IP Configuration
IPv4 Management and Interfaces
273 Cisco Sx350, SG350X, SG350XG, Sx550X & SG550XG Series Managed Switches, Firmware Release 2.2.5.x
15
The following summarizes how DHCP packets are handled from both trusted and untrusted
ports. The DHCP Snooping Binding database is stored in non-volatile memory.
DHCP Snooping Packet Handling
Packet Type Arriving from Untrusted
Ingress Interface
Arriving from Trusted Ingress
Interface
DHCPDISCOVER Forward to trusted
interfaces only.
Forwarded to trusted interfaces only.
DHCPOFFER Filter. Forward the packet according to
DHCP information. If the destination
address is unknown the packet is
filtered.
DHCPREQUEST Forward to trusted
interfaces only.
Forward to trusted interfaces only.
DHCPACK Filter. Same as DHCPOFFER and an entry is
added to the DHCP Snooping Binding
database.
DHCPNAK Filter. Same as DHCPOFFER. Remove entry
if exists.
DHCPDECLINE Check if there is
information in the
database. If the
information exists and
does not match the
interface on which the
message was received,
the packet is filtered.
Otherwise the packet is
forwarded to trusted
interfaces only, and the
entry is removed from
database.
Forward to trusted interfaces only
DHCPRELEASE Same as
DHCPDECLINE.
Same as DHCPDECLINE.
DHCPINFORM Forward to trusted
interfaces only.
Forward to trusted interfaces only.
To Next Page
Loading...
Need help?
General
