ZyXEL Communications MSC1000G Series, User Manual

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Chapter 12 Statistics Screens
Management Switch Card User’s Guide
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The following table describes the labels in this screen.
12.4 MAC Table
The MAC table lists device MAC addresses that are dynamically learned by the system. The table
shows the following for each MAC address: the port upon which Ethernet frames were received
from the device, to which VLAN groups the device belongs (if any) and to which channel it is
connected (for devices connected to DSL ports).
The switch uses the MAC table to determine how to forward frames. See the following figure.
1
The switch examines a received frame and learns the port on which this source MAC address came.
2
The switch checks to see if the frame's destination MAC address matches a source MAC address
already learned in the MAC table.
• If the switch has already learned the port for this MAC address, then it forwards the frame to
that port.
• If the switch has not already learned the port for this MAC address, then the frame is flooded
to all ports. Too much port flooding leads to network congestion.
• If the switch has already learned the port for this MAC address, but the destination port is the
same as the port it came in on, then it filters the frame.
Table 193
DHCP Statistics
LABEL DESCRIPTION
Slot Select the number of a line card’s slot.
Port Select the number of a DSL port on the line card.
Load Click Load to retrieve the port’s IGMP filter profile setting and display it in the Profile drop-
down list box.
Flush Click Flush to remove all of the entries from the table below.
Discover This field displays the number of DHCP Discover packets on this port.
Offer This field displays the number of DHCP Offer packets on this port.
Request This field displays the number of DHCP Request packets on this port.
Ack This field displays the number of DHCP Acknowledge packets on this port.
Overflow This field displays the number of IP addressees not added to the DHCP snooping table when it
is full.
Flush Click Flush to remove all of the entries from the table below.
Snooping
Table
Overflow This field displays whether the DHCP snooping table is full or not.
Index This field displays the index number.
IP This field displays the IP address assigned to a client n this port.
VID This field displays the VLAN ID of the VLAN to which the client computer belongs.
MAC Address This field displays the MAC address of the client computer.