Dhcp Snooping Table; Static Ip Address Additions To The Dhcp Snooping Database; Snooping Dhcp Packets That Have Invalid Ip Addresses; Figure 65: Switch Acting As Relay Agent Through Router To Dhcp Server - Juniper JUNOS OS 10.3 - SOFTWARE Manual

Complete Software Guide for Junos

DHCP Snooping Table

Static IP Address Additions to the DHCP Snooping Database

Snooping DHCP Packets That Have Invalid IP Addresses

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OS for EX Series Ethernet Switches, Release 10.3

Figure 65: Switch Acting as Relay Agent Through Router to DHCP Server

The software creates a DHCP snooping information table that displays the content of
the DHCP snooping database. The table shows current IP-MAC bindings, as well as lease
time, type of binding, names of associated VLANs, and associated interface. To view the
table, type show dhcp snooping binding
user@switch> show dhcp snooping binding
DHCP Snooping Information:
MAC address IP address
00:05:85:3A:82:77 192.0.2.17
00:05:85:3A:82:79 192.0.2.18
00:05:85:3A:82:80 192.0.2.19
You can add specific static IP addresses to the database as well as have the addresses
dynamically assigned through DHCP snooping. To add static IP addresses, you supply
the IP address, the MAC address of the device, the interface on which the device is
connected, and the VLAN with which the interface is associated. No lease time is assigned
to the entry. The statically configured entry never expires.
If you enable DHCP snooping on a VLAN and then devices on that VLAN send DHCP
packets that request invalid IP addresses, these invalid IP addresses will be stored in the
DHCP snooping database until they are deleted when their default timeout is reached.
To eliminate this unnecessary consumption of space in the DHCP snooping database,
at the operational mode prompt:
Lease (seconds) Type
600 dynamic
653 dynamic
720 dynamic
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