Allied Telesis x900-48 series - Manual (Page 14)

Page 14 | AlliedWare™ OS How To Note: DHCP snooping on AT-9900-style switches
DHCP filtering > Resource considerations
Resource considerations
Because of the potential for classifier replication, you need to be cautious about running out
of classifier resource. Some resource calculations are provided below.
When configuring DHCP classifiers you need to guard against running out of classifier
resource, especially when using a complex QoS classifier solution.
Calculations
The number of rules used = number of classifiers * number of ports attached
* dhcpsn max lease per port
The number of rules used = 2 * number of classifiers * number of ports attached
* dhcpsn max lease per port
As the above output shows, the command show switch gives a breakdown of the current
usage of rule resource.
X
To calculate the number of snooping classifiers:
X
To calculate the number of snooping classifiers when DHCP snooping ARP
security is also enabled:
X
To see the number of rules used, and still available:
Manager > show switch
Traffic Control Unit, hardware resource usage:
Total system rule space ....... 2048
Total number of rules used .... 403
Total rule space usage ........ 408
Number of rules per application:
MLD Snooping ................ 51
DHCP Snooping ............... 102
QOS ......................... 250
MLD snooping = multicast listen discovery for Ipv6