MTU profile reset troubleshooting - DNX (NCS57XX)

rishetty · ‎05-22-2025

Introduction

MTU profile reset troubleshooting - DNX - NCS57XX

This document is mostly focus on troubleshooting of MTU on interface & how to verify if it is correctly programmed

Steps to follow

Check the Bundle configuration

RP/0/RP0/CPU0:NCS57XX#sh run int Bundle-Ether102

interface Bundle-Ether102

mtu 9216

ipv4 address 172.29.182.201 255.255.255.254

load-interval 30

!

RP/0/RP0/CPU0:NCS57XX#ping 172.29.182.200 size 1600 >>>>>>>> Not pinging due to MTU profile got changed from 9216 (MTU Profile 2) to 1514 (MTU Profile 1)

Type escape sequence to abort.

Sending 5, 1600-byte ICMP Echos to 172.29.182.200, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

RP/0/RP0/CPU0:NCS57XX#sh inter be102

Bundle-Ether102 is up, line protocol is up

Interface state transitions: 29

Hardware is Aggregated Ethernet interface(s), address is a0bc.6fbf.88dd

Internet address is 172.29.182.201/31

MTU 9216 bytes, BW 100000000 Kbit (Max: 100000000 Kbit)

reliability 255/255, txload 0/255, rxload 0/255

Encapsulation ARPA,

Full-duplex, 100000Mb/s

loopback not set,

Last link flapped 00:39:04

ARP type ARPA, ARP timeout 04:00:00

No. of members in this bundle: 1

HundredGigE0/0/2/0/0 >>>> Bundle members

Validate the MTU on IM data base

RP/0/RP0/CPU0:NCS57XX#show im database interface be102

View: OWN - Owner, L3P - Local 3rd Party, G3P - Global 3rd Party, LDP - Local Data Plane

GDP - Global Data Plane, RED - Redundancy, UL - UL

Node 0/RP0/CPU0 (0x1000)

Interface Bundle-Ether102, ifh 0x2000819c (up, 9216)

Interface flags: 0x000000000002a5d7 (REPLICATED|DYN_REP|BUNDLE

|VIS|DATA|CONTROL)

Encapsulation: ether

Interface type: IFT_ETHERBUNDLE

Control parent: None

Data parent: None

Views: UL|GDP|G3P|L3P|OWN

Protocol Caps (state, mtu)

-------- -----------------

None link_jump (up, 9216)

None qos_out (up, 9216)

None qos_in (up, 9216)

None ether (up, 9216)

arp arp (up, 9202)

clns clns (up, 9202)

ipv4 ipv4 (up, 9202)

mpls mpls (up, 9202)

ipv6 ipv6_preswitch (up, 9202)

ipv6 ipv6 (up, 9202)

ether_sock ether_sock (up, 9202)

Validate the MTU programming in OFA for bundle member interface.

show ofa objects all location 0/0/cpu0

l1port element 57 (hdl:0x308cca9428):
base
|-- dpd_slf -   pending(cr/up/dl):0/0/0, sibling:0x3091f7c328, child:12, num_parents:1, visits:0
   color_mask:0, last_bwalk_id:0 num_bwalks_started:0
|-- flag - 0
|-- keylen - 4
|-- trans_id - 1138343781
|-- create_trans_id - 57907
|-- obj_handle - 0x308cca9428
|-- obj_rc - 0x0
|-- reason - 0
|-- table_operation - 8
|-- total_obj_size - 1168
|-- idempotent - 0
|-- inflight - 0
|-- table_prop - jid=346 mtime=(GMT)2024.Jul.29 08:16:22.832097
|-- (cont'd) - replayed=0times
`-- obj_rc - 0:Success
ofa_npu_mask_t npu_mask => 1
@DPA_intf_t intf => 0x000040c8
  dpa_intf_name_t intf_name => HundredGigE0_0_2_0_0
int speed => 100000000
int speed_max => (not set)
  int mtu => 9216
int frame_max => (not set)

Validate the number of MTU profiles box is programmed

RP/0/RP0/CPU0:NCS57XX#show controllers fia diagshell 0 "dbal table dump table=ETPP_TRAP_MTU_MAP" location 0/0/cpu0

Node ID: 0/0/CPU0

R/S/I: 0/0/0

=====================================================================

| Entries dump table ETPP_TRAP_MTU_MAP |

| Total Entries: 5 |

=====================================================================

| # | LAYER_TYPE_| MTU_ || MTU_ | TRAP_ | TRAP_FWD_| TRAP_SNP_|

| | COMPRESSED | PROFILE || VALUE | ACTION_ | STRENGTH | STRENGTH |

| | | || | PROFILE | | |

=====================================================================

| 0 | 2 | 1 || 9216 | 3 | 7 | 0 |

| 1 | 7 | 1 || 1514 | 3 | 7 | 0 | >>>>>>> MTU profile 1 is set to 1514 MTU

| 2 | 7 | 2 || 9216 | 3 | 7 | 0 |>>>>>>> MTU profile 2 is set to 9216 MTU

| 3 | 7 | 3 || 9220 | 3 | 7 | 0 |

| 4 | 7 | 4 || 9224 | 3 | 7 | 0 |

=====================================================================

Validate the PP Port of Bundle member interface

RP/0/RP0/CPU0:NCS57XX#show controllers npu voq int Hu0/0/2/0/0 instance all location 0/0/cpU0

Mon Mar 3 17:34:24.070 IST

-------------------------------------------------------------------

Node ID: 0/0/CPU0

Intf Intf NPU NPU PP Sys VOQ Flow VOQ Port

name handle # core Port Port base base port speed

(hex) type

----------------------------------------------------------------------

Hu0/0/2/0/0 40c8 0 0 25 25 2008 7136 local 100G

Validate the MTU profile for bundle member interface

RP/0/RP0/CPU0:NCS57XX#show controllers fia diagshell 0 "dump ETPPC_EDITING_PER_PORT_TABLE 25 " location 0/0/cpu0

Node ID: 0/0/CPU0

R/S/I: 0/0/0

ETPPC_EDITING_PER_PORT_TABLE.ETPPC0[25]: <VLAN_MEMBERSHIP_INTERFACE=0,TX_TAG_VID=0,TX_TAG_ENABLE=0,TTL_MODEL=0,SIT_VID=0,SIT_PROFILE=0,SIT_PCP_DEI=0,REMARK_PROFILE=0,MTU_PROFILE=1,ECC=0>

Validate MTU profile against below CLI output

RP/0/RP0/CPU0:NCS57XX#show controllers fia diagshell 0 "dbal table dump table=ETPP_TRAP_MTU_MAP" location 0/0/cpu0

Node ID: 0/0/CPU0

R/S/I: 0/0/0

=====================================================================

| Entries dump table ETPP_TRAP_MTU_MAP |

| Total Entries: 5 |

=====================================================================

| # | LAYER_TYPE_| MTU_ || MTU_ | TRAP_ | TRAP_FWD_| TRAP_SNP_|

| | COMPRESSED | PROFILE || VALUE | ACTION_ | STRENGTH | STRENGTH |

| | | || | PROFILE | | |

=====================================================================

| 0 | 2 | 1 || 9216 | 3 | 7 | 0 |

| 1 | 7 | 1 || 1514 | 3 | 7 | 0 | >>>>>>>> MTU profile 1 is programmed as 1514

| 2 | 7 | 2 || 9216 | 3 | 7 | 0 |

| 3 | 7 | 3 || 9220 | 3 | 7 | 0 |

| 4 | 7 | 4 || 9224 | 3 | 7 | 0 |

=====================================================================

Validate the feature & parameters of the bundle

Below shows ipv4, ipv6 , MPLS feature is enabled

RP/0/RP0/CPU0:NCS57XX#show ether-ea interface be102 location 0/0/cpu0

Interface : 0x2000819c

l2intf details :

l3intf details :

IFH : 0x2000819c >>>> interface handle to be verified with IM database

MAC : a0:bc:6f:bf:88:dd >>>> MAC address of Bundle

TTL : 0

MTU : 0

PP_PORT : 234881144

VRF : 0

NPU_MASK : 0x00000001

INTF_ID : 0x0000007d

IPv4 : 1

IPv6 : 1

MPLS : 1

RP/0/RP0/CPU0:NCS57XX#show ether-ea interface be102 location 0/0/cpu0 | i rif

Mon Mar 3 15:52:35.130 IST

pm_info_l->intf_info.rif : 0x7d >>>>> Bundle Interface

pm_info_l->intf_info.rif : 0x7b

pm_info_l->intf_info.rif : 0x7b >>>>> Bundle member Interface

pm_info_l->intf_info.rif : 0x7b

pm_info_l->intf_info.rif : 0x7d

pm_info_l->intf_info.rif : 0x7b

pm_info_l->intf_info.rif : 0x7d

ifinfo->rif : 0x7d

Validate if the bundle member is programmed under bundle interface 102

With the help of mac-address, we can validate if it properly mapped to bundle & bundle-member interfaces

RP/0/RP0/CPU0:NCS57XX#show controllers fia diagshell 0 "l3 intf get id=0x7d" location 0/0/cpu0

Node ID: 0/0/CPU0

R/S/I: 0/0/0

===============================================================

| Intf entry get |

===============================================================

| ID | VRF | VID | Source MAC | TTL | MTU |

===============================================================

| 125 | 0x0000 | 0x007d | A0:BC:6F:BF:88:DD | 0x0000 | 0x0000 |

RP/0/RP0/CPU0:NCS57XX#show controllers fia diagshell 0 "l3 intf get id=0x7b" location 0/0/cpu0

Node ID: 0/0/CPU0

R/S/I: 0/0/0

===============================================================

| Intf entry get |

===============================================================

| ID | VRF | VID | Source MAC | TTL | MTU |

===============================================================

| 123 | 0x0000 | 0x007b | A0:BC:6F:BF:88:A0 | 0x0000 | 0x0000 |

===============================================================

Validate the MTU programming for all interface

RP/0/RP0/CPU0:NCS57XX#show controllers npu voq-usage interface all instance all location 0/0/cpu0
Wed Mar 12 16:21:56.418 IST

-------------------------------------------------------------------
Node ID: 0/0/CPU0
Intf Intf NPU NPU PP Sys VOQ Flow VOQ Port
name handle # core Port Port base base port speed
(hex) type
----------------------------------------------------------------------
TF0/0/0/8 108 0 0 33 33 1136 6264 local 25G
TF0/0/0/9 110 0 0 34 34 1144 6272 local 25G
TF0/0/0/10 118 0 0 35 35 1672 6800 local 25G
<snip>
Hu0/0/2/0/0 40c8 0 0 25 25 2008 7136 local 100G
Hu0/0/1/0/0 4348 0 0 105 105 1992 7120 local 100G
Hu0/0/1/1/0 4388 0 0 113 113 2000 7128 local 100G

RP/0/RP0/CPU0:NCS57XX#show controllers fia diagshell 0 "d chg ETPPC_EDITING_PER_PORT_TABLE" location 0/0/cpu0
Wed Mar 12 16:22:17.529 IST

Node ID: 0/0/CPU0

R/S/I: 0/0/0
ETPPC_EDITING_PER_PORT_TABLE.ETPPC0[17]: <MTU_PROFILE=2,>
ETPPC_EDITING_PER_PORT_TABLE.ETPPC0[25]: <MTU_PROFILE=1,>
ETPPC_EDITING_PER_PORT_TABLE.ETPPC0[33]: <MTU_PROFILE=2,>
ETPPC_EDITING_PER_PORT_TABLE.ETPPC0[34]: <MTU_PROFILE=2,>
ETPPC_EDITING_PER_PORT_TABLE.ETPPC0[35]: <MTU_PROFILE=2,>

You have to check if MTU profile is getting changed when interface is made down or when it comes UP

Logs Collections

This below logs will help TAC to narrow down the issues

show controller fia diag 0 "d chg ETPPC_CFG_EM_ACCESS_CMD" loc 0/0/cpu0

show controller fia diag 0 "swstate algo_port_pp esem access_cmd dump" loc 0/0/cpu0

show controller fia diag 0 "dbal table dump table=ESEM_ACCESS_CMD_TABLE" loc 0/0/cpu0 s

show controllers fia diagshell 0 "swstate dnx_algo_port pp_alloc dump pp_alloc_idx_0=0 " location 0/0/cPU0

show controllers fia diagshell 0 " swstate algo_port_pp port_pp_tpid_profile_egress dump" location 0/0/cpu0

show controllers fia diagshell 0 " vis lag" location 0/0/CPU0

show controllers fia diagshell 0 " tm lag" location 0/0/CPU0

show controllers fia diagshell 0 " vis port" location 0/0/CPU0

show controller fia traces all location 0/0/cpu0 | file harddisk:/fia_trace_lc

show ofa trace location 0/0/cPU0 | | file harddisk:/ofa_trace_lc

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