Troubleshooting SFP transceivers and Packet captures
In an older blog post I was writing about Useful Cisco Commands for Troubleshooting cable problems. In this blog post I’m showing an additional, useful command for Fiber Optics troubleshooting and packet capturing on Cisco switches.
Stefan Thierolfhttps://creativecommons.org/licenses/by-nc-sa/4.0/https://thierolf.org/pages/impressum-imprint/Show idprom interface
The command show idprom interface is showing the IDPROM (Identification Programmable Read-Only Memory) information of the installed SPF/SPF+ transceivers. I find this command useful to figure out the SFP/SFP+ Transceiver I am dealing with and if the SFP/SFP+ Transceiver was detected by a Cisco switch properly. Note: HEX output is truncated.
#show idprom interface Gi2/0/26
General SFP Information
-----------------------------------------------
Identifier : 0x03
Connector : 0x07
Transceiver : 0x00 0x00 0x00 0x01 0x00 0x00 0x00 0x00
Encoding : 0x01
BR_Nominal : 0x0D
Vendor Name : CISCO
Vendor Part Number : FTLF8519P3BNL-CS
Vendor Revision : 0x41 0x20 0x20 0x20
Vendor Serial Number : nnnnnnnnnnn
-----------------------------------------------
EEPROM PAGE A0 bytes
-----------------------------------------------
000: HEXHEXHEX
-----------------------------------------------
EEPROM PAGE A2 Bytes
-----------------------------------------------
000: HEXHEXHEX
-----------------------------------------------
Other Information
-------------------------------------------------------
Port asic num : 04
Port asic port num : 02
SFP presence index : 01
SFP iter cnt : 83033469
SFP failed oper flag : 0x00000000
IIC error cnt : 0
IIC error dsb cnt : 0
IIC max sts cnt : 4
Chk for link status : 01
Link status : 01
Autoneg enable : 00
Flow control Pause : 00
Flow control asymPause: 00
Duplex mode : 00
PcsInfo : 0x060D4E60
MacInfo : 0x060D4E40 0x060D4E48
AutoNeg : 0x060D4E48 0x060D4E50
Sfp selection asic reg map
--------------------------------
stbi : 0x02
sfpControl : 0x5C
Regs Loc : 0xF0000000
--------------------------------
miscStatus
rps300Stat1 0
rps300Stat2 0
rps300Present 0
modeSwitchActive 0
stackPhyControl
sPhyLoopback 0
sPhyALock1 1
sPhyALock0 1
sPhyBLock1 1
sPhyBLock0 1
stackCable
cableIdA_1 0
cableIdA_0 0
eqSelectA_1 0
eqSelectA_0 0
cableIdB_1 0
cableIdB_0 0
eqSelectB_1 1
eqSelectB_0 1
SFF-8472 MSA EEPROM Data
===========================================
000 : HEXHEXHEX
SFF-8472 Digital Diagnostic Monitoring Data
===========================================
000 : HEXHEXHEX
YETI INTERNAL REGS
-----------------------------------------------
Location=0xD8000500 : Value=0x00
Location=0xD8000501 : Value=0x00
Location=0xD8000502 : Value=0x00
Location=0xD8000503 : Value=0x00
Location=0xD8000504 : Value=0x00
Location=0xD8000505 : Value=0x00
Location=0xD8000506 : Value=0x00
Location=0xD8000507 : Value=0x02
Location=0xD8000508 : Value=0x00
Location=0xD8000509 : Value=0x40
Location=0xD800050A : Value=0x00
Location=0xD800050B : Value=0x00
Location=0xD800050C : Value=0x05
Location=0xD800050D : Value=0x00
Location=0xD800050E : Value=0x01
Location=0xD800050F : Value=0x00
Location=0xD8000510 : Value=0x0F
yetiIICinited : Value=0x00000001
yetiIICLockPassCnt : Value=0
yetiIICLockFailCnt : Value=0
yetiIICLockApp : Value=40
-----------------------------------------------
Packet Capture
The famous packet capture commands on Cisco IOS is the monitor session command to activate the Switched Port Analyzer (SPAN). On my Cisco 3750 Switch series I would start a packet capture like in the example shown below and connect a laptop with Wireshark.
#conf t
(config)#monitor session 1 source interface Gi2/0/2
(config)#monitor session 1 destination interface Gi2/0/10
On the Cisco 9200 and 9300 Switch series (IOSXE) the packet capture capability was expanded with monitor capture. To start a packet capture, an ACL (Access Control List) must be defined first. The capture session is then using the defined ACL. The packet capture in this example is running 30 minutes, after the capture I can transfer the packet capture file by SCP (Secure Copy) to my laptop for analysis with Wireshark.
#monitor capture PCAP access-list PCAP
#monitor capture PCAP limit duration 1800
#monitor capture PACP interface Tw1/0/14 both
#monitor capture PCAP buffer circular size 10
#monitor capture PCAP start
...running 30 minutes....
#monitor capture PACP export scp://user:pass@ip:/capure.pcap