Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 113)

Brocade Virtual ADX Switch and Router Guide 99
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Overview
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The portnum operand is used to specify the interface in order to display its rate limit statistics from
the following counters:
• packets forwarded - the total packets permitted by rate limiting
• packets dropped - the total packets dropped by rate limiting as and when the traffic rate
exceeds configured rate limiting values
• bytes forward - the total bytes permitted by rate limiting
• bytes dropped - the total bytes dropped by rate limiting as and when the traffic exceeds
configured rate limiting values
Clearing rate limit statistics
To clear the overall or per-port rate limit statistics, use the command as shown in the example:
Virtual ADX# clear rate-limit counters ethernet 1
Syntax: clear rate-limit counters [ ethernet portnum]
The portnum operand is used to clear the specified port’s rate limit statistics.
VLAN rate limiting
The ingress traffic to a specific VLAN is subject to rate limiting. Packets which exceed the
configured traffic rate limit are dropped. You can configure the VLAN rate limit parameters. You can
specify the VLAN on which rate limiting is applied.
This functionality is in addition to the global and port-level rate limiting. With the addition of VLAN
rate limiting, you can configure port-level and VLAN rate limiting. In such a case, the packet passes
through various rate limiters in the following order:
1. Global rate limiting
2. Port-level rate limiting
3. VLAN rate limiting
As a prerequisite, traffic is filtered to check for control packets before being subject to rate limiting.
Control packets are excluded form rate limiting. As a result, even if the traffic rate exceeds the rate
limit values configured, control packets will not be dropped.
VLAN rate limiting applies rate limiting on all the ingress traffic directed to a specific VLAN. Ingress
traffic on all the member ports of the VLAN is subject to rate limiting as per the user configuration.
Ingress traffic on both untagged and tagged VLANs is subject to rate limiting.
VLAN rate limiting ensures greater granularity for rate limiting. Also, a VLAN can be associated with
a single VE only and can be used for VE rate limiting as well.
NOTE
Management port does not support VLAN configuration. Hence, VLAN rate limiting is not applicable
to traffic from the management port.
Configuring VLAN rate limiting
The following command is used to configure VLAN rate limiting, in VLAN configuration mode.