Question in switching for STP and loop

hi ,
i have a question in loop issue , will it occur in this case or not
i will describe my scenario as below :
now i have 4 switches connected with full mesh.
=================
3 of them has stp protocol enabled
only 1 of them is un manged and dont support STP protocol
====================================
the question is :
if i connected the 4 switches full mesh , will the loop occurs ??
as i believe , stp loop prevention depend on the switch itself not on their neighbour , but not sure from my understanding
wish to help
regards

Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
If there's only one or two non-STP switches, in a full mesh, you'll be okay. Once you have at least three non-STP switches, in a full mesh, you have a loop between them.

Similar Messages

I just finished creating a movie in IMovie and now want to burn it to a DVD and make it loop. Since I just purchased this IMac it no longer comes with IDVD. My question is how to burn and loop a dvd without IDVD. Thanks for any help.

I just finished creating a movie using IMovie and want to burn it to a DVD and loop it. Since I just purchased this mac it looks like they no longer include IDVD. Is there something out there to help me do this. I am new to MAC and any help would be greatly appreciated. Thanks

There is free open source software called Burn that will burn DVDs. Here is a link.
If you wish to pay for software, there are many, including TOAST TITANIUM from Roxio. Apple's retail copy of iLife 11, and Apple's Compressor.
Of these, I would say that iDVD is known for being able to create very professional looking DVDs with intros, menus, lots of interesting templates.
Toast is much simpler and the menus and templates are more plain.
Compressor is a professional tool that does a lot more than make DVDs. Don't expect much in the way of menus or templates.
Burn, I have never tried, since I have iDVD and Toast for those ocasions when I need to burn a DVD. However, since it is free, I think it is worth a try.
Each software package is a little different, but in general, in iMovie, you can use the SHARE menu to SHARE/MOVIE in Large size. Save the movie to your desktop or someplace you can easily find it. Then drag it into the tool of your choice. You can alsouse SHARE/MEDIA BROWSER/LARGE if you have iDVD or Toast.

Question regarding material for Forms and Reports

Hi, I'm good at SQL, now that i would like to learn Forms and Reports in Database. But i dont know like where to start and how to start. Could someone please help me out like what i need to do to learn them. As i said i'm very much new to these concepts.
Thanks in advance

Hello,
if buying abook is an option for you and you are speaking german I would advise you to get
Perry Pakull, Stefan Jüssen, Walter H. Müller:
"Praktische Anwendungsentwicklung mit Oracle Forms", HANSER Verlag ISBN-10: 3-446-41098-8. Have a look at
[http://www.hanser.de/buch.asp?isbn=978-3-446-41098-5&area=Computer|http://www.hanser.de/buch.asp?isbn=978-3-446-41098-5&area=Computer]
Regards
Mario

Question. CC for Lightroom and Photoshop and, in say 5 years or so, become inactive.

What access would I have to my photos if I sign up for CC for Lightroom and Photoshop and then become only an occasional user. Will I still be able to find my photos using Lightroom? Will I be able to search for photos using keywords? Will I be able to see metadata?
Thanks.
Fritz Schafer

Dave Merchant wrote:
If you stop subscribing, the software stops working.
This aspect is indeed going to be a rude awakening for many users some day.

STP and Loop Guard

Hi everyone, I've a question for you guys:
Please check this topology: http://www.cisco.com/warp/public/473/84d.gif
I've read that you must enable loop guard on every nondesignated port (root and alternate ports) to prevent unidirectional related loops. I understand the situation where switch C unblooks the AP port and cause a loop. But what if the link is not unidirectional, what if switch B has some problem and indeed switch C should forward traffic to the segment C-B? Is there a difference between the link going down (disconected)and just stop seeing BPDUs?
Also, why would anyone configure loop guard on a root port? If for example, SWC stops seeing BPDUs from SWA, what would loop guard do? put the port in a block state or it would recalculate its Root port (port to SWB) and put the port to SWA into a designated state (after not receiving BPDS from SWA)? I'm very confused, any help would be greatly apretiated.
Omar Montes

The assumption made by STP is that if a link is not able to transmit BPDU, it is down. So if there is bidirectional link failure, the case is natively handled by STP. If there is only unidirectional link failure, you could end up with a unidirectional loop (which is about as bad as a bidirectional loop;-))
Loopguard is relevant on each port that is supposed to continuously receive BPDU. If your root port stop receiving BPDU, STP will move it to designated and elect a new root port. This is ok if your old root port cannot receive and transmit traffic. However, if the link is unidirectional and the port does not get blocked by loopguard, you will have a loop through the old and the new root port (in one direction only, the old root port TX direction).
Configuring loopguard on a designated port will not cause any problem anyway, so in fact you can configure loopguard blindly on all the port.
The IEEE introduced a feature (the dispute mechanism) that works much better than loopguard in order to protect against unidirectional link failure. However, this mechanism requires an RSTP bpdu format. It is currently only implemented in MST on cisco switches (it will be soon available in rapid-pvst). No need to use loopguard with the latest MST code at least.
Regards,
Francois

Question about switching DPS accounts and In-App Purchases

Here comes a tricky one
I have my app published on Apple using an specific DPS account (aka [email protected]) and I have some in-app purchases into the app that the final users have already bought.
For some reason, I need to switch the app to use a different DPS account (let's say [email protected]) and I need to recompile the app and make it available on App Store (Apple Account will be the same one). Concerning the folios, I can upload them again with the same product ID as the older ones and delete the older folios from the older account.
Question is: What would happen to my In-App Purchases? Will I be able to restore my purchases if I have a new app with a different account? Will Adobe allow to use the same Product ID for another folio even if it was used previously?
Hope you can help me out with this.

Phone is now fixed and because the game was saved to my game centre, it loaded with all purchases. So I'm thinking that as long as the game is saved to game centre, it will reload as it was previously.

Which switch for POE and 7940G phones?

I have 2 (and maybe soon 5 more) 7940G phones to add to my network, which already has a Netgear POE capable switch. I've since discovered that early Cisco POE isn't the same thing as current POE, and the switch doesn't power the phones.
I was looking at adding a Cisco SD208P 8-port switch to power the phones, but I soon discovered it only has 4 POE ports, and I'm not sure that this switch will even power the 7940G phones. And if the other 5 phones show up, I'll need two of those switches with no room for expansion on the voice network.
Will this switch power those phones?
Is there another small switch available so I don't have to replace my existing switch infrastructure to get these phones to work? Or do I need to scrap the phones and get something newer that will work with the current POE standards?

Will,
I would look at the ESW520 8 port switch, it will power the phones and will have the "*" VLAN's already setup in them.
Side note "*": This assumes that you are using VLAN100 and Cisco Voice system for the switch
Have a great day

FC switch for xsan and xgrid!

Hi,
Can somebody suggest me any swithc which will work with Xsan and Xgrid (over mac pro 5.1 FC card - lsi7204ep) with 20 port, 8 port default active?
P.S.
One interesting thing is that on LSI home page this card (lsi7204ep) has no support to Mac OS, however it's lates that come with Mac Pro 5.1!

Go with the QLogic devices. I've had good success with their products from the 5200 on up. Some units have dual power (which saved my bacon). If your sales rep tries to sell you the enterprise management suite say no thanks. I've been able to do everything with the built in web management tool.

Wait for an agent with best skill and loop after that.

I want to solve the following situation:
I have three skills (A, B, C) with different skill levels for each agent. C is the "everything else topic" . The caller selects the toppic which is equivalent to the skills. Of course I want the call to be forwarded to the best skilled agent.
Let's assume the calles selects topic A and all Agents with Skilllevel > 5 for A are currently talking. I want to hold the caller for 30 seconds to wait for one of these Agents. After 30 seconds I would like to forward the call to the agent with the highest skill level A.
And of course I want to avoid the caller to wait the 30 seconds if no Agent with skilllevel > 5 is on duty.
Currently I have one CSQ for each topic and I expect a skillevel > 5 for the agents serving this CSQ.
At first I put the call in the CSQ for A and play a prompt with 30 seconds MOH, if no agent becomes available I put the call in the CSQ for C and loop the caller there. But now the best agent for C get's the call.
I appreciate any hints on that.
Christian

Don't queue in C unless there are at minimum X ready agents. You can define X as 1 to start, then play with the number to see how it affects wait times and dequeues.
select resource (csq_a) connected end queued label loop ready_in_c = get reporting stats(csq_c, ready resources) if (ready_in_c >= 1) true /* at least one person idle and ready in C select resource(csq_c) connected end queued /* oops! we just missed them. */ /* if ready_in_c was > 1, this dequeue step will not execute */ /* instead, the script jumps to the select resource step for csq_c */ /* and tries the next agent automatically. only when there are no */ /* idle and ready agents do we dequeue the caller, so that an agent */ /* servicing csq_a can take the call */ dequeue(csq_c) false /* no one available in C */ play prompt(you are important to us) call hold delay 30 call unhold goto loop

Syslog level 6 on 65xx for sys and spantree

Hi
Cisco's Best practices doc for 4xxx, 5xxx and 6xxx series switches states to up the logging level of both sys and spantree to 6.
http://cisco.com/en/US/products/hw/switches/ps663/products_tech_note09186a0080094713.shtml#sl
I am finding it hard to find what extra information you get with these non default logging levels.
I am particularly interested in sys
Cisco - "Cisco generally recommends bringing the spantree and system syslog facilities up to level 6, as these are key stability features to track. "
If anyone knows what extra features you get that could provide extra stability be that by proactive notification please let me know. Or for that matter what you could miss by leaving at default of 5.
Thanks
PG

Hi PG,
Logging level 6 is for informational messages and there are lot of messages which are logged at level 6 for spantree and system messages.
Like a port state in the VLAN changed to blocking which is diaplyes as a spanning tree 6 level message.
Have a look at this link for spantree level 6 messages
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_7_3/msg_gd/emsg.htm#wp1016279
A message for sys level 6 can be for ip phone like a message indicating that an IP phone is reporting a problem with the inline power it is receiving on a port.
Have a look at this link for all sys level 6 messages
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_7_3/msg_gd/emsg.htm#wp1016897
I think this will give a fare idea what all messages at level 6 for STP and SYS will let you fast analysing and can result in fast recovery of possible arising problems.
HTH, if yes please rate the post.
Ankur

JSF conditions and loop

Dear programmer
I'm new to JSF. I have almost finished to read all the tutorial and there is something that bothere me. In all the the examples, there is no use of condiion statements (if) or loops (for, while). How is it possible to program without them?
I guess that with renderer I can do things that I could do with if statement and with UIData component I can create loop, but is it enough? It seems very odd to me that there are no conditions or loops.
(Or maybe there are and I just not aware to it)
For example I have a frame that is compounded from 2 forms. The first enable to user to search something. The second shows the results. I don't want the form of the results to be shown if there are no results. Can it be done with renderer?
In order to show the results I need a loop. Is UIData enough?

I have a frame that is compounded from 2
forms. The first enable to user to search something.
The second shows the results. I don't want the form
of the results to be shown if there are no results.
Can it be done with renderer?
In order to show the results I need a loop. Is UIData
enough?rendered="#{myBackBean.resultsAvailable}"
You should have had more extensive JSF tutorial or an introductory book.
I recommend Hans Bergsten's JavaServer Faces from O'Reilly, in which you could see
many example code for conditionals and loops without using 'if', 'while' nor 'for'.

ERROR -- Checksum error for Hidden and Protected item ID

Hello all,
I usually get the error:
Checksum error for Hidden and Protected item ID (10785219011206310), value (on), posted checksum (C1DEF33B4C8D57845151B7D18363B3D7), expected checksum (********************************), index_i (3), index_j (2), index_m (1);
I have already found one thread with this question - Checksum error for Hidden and Protected item ID
but there are no answers to this problem.
Any thoughts how to solve this and what is causing it??
Regards Pedro.

Pedro,
Read under the improved security section in the below article.
http://www.oracle.com/technology/products/database/application_express/html/3.1_new_features.html
I used to receive the same error because I was trying to update the value of the hidden and protected item on the same page repeatedly.
I changed the item type to hidden to avoid the error.
Hope this helps,
Dippy

Different physical networks for public and private IPs ?

Hi,
My ISP router, public sides and private sides of my servers are all plugged on the same switch. I was wondering if the troubles I experience with my home directories server, hanging all services very often, can come from that config. Does it make sense to usse different switches for public and private IPs ?

It's a good practice to put external and internal traffic on different switches or, at least, on different VLANs on the switch to segregate the traffic.
However, it's unlikely to cause the problems you describe unless there's something wrong with the network (e.g. it's overloaded or experiencing some kind of broadcast storm.
If you have a separate switch it's worth trying. Without knowing the make and model of your switch it's impossible to tell whether VLANs are a viable option for you.

7344 servo motion switching between open and closed loop operation

I have a custom end-of-line test system presently using a 4-axis 7344 servo controller to perform various functional tests on small, brushed DC motors. The system is programmed in C/C++ and uses flex motion functions to control the motor during testing. Motors are coupled to external encoder feedback and third party PWM drives running in closed-loop torque mode from an analog command signal. The system uses all four motion axis channels on the 7344 board to independently and asynchronously test up to four production motors at a time.
In closed-loop mode, the system runs without issue, satisfying the battery of testing protocols executed by this system. I now have a request to add additional test functionality to the system. This testing must be run in open loop mode. Specifically, I need to use my +/- 10v analog output command to my torque drive to send different DAC output levels to the connected motor.drive while monitoring response.
I do not believe the flex motion library or 7344 controller includes functions to easily switch between open and closed loop mode without sending a new drive configuration. I am also under the impression that I cannot reconfigure one (or more) servo controller axis channels without disabling the entire drive. As my system runs each axis channel in an asynchronous manner, any requirement to shutdown all drives each time I change modes is an unworkable solution.
I am open to all ideas that will allow asynchronous operation of my 4 motor testing stations. If the only solution is to add a second 7344 controller and mechanical relays to switch the drive and motor wiring between two separately configured servo channels, so be it. I just want to explore any available avenue before I place a price tag on this new system requirement.
Bob

Jochen,
Thank you for the quick response. The 7344 board does an excellent job running my manufacturing motor assemblies through a custom end-of-line tester in closed loop mode. A portion of the performance history and test result couples the motor through a mechanical load and external shaft. The shaft is in contact with a linear encoder that closes my servo loop.
My new manufacturing requirement is to also sample/document how the small DC motor behaves in open loop operation. Your solution is exactly what I need to perform the additional functional tests on the product I am manufacturing. I see no reason why this cannot work. I was originally concerned that I would need to reinitialize the 7344 board after changing axis configuration. Initialization is a global event and impacts all four channels on the 7344 board.
Using flex_config_axis() to change axis configuration on a single channel without disturbing other potentially running axis channels will solve my concern. It will be several weeks before I can return to the manufacturing facility where the 7344-based testing machine is located. I will update this thread once I verify a successful result.
Bob

I am using Mail for emails and I seem to have two different windows that switch between the two. The emails are the same but the second window opens when I click on any details and I cannot see the top of my screen with control icons for internet, file

I am not very tech savy and apologize in advance if my question is not clear. I use the Mail application on my mac and I have two users on my computer, one for gmail and another for my work email. All email addresses appear in the mail application on one page. When I open my email and click on a message it often goes to the other user screen and cuts off the top of my screen which shows the bar for Chrome, file, edit, view, history etc....Still functional but very annoying. How do I choose a user screen and stop having it switch back and forth.
Thank you.

Mail troubleshooting - Yosemite
Troubleshooting sending and receiving email messages
Troubleshooting sending email messages
SMTP servers keep going offline

Question in switching for STP and loop

Similar Messages

Maybe you are looking for