Nortel Alteon OS 42C4911 Application Manual page 250

Alteon OS Application Guide
Layer 3 Port Mirroring
(MP Packets, Both Ports in the Same GEA)
MP packets are generated by the management processor, such as routing packets between
direct interfaces. In this scenario, the mirrored port and the monitoring port reside on the same
Gigabit Ethernet Aggregator (GEA) unit. To find out which GEA unit each port resides on, use
the /info/geaport command.
The monitoring port always shows a tagged packet with a VLAN ID (VID) of the ingress port.
Layer 3 Port Mirroring
(MP Packets, Mirrored Port and Monitoring Port in Different GEAs)
MP packets are generated by the management processor, such as a ping to the switch inter-
faces. In this scenario, the mirrored port and the monitoring port reside on different Gigabit
Ethernet Aggregator (GEA) units. To find out which GEA unit each port resides on, use
the /info/geaport command.
N – The switch doesn't monitor Layer 3 egress-routed packets from the MP when the mir-
OTE
ror port and the monitoring port are in different VLANs.
Same VLAN as Mirrored Port
Different VLAN from Mirrored Port
N – When the monitoring port belongs to a different VLAN, all mirrored packets have
OTE
an 802.1q tag field with the VID of the VLAN to which the mirrored port belongs. The VID
included in the tag field depends on which port is monitored.
For example, assume a packet traverses from port EXT1 (VLAN 1) to EXT2 (VLAN 2), and is
monitored on port EXT3. When you monitor EXT1, the packet's tag includes the VID of
VLAN 1. When you monitor EXT2, the packet's tag includes the VID of VLAN 2.
250 Appendix A: Troubleshooting
Both ports tagged: Tagged packet with VID of the VLAN to which the ports belong
Mirrored port tagged, Monitoring port untagged: Untagged packet
Mirrored port untagged, Monitoring port tagged: Tagged packet with VID of the
VLAN to which the ports belong
Both ports untagged: Untagged packet
Both ports tagged: Tagged packet with VID of the VLAN to which the ports belong
Mirrored port tagged, Monitoring port untagged: Tagged packet with VID of the
VLAN to which the ports belong
Mirrored port untagged, Monitoring port tagged: Tagged packet with VID of the
VLAN to which the ports belong
Both ports untagged: Tagged packet with VID of the VLAN to which the ports belong
42C4911, January 2007