Brocade BigIron RX Series Configuration Guide - Manual (Page 216)

138 BigIron RX Series Configuration Guide
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CAM partitioning for the BigIron RX
5
Re-distributing CAM allocations
Depending on the needs of you network, the CAM allocations may need to be re-distributed. There
are two steps to the command.
1. Change the allocation used between the rules + PBR/RL and the IPv6 multicast entries.
2. Change the allocation of the ACL rules and the PBR/RL entries.
The total amount of CAM entries available is 1024 for each packet processor. If you want to
configure 600 for ACLs, 168 for PBR and Rate Limiters, and 256 for IPv6 multicast forwarding
entries, enter commands such as the following.
BigIron RX(config)#cam-partition rw session 768
BigIron RX(config)#cam-partition rw session rule-partition 600
If you want to configure 2 ACL entries and 2 IPv6 entries and 1020 Rate Limiting entries, enter a
command such as the following.
BigIron RX(config)#cam-partition rw session 1022
BigIron RX(config)#cam-partition rw session rule-partition 2
Syntax: cam-partition rw session <count>
Syntax: cam-partition rw session rule-partition <count>
The "cam-partition rw session xx" command allocates xx entries of the 1024 entries to
ACLs+(RL/QoS/PBR) and 1024-xx to the IPv6 multicast entries.
The "cam-partition rw session rule-partition yy" command gives the yy of xx entries to ACLs and
xx-yy entries to RL/QoS/PBR entries.
NOTE
A reload is required after a CAM partition command is configured for the CAM partition to take
effect.
NOTE
The minimum difference between session size and rule-partition size must be 23.
Nexthop table
The nexthop table on BigIron RX line cards contains next hop entries that are used by the routing
table entries to route IP traffic. One or more routes can point to the same next hop. Entries for
directly connected hosts are also present in the nexthop table. The nexthop table has 4096 entries
per line card by default. This table is divided into four partitions. First partition contains next hop
entries for routes with one routing path. This included directly connected host entries. Second
partition contains next hop entries for routes with two or less equal cost paths. Allocation from this
partition is always done in blocks of two entries. Third partition contains next hop entries for routes
with four or less equal cost paths. Allocation from this partition is always done in blocks of four
entries. The fourth partition contains next hop entries for routes with eight or less equal cost paths.
Allocation from this partition is always done in blocks of eight entries. For a given route, the next
hop entry is allocated based on the path count and best-fit algorithm. For example, to create a next
hop entry for a route with three equal cost paths, the entries are allocated from the four-path
partition. Four entries will be allocated from four-path partition even if the route has three equal
cost paths. If the four-path partition is full, the entries are allocated from the next partition, which is
the eight-path partition.