Is the "show interface brief" command 100% safe?

I am planning on performing a health check on multiple Cisco SAN switches. This check will be performed five or more times a day. I know that the "show" commands are usually safe commands, but I have seen instances where "show tech-support" has caused the supervisor to restart. This type of outage is not acceptable.
1) Does anyone know of an instance where "show interface brief" has caused any kind of problem?
2) I currently use Device Manager to perform health checks. Does Device Manager use a "show interface" command to display port states?
3) What kind of CPU usage does "show interface brief" have on a SAN switch?
4) Does anyone have a low-level explanation of what happens when a "show interface brief" command is executed?
5) Is it safe to run "show interface brief" many times a day and every day of the year?

i can tell you that we run "show int fc X" every 5 minutes. We use a perl script that telnets to the switch every 5 minutes, runs "show int fc X" on specific ports, dumps output to log file on the server and then parses it for link status. This is how we monitor our DWDM links.

Similar Messages

Show ip interface brief command output

Hi,
I have seen 'show ip interface brief' command output.
For some interfaces 'method' it is showing 'NVRAM' and for some interfaces it is 'Manual'.
What does it mean?
Regards
SKR

hello,
what about CONFIG method. what is the difference between that and manual and how can I change it to CONFIG? this is related to the ASA 5585.
thanks!!

I used a terminal command to show the Library in the User folder, and now the Finder is behaving erractically. Can anyone tell me how to reverse the show library terminal command?

I used a terminal command in Lion to show the LIbrary in the Users folder, and now the Finder is behaving erratically, hanging up and becoming almost paralyzed. Can anyone tell me how to reverse the terminal command for show Library. The command I used was:
chflags nohidden ~/Library/

Showing the Library folder will not cause the problem you've described. Nevertheless:
chflags hidden ~/Library
will hide the folder. To reveal the folder:
chflags nohidden ~/Library
Note, there is no "/" after Library.

WAAS and the 'show connection statistics command'

HI Everyone
In need of some help in understanding how/where the numbers come from when looking at the how the reduction ratio is calculated.
In an example I can see the following:
                        Original            Optimized
Bytes Read:      390                   157385
Bytes Written:   246821               4251
Total Reduction Ratio: 34.616%
The definition for the reduction ratio in the command reference is "number of bytes that have been read and written on the original (incoming) side and the optimised (outgoing) side".
Taking that logic on the above numbers I see Endpoing ----> WAE reading in 390 bytes ----> WAE sending 4251 bytes optimised to another peer ----> then the WAE recieving the reply from its peer 157385 bytes ---> and sending it 246821 Bytes.
I can understand the last part where the optimised read is lower than the original write, due to the DRE/LZ that is going on but why would the optimised write be higher than the original read??
Likewise here is another example:
                        Original            Optimized
Bytes Read:      6GB              9MB
Bytes Written:    1MB             587MB
Total Reduction Ratio: 90.0
Now - I can see this command is run on a WAE where it is the "Server end" of the connection due the large read value on the Original (LAN) side.
BUT why is the optimised read greater than the original write???
I will be eternally grateful to anyone who can explain this to me ....
Regards

Hi Ryan,
Let me try to explain you.
1st Scenario
This output looks to be taken from the WAE closer to the client.
Original Bytes Read: This is the client request that is sent to the server to the get the data. This is intercepted by the WAE on the original side (LAN)
Optimized Bytes Read: This is the amount of data that the WAE has received from WAN against the original request.
Original Bytes Written: This is the amount of data that the WAE has sent towards the LAN to the client after decoding and replacing the encoded packets with actual data content.
The Reduction Ratio goes like this (Optimized Read + Optimized Write) / (Original Read + Original Write)
= (1 - (157385 + 4251) / (390 + 246821)) % = 34.616%
Scenario 2
The output is from the Server side WAE.
Original Bytes Read: This is the amount of data that the WAE received from the LAN side (which is server)
Optimized Bytes Written: This is the amount of data that the WAE has sent out on the WAN after performing the encoding process.
Original Bytes Written: This is the acknowldgements that the WAE has sent to the server on LAN.
Optimized Bytes Read: This is the amount the data received by the WAE from the other WAE acknolwdgements and other administrative exchange for this session.
So if we apply the above formula in this case:
= (1 - (9 + 587) / (6000 + 1)) % = 90.202%
Hope this helps.
Regards
Kiran

'show interface trunk' output

My question is..
interface Gi0/1 on access switch (Switch A) configured as trunk port allowing multiple vlans (say vlan 100-105)
Now, this interface Gi0/1 on switch A has no issues and configured fine.
Another switch B connected to Switch A and working fine. both sw A & sw B up and working fine
But, switch B is now say disconnected from Switch A which causes the interface Gi0/1 on SW A go down.
when I do a "show interface trunk" on Switch A, will the output show trunked vlans 100-105 or the output will not show the trunked vlans as the interface on Switch A is down because the Switch B is disconnected???
Basically, all I want to know is when an interface configured for trunking multiple vlans go down will the "show interface trunk" command list those vlans 100-105 in the output ???
Thanks for looking into my q

When the link is down, you will get a "blank" output to the command "sh interface trunk".

About the output of "show dot11 associations" command.

Hello.
I have been made to the research of IP Phone 9971 . (Used by Wireless)
The schematic diagram is shown below.
CUCM
      |
L3-SW
      |
AP 1142 (FW:15.2(2)JB)
      |
CP-9971 (FW:9.3(2))
The results of the "show dot11 associations" command are output as follows.
ap#show dot11 associations
802.11 Client Stations on Dot11Radio0:
SSID [XXXXXX]:
MAC Address   IP Address      Device          Name                      Parent       State
0026.cba3.0b9f 10.10.60.12     CP-7925       SEP0026CBA30B9F self           Assoc <-----Here!
f0b4.799f.a9a4 10.10.60.10     unknown       -                              self           Assoc
ap#
I'm using the IP Phone 9971 (not CP-7925).
But the output of "show dot11 associations" command, has become "CP-7925" on Device.
What Is this by Design? Will it bug or?
Thank you very much in advance.
Shigeru Kubota

Hi, Kayle
Thanks a lot for replay.
I am using an autonomous access point.(AP 1142)
Device firmware is the latest version.
(AP 1142 : 15.2(2)JB , CP-9971 : 9.3(2))
As with you, I'm guessing that the access point does not recognize the CP-9971 device, too.
I'll try to contact the TAC.
Thank you for your support.
Best regards,
Shigeru Kubota

Show interface - received broadcast - counter - Vlan - L2 mcast

HI All,
I have a situation where the Show interface on 7609 displays broadcast counters. I did capture wireshark but did not see any broadcast. Wireshark broadcast for 1 minute shows 20 broadcast packets where as Vlan interface shows increase at rate of 1000 per minute.
L2 Switched: ucast: 8529 pkt, 896149 bytes - mcast: 35427 pkt, 2338134 bytes
L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcast
L3 out Switched: ucast: 0 pkt, 0 bytes mcast: 0 pkt, 0 bytes
40978 packets input, 2996897 bytes, 0 no buffer
Received 35607 broadcasts (0 IP multicasts)
The doubt I have is that I am running HSRP on LAN with 5 groups and 300ms hello. This makes around 1000 hello packets per second. The L2 multicast counter also increases at almost same rate of 1000 packets per second . The received broadcast and L2 mcast counters are almost same.
Is it likely that the received broadcast also includes the HSRP hello packets destined for 224.0.0.2? but it does shows(0 IP multicast).
Can someone please confirm that the received broadcast counter includes multicast HSRP packets or is it just a coincidence. But again on wireshark I dont see 1000 broadcast packets only HSRP packets in addition to unicast traffic.
Any help or Cisco link that can prove this will also help.
Thanks
M

Found the answer.
Anatomy of RX packet counters on a Cisco Nexus 5548:
Nexus5548# show int eth1/29
RX
6387682660 unicast packets 1495485 multicast packets 164 broadcast packets
6389178309 input packets 589693485138 bytes
5146969 jumbo packets 0 storm suppression bytes
* "input" = unicast + multicast + broadcast (all non-jumbo)
* "jumbo" = frames sized 1519 bytes to the MTU bytes defined on the interface
* "jumbo" frames are counted separately from non-jumbo ("input")
* (unicast, multicast and broadcast "jumbo" frames appear to be rolled into the
one "jumbo" counter)
This can be seen another way with the 'count detail' command, correlated to "show int" output:
Nexus5548# show int eth1/29 count detailed
Ethernet1/29
Rx Packets: 6389178309 <-- input
Rx Unicast Packets: 6387682660 <-- unicast
Rx Multicast Packets: 1495485 <-- multicast
Rx Broadcast Packets: 164 <-- broadcast
Rx Jumbo Packets: 5146969 <-- jumbo
Rx Bytes: 589693485138
Rx Packets from 0 to 64 bytes: 1059418 <-- non-jumbo start
Rx Packets from 65 to 127 bytes: 6072007478 +
Rx Packets from 128 to 255 bytes: 11055520 +
Rx Packets from 256 to 511 bytes: 287107435 +
Rx Packets from 512 to 1023 bytes: 12801466 +
Rx Packets from 1024 to 1518 bytes: 23 <-- non-jumbo end
Rx Trunk Packets: 6387682823 <-- unicast + broadcast
fyi.

CISCO 2960-S/X - Packets Output in "show interface" is under reported

I have a CISCO 2960-S/X - Packets Output in "show interface" is under reported. Could I please get an explanation exactly which type of packets are being excluded from the “show interface” output packets counter. Also, is this a documented platform bug or limitation ?
Please advise.

Post the output to the command "sh version" and post the "sh interface <BLAH>" of one of the "under reported" ports.

Help with understanding the show power-injector comand

I have been battling a connectivity issue between my point to point 1300 bridges. The install is new and the distance between them is about 1881’. There is no LOS problem. I wasn’t sure if it was a power issue ie. the bridge not getting enough power so I issued the show power-injector command. What I find interesting is the difference between up interfaces. The near side bridge shows interface 4 up, were the far side bridge shows interface 4 down. I have read in the documentation, that interface 2-6 should be down, but why is the near side interface 4 up? Would this be causing my connection to be dropping? Are there any major areas of configuration I should be focusing on? The output drops on both radios are high and continue to increment. Any help would be greatly appreciated.
Near side bridge:
== Power Injector port 0 speed 100Mb/s duplex full link up enable yes
tx bytes 64009349963 tx drops 0 tx bcasts 1843004 tx mcasts 1314040
tx unicasts 56049969 tx collisions 0 tx single collisions 0 tx multiples collisions 0
tx deferred 0 tx late collisions 0 tx excessive collisions 0 tx frame disc 0
tx pauses 0
rx bytes 5872390201 rx undersizes 0 rx pauses 0 rx (<=64 bytes) pkts 23616568
rx (<=127 bytes) pkts 9328651 rx (<=255 bytes) pkts 4187726 rx (<=511 bytes) pkts 1511066 rx (<=1023 bytes) pkts 554947
rx oversize 0 rx jabbers 0 rx align errs 0 rx fcs errs 0
rx good bytes 5872390201 rx drops 0 rx unicasts 40095322 rx mcasts 103347
rx bcasts 303838 rx SA chngs 11015523 rx frags 0 rx excessive sizes 0
rx symbol errs 0
== Power Injector port 1 speed 100Mb/s duplex full link up enable yes
tx bytes 5863845662 tx drops 0 tx bcasts 303838 tx mcasts 103347
tx unicasts 39961778 tx collisions 0 tx single collisions 0 tx multiples collisions 0
tx deferred 0 tx late collisions 0 tx excessive collisions 0 tx frame disc 0
tx pauses 0
rx bytes 63836707250 rx undersizes 0 rx pauses 0 rx (<=64 bytes) pkts 6080700
rx (<=127 bytes) pkts 5492586 rx (<=255 bytes) pkts 4239466 rx (<=511 bytes) pkts 825224 rx (<=1023 bytes) pkts 1044467
rx oversize 0 rx jabbers 0 rx align errs 0 rx fcs errs 0
rx good bytes 63836707250 rx drops 0 rx unicasts 56050099 rx mcasts 428404
rx bcasts 1870745 rx SA chngs 6997560 rx frags 0 rx excessive sizes 0
rx symbol errs 0
==Power Injector port 2 link down
==Power Injector port 3 link down
== Power Injector port 4 speed 10Mb/s duplex half link up enable yes
tx bytes 265603528 tx drops 0 tx bcasts 2132298 tx mcasts 484525
tx unicasts 197535 tx collisions 0 tx single collisions 0 tx multiples collisions 0
tx deferred 0 tx late collisions 0 tx excessive collisions 0 tx frame disc 0
tx pauses 0
rx bytes 0 rx undersizes 0 rx pauses 0 rx (<=64 bytes) pkts 0
rx (<=127 bytes) pkts 0 rx (<=255 bytes) pkts 0 rx (<=511 bytes) pkts 0 rx (<=1023 bytes) pkts 0
rx oversize 0 rx jabbers 0 rx align errs 0 rx fcs errs 0
rx good bytes 0 rx drops 0 rx unicasts 0 rx mcasts 0
rx bcasts 0 rx SA chngs 0 rx frags 0 rx excessive sizes 0
rx symbol errs 0
==Power Injector port 5 is disabled
==Power Injector port 6 is disabled
Far side bridge:
== Power Injector port 0 speed 100Mb/s duplex full link up enable yes
tx bytes 5788578922 tx drops 0 tx bcasts 384075 tx mcasts 1045658
tx unicasts 38083181 tx collisions 0 tx single collisions 0 tx multiples collisions 0
tx deferred 0 tx late collisions 0 tx excessive collisions 0 tx frame disc 0
tx pauses 0
rx bytes 61019612859 rx undersizes 0 rx pauses 0 rx (<=64 bytes) pkts 5523103
rx (<=127 bytes) pkts 4764259 rx (<=255 bytes) pkts 3856512 rx (<=511 bytes) pkts 783889 rx (<=1023 bytes) pkts 978415
rx oversize 0 rx jabbers 0 rx align errs 0 rx fcs errs 0
rx good bytes 61019612859 rx drops 0 rx unicasts 52964546 rx mcasts 349746
rx bcasts 1513629 rx SA chngs 6169826 rx frags 0 rx excessive sizes 0
rx symbol errs 0
== Power Injector port 1 speed 100Mb/s duplex full link up enable yes
tx bytes 61011915687 tx drops 0 tx bcasts 1513629 tx mcasts 349747
tx unicasts 52844186 tx collisions 0 tx single collisions 0 tx multiples collisions 0
tx deferred 0 tx late collisions 0 tx excessive collisions 0 tx frame disc 0
tx pauses 0
rx bytes 5630721089 rx undersizes 0 rx pauses 0 rx (<=64 bytes) pkts 22564185
rx (<=127 bytes) pkts 8895603 rx (<=255 bytes) pkts 3983402 rx (<=511 bytes) pkts 1493247 rx (<=1023 bytes) pkts 531124
rx oversize 0 rx jabbers 0 rx align errs 0 rx fcs errs 0
rx good bytes 5630721089 rx drops 0 rx unicasts 38083221 rx mcasts 244739
rx bcasts 384075 rx SA chngs 10351904 rx frags 0 rx excessive sizes 0
rx symbol errs 0
==Power Injector port 2 link down
==Power Injector port 3 link down
==Power Injector port 4 link down
==Power Injector port 5 is disabled
==Power Injector port 6 is disabled

Hi,
Actually port on the power injector switch are in auto-duplex and auto-speed mode
you need to ensure external devices which you connected to power injector switch ports are not hardcoded in full-duplex, they needed to be in auto-duplex mode.
because in result of duplex mismatch you connection could be slow down and even ports may shutdown.
and also check both bridge with the latest firmware release
Cisco Aironet equipment operates best when you load all components with the latest version of the software.
You can download the latest software and drivers from the Wireless Downloads Page ( registered customers only) .

Show interface status (IOS layer 2switch)

Is it possible to modify the width of the column containing the description of the interfaces when I issue the "show interface status?" on IOS cisco switches?

I don't believe so but you can type show interface description if you want to see the entire description that is associated to the port.
HTH,
Edison.

NI FPGA Interface C API multithreading safe?

Hello,
I am using the FPGA interface C API to communicate with the labview software running on my NI FPGA. Some calls take quite some time to execute, e.g. reading from a FIFO when setting a long time-out. Up till now, I have been assuming that the interface was not multithreading safe. This has now become bothersome given the time-out issue described above. Simply trying does not feel right, it may take quite some time to create a 'collison'.
Is the FPGA interface C API multithreading safe? Or, more specifically, can FIFO reading-related functions be called in parellel with writing/reading of variables on the FPGA?
Thanks.
Solved!
Go to Solution.

Hello MKAP,
It has been a while since I have used the NI FPGA Interface C API, but this is what I remember and seem to be able to recollect (and also found back in documentation):
The functions related to the unloading and loading of the library are not thread safe:
http://zone.ni.com/reference/en-XX/help/372928D-01/capi/functions_required/
On itself this should not cause a problem:
You application should force that the NiFpga_Initialize is called before all other function NIFpga related function calls.
In a similar way the unloading (NiFpga_Initialize) lof the NiFpga brary should only happen when you're done using it.
Regarding multithreading you should also keep in mind the single-threaded character of IRQ Interrupts (If you plan to use them):
http://zone.ni.com/reference/en-XX/help/372928D-01/capi/functions_interrupt/
Kind Regards,
Thierry C - Applications Engineering Specialist Northern European Region - National Instruments
CLD, CTA
If someone helped you, let them know. Mark as solved and/or give a kudo.

Show ip interface brief

Just a quick question that I have been unable to find the answer to on the net.
I ran the "show ip interface brief" on one of my 3550 switches.
Under the "method" column I have some interfaces saying "NVRAM" and some saying "manual" Can anyone explain what the difference between the "manual" and "NVRAM" setting?
Thanks,
Craig.

Yes, i believe its how your interface obtains its IP address although i don't know how the device differentiates between manual and NVRAM.
Here are the possible values:
The method field has the following possible values:
RARP or SLARPReverse Address Resolution Protocol (RARP) or Serial Line Address Resolution Protocol (SLARP) request
BOOTPBootstrap protocol
TFTPConfiguration file obtained from Trivial File Transfer Protocol (TFTP) server
manualManually changed by CLI command
NVRAMConfiguration file in nonvolatile RAM (NVRAM)
IPCPip address negotiated command
DHCPip address dhcp command
unassignedNo IP address
unsetUnset
otherUnknown
HTH
PJD

Clarification on the SHOW TOP command

Does anyone know much about the Show Top command? I am trying to get specs on the bandwidth utilization of a port. When
I do the Top command it tells me a percent of utilization. However it looks to be too low. I verified the util using a traffic generator test set and it has results of almost double the util. that the Top command stated. So my thoughts are that if the port is set for 100/Full then the Top stats for Util show only half Dux. Is this so??? I think that I need to double the Top results for util and that will be the true Util for the port. Can anyone verify this????

you are kind of correct, that it will look like a half duplex utilization because process actually bundles the TX AND rx into the same counter and it also looks at the full duplex bandwidth when calculating the % utilization. So a GE port is really 2000Mbps full-duplex. so, from the traffic generator you are sending at line rate of 1 Gig, the TOP will see that as 50% utilization. Does that make sense. This is how I understand it.

My contacts are not showing up on the PC app or the web interface. Why isn't this working?

My contacts are not showing up on the PC app or the web interface. Message+ works fine on my Note 4 though. My contacts are saved in my Google account.
I've tried several things but message+ acts like there are no contacts in the app yet there are names and pictures in my conversations. Can anyone help me?

matthttam,
Let's make sure that we get you up and running with no issues. I want to make sure that we are on the same page. Are your contacts actually listed in the address book on your phone? Are you using Verizon Messages? Or the third party Messages from the Play Store? Please keep us posted.
KevinR_VZW
Follow us on Twitter @VZWSupport

Why are my installed extentions on FF 5.01 suddenly not showing up in the add-ons window tab (to change preferences), even though the extentions (like Google toolbar and Awesome Screenshot) are visible on the FF interface?

My Google toolbar was working fine earlier this morning. A few hours later, the search window stopped opening new tabs. I did some snooping and discovered that none of my extension add-ons were showing up in the add-ons tab. However, the appearance and plug-ins are still listed. When I click on the Extensions tab there is just a small box that says "You don't have any add-ons of this type installed." However, my Google toolbar, Add Blocker, and Awesome Screenshot etc. is still visible in the FF interface. When I try to uninstall the Google toolbar using the options button on the toolbar itself, nothing happens. What's up?

Same solution as dplavin. Thanks!
Afterwords there were some changes in Add-ons that were enabled/disabled that then had to be straightened out.
I disabled Test Pilot which was in the process of testing thinking that it might have had something to do with the problem. I have not updated to the latest version of 5.0 because one favorite Add-on [Firegestures] is supposed to be incompatible.

Is the "show interface brief" command 100% safe?

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