Description

When receiving acx_nh_tag_hw_install() logs, ACX might be affected by scaling. The effect is that next-hop cannot be added on PFE.

Symptoms

ACX1000/2000 is able to install up to 2000 next-hops for MPLS labels received from ldp/rsvp . In the control plane, the route is learned correctly, but has a “discard” next-hop in forwarding table.

lab@001> show route 20.4.185.0/24

inet.0: 2221 destinations, 2221 routes (2221 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

20.4.185.0/24 *[OSPF/10] 3d 23:51:56, metric 4
> to 20.1.1.1 via ge-0/1/0.0

inet.3: 2190 destinations, 2190 routes (2190 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

20.4.185.0/24 *[LDP/9] 3d 23:51:53, metric 1
> to 20.1.1.1 via ge-0/1/0.0, Push 313344

lab@001> show route forwarding-table family mpls label 313344
Routing table: default.mpls
MPLS:
Destination Type RtRef Next hop Type Index NhRef Netif
default perm 0 dscd 50 1

Routing table: __mpls-oam__.mpls
MPLS:
Destination Type RtRef Next hop Type Index NhRef Netif
default perm 0 dscd 531 1

Solution

Jun 8 23:20:12 jtac-acx1000-fa-1 feb0 ACX_NH::acx_nh_tag_hw_install(),1911:acx_nh_tag_hw_install: BCM L3 Egress create object failed for NH 3984 (-14:No resources for operation), BCM NH Params: PFE:0, Port:5, VLAN:3013, L3_INTF:14 Flags: 0x0, mpls_qos_map_id:0
Jun 8 23:20:12 jtac-acx1000-fa-1 feb0 ACX_NH::acx_nh_tag_hw_install(),1915:NH-TYPE:2, NH-PROTO:5
Jun 8 23:20:12 jtac-acx1000-fa-1 feb0 nh_ucast_install:726Failed to create platform state for nh (3984), Unknown error: -14
Jun 8 23:20:12 jtac-acx1000-fa-1 feb0 nh_ucast_add:199Failed to install in platform, Unknown error: -14 for NH (3984)
Jun 8 23:20:13 jtac-acx1000-fa-1 feb0 nh_add_helper:916Type specific Add failed Unknown error: -14 nh-id:3984
Jun 13 22:28:55 jtac-acx1000-fa-1 feb0 (acx_rt_tag_entry_install:MPLS route add failed) Reason : -14, No resources for operation
Jun 13 22:28:55 jtac-acx1000-fa-1 feb0 acx_bcm_mpls_tunnel_switch_add: tunnel switch add failed (-14:No resources for operation)

To alleviate this problem:

  • Reduce the number of routes/FEC advertised from upstream router.

  • Implement an import policy if ldp is used for label distribution.

Modification History

2024-08-22: Updated Data category