Brocade BigIron RX Series Configuration Guide - Manual (Page 592)

514 BigIron RX Series Configuration Guide
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Configuring rate limiting policies
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• Certain features such as FDP, CDP, UDLD and LACP that make the port run in dual mode can
cause traffic to be rate limited to less than the expected requested rate. When the port is in
dual-mode, all incoming or outgoing packets are treated as tagged. An extra 4 bytes is added
to the length of the packet to account for the tag, thus causing the requested rate to be less
than the expected requested rate. Ports in dual mode are assumed to be tagged ports for rate
limiting purpose.
• The CAM can hold up to 1024 ACL, PBR, and Rate Limiting entries and this maximum is divided
as follows:
• ACL – 416 entries
• Rate Limiting – 416, entries shared with PBR
Also note:
• Port-based and VLAN-based rate limiting policies consume one CAM entry per policy.
• ACL-based rate limiting policies consume entries based on the number of statements in an
ACL.
• See the limits in Table 107 .
Configuring rate limiting policies
Configuring rate-limiting policies involves using the rate-limit command and specifying the
requested rate and maximum burst at the interface level of the CLI.
Software release 02.4.00 adds rate limiting to outbound ports.
Configuring a port-based rate limiting policy
Only one port-based rate limiting policy can be applied to an inbound port.
To configure a port-based rate limiting policy, enter commands such as the following.
BigIron RX(config)# interface ethernet 1/1
BigIron RX(config-if-e1000-1/1)# rate-limit out 500000000 750000000
Average rate is adjusted to 499639656 bits per second
The commands configure a rate limiting policy for outbound traffic on port 1/1. The policy requests
to limit the rate on all outbound traffic to 500 Mbps with a maximum burst size of 750 Mbps. The
device adjusts the requested rate to 499639656 bits per second.
TABLE 107 Maximum # of rate limiting policies and VLANs w/ byte accounting permitted per-PPCR
Module type PPCR number Port # Max # of rate limiting policies based on ACLs and
VLANs + number of VLANs w/ byte accounting
enabled
4 x 10G PPCR 1 1 126
PPCR 2 2 126
PPCR 3 3 126
PPCR 4 4 126
24 x 1G PPCR 1 1 - 12 115
PPCR 2 13 - 24 115