Configuration Guide User guide

FastIron Configuration Guide 941
53-1002494-02
VLAN-based mirroring
• If the VLAN is egress monitored and ports belonging to the VLAN are also egress monitored,
the egress traffic is mirrored for each egress port, as well as the VLAN, resulting in several
duplicated mirrored packets. The count of duplicate packets is computed as (1 + Number of
egress mirrored ports in the VLAN) * Number of egress packets.
In addition to the previously mentioned rules, the behavior of VLAN-based mirroring is affected by
the tag type of the ports belonging to that VLAN, as shown in Table 162.
As illustrated in Table 162, regardless of the egress port tag type, if a VLAN is egress mirrored, the
mirrored traffic is always tagged. This functionality is built into the hardware and is the expected
behavior, as the tag acts as an identifier for monitored traffic on the mirror-port (in case the
mirror-port belongs to some other VLAN).
Configuring VLAN-based mirroring on FastIron X Series devices
Configure VLAN-based mirroring using the monitor ethernet command in VLAN configuration mode.
For example, to enable incoming mirroring on VLANs 10 and 20, to mirror port e 6/24, enter the
following commands.
Brocade(config)#mirror-port ethernet 6/24
Brocade(config)#vlan 10
Brocade(config-VLAN-10)#monitor ethernet 6/24 input
Brocade(config-VLAN-10)#exit
Brocade(config)#vlan 20
Brocade(config-VLAN-20)#monitor ethernet 6/24 input
Brocade(config-VLAN-20)#end
For example, to enable outgoing mirroring on VLANs 10 and 20, to mirror port e 6/24, enter the
following commands.
Brocade(config)#mirror-port ethernet 6/24
Brocade(config)#vlan 10
Brocade(config-VLAN-10)#monitor ethernet 6/24 output
Brocade(config-VLAN-10)#exit
Brocade(config)#vlan 20
Brocade(config-VLAN-20)#monitor ethernet 6/24 output
Brocade(config-VLAN-20)#end
For example, to enable bidirectional mirroring on VLANs 10 and 20, to mirror port e 6/24, enter the
following commands.
Brocade(config)#mirror-port ethernet 6/24
TABLE 162 VLAN-based mirroring behavior: Tagged versus untagged ports
Ingress tag type Egress tag type VLAN-based mirroring
direction
Mirrored traffic tag type
Untagged Untagged Ingress Untagged
Untagged Untagged Egress Tagged
Untagged Tagged Ingress Untagged
Untagged Tagged Egress Tagged
Tagged Untagged Ingress Tagged
Tagged Untagged Egress Tagged
Tagged Tagged Ingress Tagged
Tagged Tagged Egress Tagged