TCAM distribution on x670

[Vadim]

Hi,
Could you please explain, HW Route Table stored in the same memory (TCAM?) as HW L3 Hash table, or it's different storage? I.e, accordingly to output below, can be 16352 IPv4 routes with 4096 IPv4 MCast entries at the same tame?

# sh iproute reserved-entries statistics
|-----In HW Route Table----| |--In HW L3 Hash Table--|
# Used Routes # IPv4 Hosts IPv4 IPv4 IPv6 IPv4
Slot Type IPv4 IPv6 Local Remote Local Rem. Loc. MCast
---- ------ ------ ----- ------ ------ ----- ----- ---- -----
1 X670-48x 9746 0 362 0 0 0 0 1173

Theoretical maximum for each resource type:
X670 16352 8176 8189 16384 8189 8192 4096 *4096

[Vadim]

PIM configured on switch, and a lot of multicast flows passes through switch, so 1400 entries looks reasonable, and we can't change lookup key. 'debug hal show ipv4mc' shows also group-table info, I mean 70 entries in that table:
Total IPMC Cache Entries : 6 Total IPMC Caches with No Group Index : 0 IPMC Group Table Entries In-use : 68 IPMC Group Table Entries Max : 185The issue is that switch complains that L3 Table Full, but I don't saw even 2000 entries in L3 Hash Table. Guess software upgrade required to fix the issue.

Thank you for support!

[Sumit_Tokle]

The default behaviour of the switch you can verify with "show forwarding configuration" command output.

[Sumit_Tokle]

The ‘IPv4 MCast’ column is displaying the number of IP multicast layer-3 entries stored in the ‘L3 table’. Each of these entries represents a unique key. These entries can be displayed via ‘debug hal show ipv4mc’. If there is anticipated contention with other entries with in the ‘L3 table’ and the IP multicast forwarding is layer-2 only (no PIM, PVLAN, IGMPv3, or MVR) then you can consider using ‘config forwarding ipmc lookup-key mac-vlan’ to instead utilize the L2 MAC FDB table to handle IGMP snooping forwarding.”

[Vadim]

Dear Sumit,

Thank you for clarification!
The matter is that switch periodically complains on "IPv4 multicast entry not added. Hardware L3 Table full. (Logged at most once per hour.)". At that moment I see 10700 routes and 1400 multicast entries. Could you please advice how the issue could be solved?

There are zero "no room" counters in "debug hal show forwarding distributions system", and "debug hal show ipv4Mc gaddr x.x.x.x" shows only 70 table entries occupied from 185 available (table compression enabled). Output of "show igmp snooping cache" shows (as I can remember) 1380 entries from snooping, 0 MVR, 30 from PIM.

[Sumit_Tokle]

The "Route Table" (LPM) is a separate table from the "L3 Hash Table". The first line of that output attempts to group the columns into 2 different HW Tables (Route Table and L3 Hash Table).