Alteon Application Switch Operating System Application Guide
VLANs
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ID:
RDWR-ALOS-V2900_AG1302
VLANs and the IP Interfaces
You can access Alteon for remote configuration, trap messages, and other management functions
only from stations on VLANs that include an IP interface to Alteon. For more information, see the IP
Interface Menu section in the Alteon Application Switch Operating System Command Reference.
Likewise, you can cut off access to management functions to any VLAN by excluding IP interfaces
from the VLAN membership.
Note:
Carefully consider how you create VLANs so that communication with Alteon remains
possible.
For example, if all IP interfaces are left on VLAN 1 (the default), and all ports are configured for
VLANs other than VLAN 1, then management features are effectively cut off. If an IP interface is
added to one of the other VLANs, the stations in that VLAN will all have access to management
features.
VLAN Topologies and Design Issues
By default, Alteon has a single VLAN configured on every port. This configuration groups all ports
into the same broadcast domain. The VLAN has an 802.1Q VLAN PVID of 1. VLAN tagging is turned
off, because by default only a single VLAN is configured per port.
Since VLANs are most commonly used to create individual broadcast domains and/or separate IP
subnets, host systems should be present on more than one VLAN simultaneously. Alteon and VLAN-
tagging server adapters support multiple VLANS on a per-port or per-interface basis, allowing very
flexible configurations.
You can configure multiple VLANs on a single VLAN-tagging server adapter, with each VLAN being
configured through a logical interface and logical IP address on the host system. Each VLAN
configured on the server adapter must also be configured on the port to which it is connected. If
multiple VLANs are configured on the port, tagging must be turned on.
Using this flexible multiple VLAN system, you can logically connect users and segments to a host
with a single VLAN-tagging adapter that supports many logical segments or subnets.
If a 802.1Q tagged frame is sent to a port that has VLAN-tagging disabled, then the frames are
dropped at the ingress port.