Juniper JUNOS OS 10.3 - SOFTWARE, Manual

Page: 2950 / 3946

DHCP Snooping Information:
MAC Address IP Address Lease Type VLAN Interface
----------------- ---------- ----- ---- ---- ---------
00:05:85:3A:82:77 192.0.2.17 600 dynamic employee—vlan ge-0/0/1.0
00:05:85:3A:82:79 192.0.2.18 653 dynamic employee—vlan ge-0/0/1.0
00:05:85:3A:82:80 192.0.2.19 720 dynamic employee—vlan ge-0/0/2.0
00:05:85:3A:82:81 192.0.2.20 932 dynamic employee—vlan ge-0/0/2.0
00:05:85:3A:82:83 192.0.2.21 1230 dynamic employee—vlan ge-0/0/2.0
00:05:85:27:32:88 192.0.2.22 3200 dynamic employee—vlan ge-0/0/2.0
Meaning When the interface on which the DHCP server connects to the switch has been set to
trusted, the output (see preceding sample) shows, for each MAC address, the assigned
IP address and lease time—that is, the time, in seconds, remaining before the lease
expires.
If the DHCP server had been configured as untrusted, no entries would be added to the
DHCP snooping database and nothing would be shown in the output of the
show dhcp
snooping binding
command.
Verifying That DAI Is Working Correctly on the Switch
Purpose Verify that DAI is working on the switch.
Action Send some ARP requests from network devices connected to the switch.
Display the DAI information:
user@switch>
show arp inspection statistics
ARP inspection statistics:
Interface Packets received ARP inspection pass ARP inspection failed
--------------- --------------- -------------------- ---------------------
ge-0/0/1.0 7 5 2
ge-0/0/2.0 10 10 0
ge-0/0/3.0 12 12 0
Meaning The sample output shows the number of ARP packets received and inspected per
interface, with a listing of how many packets passed and how many failed the inspection
on each interface. The switch compares the ARP requests and replies against the entries
in the DHCP snooping database. If a MAC address or IP address in the ARP packet does
not match a valid entry in the database, the packet is dropped.
Verifying That MAC Limiting and MAC Move Limiting Are Working Correctly on
the Switch
Purpose Verify that MAC limiting and MAC move limiting are working on the switch.
Action Suppose that two packets have been sent from hosts on
ge-0/0/1
and five packets from
hosts on
ge-0/0/2
, with both interfaces set to a MAC limit of
4
with the default action
drop
.
Display the MAC addresses learned:
user@switch> show ethernet-switching table
Copyright © 2010, Juniper Networks, Inc. 2854
Complete Software Guide for Junos
®
OS for EX Series Ethernet Switches, Release 10.3