Download Accelar Network Concepts - Berkeley NOW

IP Interfaces and Router Management
1 Gbit
VLAN A
VLAN B
VLAN A
VLAN B
Switch operating
as a router
7811EA
Figure 4-2.
IP Routing Between VLANs
Virtual router interface addresses are also used for device management.
For SNMP or Telnet management, you can use any virtual router interface
address to access the routing switch as long as routing is enabled on the VLAN.
Brouter Ports
The Accelar switch also supports the concept of brouter ports. A brouter port is a
single-port VLAN that differs from an isolated routing port in that it can route IP
packets as well as bridge all nonroutable traffic. The difference between a brouter
port and a standard IP protocol-based VLAN configured to do routing is that the
routing interface of the brouter port is not subject to the spanning tree state of the
port. A brouter port can be in the blocking state for nonroutable traffic and still be
able to route the IP traffic. This feature removes any delays caused by spanning
tree in routed traffic.
To create a brouter port, configure a routed IP policy-based single-port VLAN into
spanning tree group 0. Subsequent VLANs on the port are part of the same
spanning tree group. When spanning tree blocks the port, the IP policy-based
VLAN will continue to forward (route) packets.
A brouter port is actually a one-port VLAN; therefore, each brouter port decreases
the number of available VLANs by one and uses one VLAN ID.
205588-A
4-5