nexus 7000 error message

[Jozef Staruch]

Hi all,

can sombody of you explain what those error messages means? i am getting those error messages

2013 Jul  8 14:38:36 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 7 swidx 19 (0x13) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 14:38:36 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 8 swidx 19 (0x13) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 14:57:25 n7k-p-ntr010 %L2MCAST-SLOT6-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 0 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 14:57:25 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 0 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 14:57:25 n7k-p-ntr010 %L2MCAST-SLOT6-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 8 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 14:57:25 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 7 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 14:57:25 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 8 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 15:29:37 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 7 swidx 17 (0x11) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 15:29:37 n7k-p-ntr010 %L2MCAST-SLOT6-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 8 swidx 17 (0x11) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 15:49:12 n7k-p-ntr010 %L2MCAST-SLOT6-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 8 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

2013 Jul  8 15:49:12 n7k-p-ntr010 %L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 7 swidx 18 (0x12) with err (mac table full). To avoid possible multicast traffic loss, disa

ble OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

Thank you

[Ivan Shirshin · Accepted solution]

Hi Josef,

%L2MCAST-SLOT3-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 7 swidx 19 (0x13) with err (mac table full). To avoid possible multicast traffic loss, disable OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

Such messages mean that the mac address entry was not installed into the MAC table due to a hash function that is used to optimize the MAC table  usage.As a consequence, the multicast traffic will be dropped when IGMP snooping is enabled. If you disable IGMP snopping, the traffic will be flooded.

You can check current resources on the card with this command:

    attach module 3

         show hardware internal forwarding l2 table utilization instance all

The max L2 entries(MAC address) per  ASIC/Instance in the F2 module is 16K, there are totally 12 ASIC/Instance per F2 module (each ASIC controls 4 ports, for example instance 0 controls port 1-4), so theoretically, one F2 module can support up to 16k*12=192k MAC addresses. However each ASIC will synchronize the mac address table per VLAN with other ASICs with the same VLAN.  For example if ports 1 and 15 both allow vlan 1000, they will both have the mac address table entries for vlan 1000.  Thus, if vlan 1000 has 16K mac address table entries, no more entries will be able to be programmed into those two ASICs. You may be hitting such issues.

Therefore, it is suggested to only allow those required VLANs in the trunk port.

Following is a link for the N7K verified scalability:

http://www.cisco.com/en/US/partner/docs/switches/datacenter/sw/verified_scalability/b_Cisco_Nexus_7000_Series_NX-OS_Verified_Scalability_Guide.html#concept_1A55D144F3504CC49B22DD500E766A4E

Kind Regards,
Ivan Shirshin

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[Jozef Staruch]

thank you for help with this

[Devavrat Oka]

I'm seeing a similar problem on our Nexus 7710s. How did you fix your issue with the mac tables?

2014 Oct 29 13:03:36 endr %L2MCAST-SLOT2-2-L2MCAST_MAC_FULL_LC: Failed to insert entry in MAC table for FE 11 swidx 1 (0x1) with err (mac table full). To avoid possible multicast traffic loss, disable OMF. Use the configuration CLI: "no ip igmp snooping optimise-multicast-flood"

Thank you.