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DGS-3600 Series Layer 3 Gigabit Ethernet Managed Switch CLI Manual
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DGS-3627:admin# show address_binding blocked
Command: show address_binding blocked
VID VLAN Name MAC Address Port
---- -------------------------------- ----------
1 default 00-01-02-03-29-38 7
1 default 00-0C-6E-5C-67-F4 7
1 default 00-0C-F8-20-90-01 7
1 default 00-0E-35-C7-FA-3F 7
1 default 00-0E-A6-8F-72-EA 7
1 default 00-0E-A6-C3-34-BE 7
1 default 00-11-2F-6D-F3-AC 7
1 default 00-50-8D-36-89-48 7
1 default 00-50-BA-00-05-9E 7
1 default 00-50-BA-10-D8-F6 7
1 default 00-50-BA-38-7D-E0 7
1 default 00-50-BA-51-31-62 7
1 default 00-50-BA-DA-01-58 7
1 default 00-A0-C9-01-01-23 7
1 default 00-E0-18-D4-63-1C 7
Total entries : 15
enable address_binding dhcp_snoop
Purpose Used to enable DHCP snooping mode.
Syntax
enable address_binding dhcp_snoop {[ipv6 | all]}
Description By default, DHCP snooping is disabled.
If a user enables DHCP sSnooping mode, all ports which have IMPB disabled will become
server ports. (The switch will learn the IP addresses through server ports (by using DHCP
Offer and DHCP ACK packets).
Note that the DHCP discover packet cannot be passed thru the user ports if the allow_zeroip
function is disabled on the port.
The auto-learned IMPB entry will be mapped to a specific source port based on the MAC
address learning function. This entry will be created as an ACL-mode binding entry for this
specific port. Each entry is associated with a lease time. When the lease time has expires,
the expired entry will be removed from the port. The auto-learned binding entry can be
moved from one port to another port if the DHCP snooping function has learned that the MAC
address has moved to a different port.
If a situation occurs where a binding entry learned by DHCP snooping conflicts with a
statically configured entry. The binding relation has conflicted. For example, if IP A is binded
to MAC X with a static configuration and suppose that the binding entry learned by DHCP
snooping is that IP A is bound to MAC Y, and then it is conflict. When the DHCP snooping
learned entry binds with the static configured entry, and the DHCP snooping learned entry
will not be created.
In a situation where the same IMPB pair has been statically configured, the auto-learned
entry will not be created. In a situation where the learned information is consistent with the
statically configured entry the auto-learned entry will not be created. In a situation where the
entry is statically configured in ARP mode the auto learned entry will not be created. In a
situation where the entry is statically configured on one port and the entry is auto-learned on
another port, the auto-learned entry will not be created.
Parameters
ipv6 - Enable DHCP snooping for IPv6.
all - Enable IPv4 and IPv6 DHCP snooping.
If no parameter is specified, IPv4 snooping is enabled.
