Comments on: Clock rate and Bandwidth commands

By: Joe Mendola

Joe Mendola — Mon, 23 Jan 2012 13:36:26 +0000

@Jay first of all thanks for your reply and research.
Im using packet tracer and GNS3. I didnt try the 3845 IOS. At least now i know it is tied up with the platform of the device im using with.
Your comment has been very useful for me
later

By: Jay

Jay — Mon, 23 Jan 2012 13:20:46 +0000

@Joe – What router are you using? As a guess is it a 1600 / 1700 series router?

I’ve run some tests on 4 different router models in the last few minutes and I’ve noticed the problem you are referring to on the lower end models, 1600/1700 series models.

On a 1721 I get the following output

DTE V.11 (X.21) TX and RX clocks detected

but as you have said, I cannot see the exact clockrate that I’m receiving…

On a 3845 I see the following

cable type : V.11 (X.21) DTE cable, received clockrate 64000

When displaying a show run, there is no clockrate command under that interface. This is the same result I’m getting for the other 16 serial interfaces on this router. This 3800 series router is not running any advanced images

Cisco IOS Software, 3800 Software (C3845-IPBASE-M), Version 12.3(11)T7, RELEASE SOFTWARE (fc3)

It would seem as though the lower end models don’t have a quick way to identify the received clockrate from your provider. If I do manage to find a command that will give you this info, I’ll be sure to post it here

By: Joe Mendola

Joe Mendola — Fri, 20 Jan 2012 14:19:54 +0000

of course there is an error in what i wrote before: i meant “show controllers int se0/1 for instance ”

it has to be a SERIAL int; im sorry for the mistake

By: Joe Mendola

Joe Mendola — Fri, 20 Jan 2012 14:16:03 +0000

@Jay
show controllers int fa0/1 for instance, helps you to see if you have the dce or the dte cable attached to that interface….then you can likely issue the clock rate command if you discover on that interface it is keeping the DCE cable !
the command does not show the current value of the speed.
I found only this thing: afterwards you issued the command clock rate on an interface, you can read the value you inserted, just with the show run command: under the specific interface, you can read the value of the clock rate.

I have not found anything that can let me discover the current clock rate value, before i usethe clock rate on an interface

By: Jay

Jay — Fri, 20 Jan 2012 14:05:13 +0000

@Joe – “show controller” is the command you can use. This is the same command I’ve used in the screen shot above.

By: Joe Mendola

Joe Mendola — Fri, 20 Jan 2012 08:57:40 +0000

what is the IOS command that allows to read the current clock rate value?

By: Onesphor

Onesphor — Thu, 17 Nov 2011 19:42:04 +0000

Very helpful!!!!!!!!!!!!!!!!!!!!

By: Jay

Jay — Tue, 18 Oct 2011 14:48:16 +0000

Hi Gaurav,

Boson is a simulator, so sadly it does not have every command programmed to do something. Assuming you are typing the “clock rate 64000″ under the interface, then Boson doesn’t’ support the clock rate command.

Although Boson used to be the number 1 program for learning Cisco commands, it’s been overtaken a few years ago by Dynamips. Otherwise known as Dynagen or GNS3. It is an emulator not a simulator so it accepts ANY commands you throw at it as long as the IOS you have loaded supports the command. Best of all, it’s free… you just need to get your hands on a IOS.

Hope this helps.

By: Jay

Jay — Tue, 18 Oct 2011 14:43:13 +0000

Hi Fernando,

Is this a 1600 series router? If not, please tell me which Router modem as well as the IOS that is running on the machine.

Regards,
Jay

By: Fernando

Fernando — Fri, 14 Oct 2011 10:25:46 +0000

Hi Jay,

First thanks for your article.

Second, I am afraid I can not get the clock rate from the show controller command. Here is my output:

Interface Serial0/0/0
Hardware is GT96K
DTE V.11 (X.21)idb at 0x42CEDEFC, driver data structure at 0x42CF5CE0
wic_info 0x42CF6264
Physical Port 1, SCC Num 1
MPSC Registers:
MMCR_L=0x000300C0, MMCR_H=0×00000000, MPCR=0×00000100
CHR1=0x00FE007E, CHR2=0×00000000, CHR3=0×00000648, CHR4=0×00000000
CHR5=0×00000000, CHR6=0×00000000, CHR7=0×00000000, CHR8=0×00000000
CHR9=0×00000000, CHR10=0×00003008
SDMA Registers:
SDC=0×00002201, SDCM=0×00000080
CRDP=0x0FA40840, CTDP=0x0FA427A0, FTDB=0x0FA427A0
Main Routing Register=0×77777707 BRG Conf Register=0×00490018
Rx Clk Routing Register=0×00000080 Tx Clk Routing Register=0×00000090
GPP Registers:
Conf=0×50055600, Io=0×50055600, Data=0xFFFFFBFF, Level=0×00001800
TDM FPGA Registers:
vmcr[0] = 0×00010040, vmcr[1] = 0×00000000,
vmcr[2] = 0×00000000, vmcr[3] = 0×00000000
ntrcr0 = 0×00000000, ntrcr1 = 0×00000000
tdmcr = 0x0000006A, labcr = 0×00000000, tpllr_cr = 0×00000000
nhr = 0×66666660, isr = 0×00000101, imr = 0×00000000
548594 input aborts on receiving flag sequence
0 throttles, 0 enables
160506 overruns
0 transmitter underruns
0 transmitter CTS losts
27681337 rxintr, 20399892 txintr, 0 rxerr, 0 txerr
46592550 mpsc_rx, 183 mpsc_rxerr, 7174 mpsc_rlsc, 357504 mpsc_rhnt, 46258388 mpsc_rfsc
1482 mpsc_rcsc, 0 mpsc_rovr, 183 mpsc_rcdl, 0 mpsc_rckg, 0 mpsc_bper
2 mpsc_txerr, 2 mpsc_teidl, 0 mpsc_tudr, 2 mpsc_tctsl, 0 mpsc_tckg
0 sdma_rx_sf, 976 sdma_rx_mfl, 160506 sdma_rx_or, 548594 sdma_rx_abr, 406125 sdma_rx_no
0 sdma_rx_de, 183 sdma_rx_cdl, 837621 sdma_rx_ce, 0 sdma_tx_rl, 0 sdma_tx_ur
0 sdma_rx_reserr, 0 sdma_tx_reserr
0 rx_bogus_pkts, rx_bogus_flag FALSE
0 sdma_tx_ur_processed

It is supposed that the line is 512 kbits/second but I can not confirm it with the output.

Kind regards,

Fernando.