3Com Switch 7754, Configuration Manual

Page: 687 / 940

Overview 687
To implement remote port mirroring, you need to define a special VLAN, called
remote-probe VLAN, on all the three types of switches. In this VLAN, no normal
data but only mirrored packets are transmitted. All mirrored packets will be
transferred to the specified port of the destination switch from the source switch
through this VLAN. Thus, the destination switch can monitor the packets sent
from the ports of the remote source switch. remote-probe VLAN requires that:
■
It is recommended that you configure all relay ports in the remote-probe VLAN
to be trunk ports.
■
The default VLAN and management VLAN cannot be configured as
remote-probe VLAN.
■
Required configurations are performed to ensure Layer 2 connectivity between
the source and destination switches over the remote-probe VLAN.
c
CAUTION: To ensure the normal packet mirroring, you are not recommended to
perform any of the following operations on the remote-probe VLAN
■
Configuring a source port to the remote-probe VLAN that is used by the local
mirroring group;
■
Configuring a Layer 3 interface for the remote-probe VLAN;
■
Carrying other protocol packets or service packets;
■
Using remote-probe VLAN as a special type of VLAN, such as voice VLAN or
protocol VLAN;
■
Configuring other VLAN-related functions.
Local Traffic Mirroring Traffic mirroring maps traffic flows that match specific ACLs to the specified local
port for packet analysis and monitoring. Before configuring traffic mirroring, you
need to define ACLs required for flow identification.
Remote Traffic Mirroring Remote traffic mirroring copies traffic flows that match specific ACLs to the
reflector port of the specified mirroring group. Then, after corresponding
configurations of remote port mirroring, the matching traffic flows are finally
copied to the specified ports of other switches. Similar to configuring local traffic
mirroring, you need to define ACLs required for flow identification first.
Otherwise, you need to complete all configurations of remote port mirroring
(except the configuration of source port for mirroring).
Mirroring to Local I/O
Module
Mirroring to local I/O Module (including LS81VSNP and LS82VSNP) means copying
the packets received or sent on the specified port on the specified I/O Module to
the specified local I/O Module.
Destination switch Relay port Receive remote mirrored packets.
You must set the port as a trunk port and
specify the port to permit packets of
remote-probe VLANs.
Destination port Monitor remote mirrored packets
Table 552 Ports involved in the mirroring operation
Switch Ports involved Function