Design Tip— To
ensure optimal convergence for voice traffic Cisco recommends that VLAN
number assignments be mapped such that the most loss-sensitive
applications such as voice are assigned the lowest VLAN numbers on each
physical interface, as shown in table:
VLAN Function
|
VLAN Interface
|
|---|---|
Wired_Voice_VLAN
|
7
|
Wireless_Voice_VLAN
|
57
|
Wired_Data_VLAN
|
107
|
Wireless_Multicast_VLAN
|
157
|
Not all VLANs trunked on a specific interface converge at the same time.
Cisco IOS throttles the notifications for VLAN loss to the routing
process (EIGRP/OSPF) at a rate of one every 100 msec. As an example, if
you configure six VLANs per access switch, upon failure of an uplink,
fiber traffic on the sixth VLAN converges 500 msec after the first.
