 4: VLANs  93
As shown in Figure 10, the tagged packet remains unchanged as it leaves the switch through port 5,
which is configured as a tagged member of VLAN 2. However, the tagged packet is stripped
(untagged) as it leaves the switch through port 7, which is configured as an untagged member of
VLAN 2.
Figure 10 802.1Q Tagging (after 802.1Q tag assignment)
Note – Set the configuration to factory default (/boot/conf factory) to reset all
non-management ports to VLAN 1.
VLANs and IP interfaces
Carefully consider how you create VLANs within the switch, so that communication with the
switch remains possible. In order to access the switch for remote configuration, trap messages, and
other management functions, be sure that at least one IP interface on the switch has a VLAN
defined.
You can also inadvertently cut off access to management functions if you exclude the ports from the
VLAN membership. For example, if all IP interfaces are left on VLAN 1 (the default), and all ports
are configured for VLAN 2, then switch management features are effectively cut off.
To remedy this, keep all ports used for remote switch management on the default VLAN and assign
an IP interface to the default VLAN.
For more information on configuring IP interfaces, see the “Configuring an IP Interface” on
page 26.
Port 6 Port 7 Port 8
Port 1
Port 4 Port 5
Port 2 Port 3
802.1Q Switch
Key
Priority
CFI
VID
- User_priority
- Canonical format indicator
- VLAN identifier
PVID = 2
Tagged member
of VLAN 2
Untagged member
of VLAN 2
After
DA
SA
Data
CRC*
(*Recalculated)
Outgoing
untagged packet
changed
(tag removed)
DASADataCRC Tag
VID = 2Priority
16 bits 3 bits 1 bit 12 bits
8100 CFI