Unreliable networking

[cpjitservices]

Hi, to be honest if that port is for management only then like every other switch that port wont need any setting up, if it did then that would be a poor build of switch as you need this port to initially first time set it all up set ip's and vlans etc etc and setup telnet access, without this port your switch is not configurable. You should be able to plug in a console cable or rollover cable to that port to the serial port of your PC and access the switch via hyperterminal or by the specified IP.

 

If fluke has detected a problem with that port then I would say that switch is fubared and personally I wouldn't put it anywhere near any of the production network it'd be in the a nearby skip, I'd seriously not waste your time and get another switch, if a console port on a cisco router or switch goes down unless telnet is enabled it's useless so I'm guessing with your switch it won't be that much different.

 

Since no traffic goes through that port unplugging stuff and plugging it back in wont affect anything on that particular port as no traffic goes through it, it could be a CPU spike that stops access to that port in which case, try unplugging everything power it down wait 2 minutes power it back up and see if fluke still detects a fault with that port.

 

Hope this helps buddy, good luck!

[SYNACK]

If the network company is a tad evil and want to keep you tied into their services they may well have disabled the hardware managment port and only be allowing managment of the switch through the ip interface. We had a managed services company that helpfully did that to a couple of schools that I ran across and it was rather the opposite of endearing when you needed to go through three layers of help desk to get a port fowarded on your own router. I would check with them to see if they have disabled it and if not RMA the thing.

[ndart]

Cheers mate that's really good adivice. I'll do this tonight me thinks...

 

Hi, to be honest if that port is for management only then like every other switch that port wont need any setting up, if it did then that would be a poor build of switch as you need this port to initially first time set it all up set ip's and vlans etc etc and setup telnet access, without this port your switch is not configurable. You should be able to plug in a console cable or rollover cable to that port to the serial port of your PC and access the switch via hyperterminal or by the specified IP.

 

If fluke has detected a problem with that port then I would say that switch is fubared and personally I wouldn't put it anywhere near any of the production network it'd be in the a nearby skip, I'd seriously not waste your time and get another switch, if a console port on a cisco router or switch goes down unless telnet is enabled it's useless so I'm guessing with your switch it won't be that much different.

 

Since no traffic goes through that port unplugging stuff and plugging it back in wont affect anything on that particular port as no traffic goes through it, it could be a CPU spike that stops access to that port in which case, try unplugging everything power it down wait 2 minutes power it back up and see if fluke still detects a fault with that port.

 

Hope this helps buddy, good luck!

[ndart]

Thanks SYNACK. I'll play with the fluke tester tonight and if no go I will order a new switch I think, only a Cisco or HP. Also, I think I will contact the network company about the switch and Management Port too. Thanks

[ndart]

Latest UPDATE

 

We successfully tested and reset the switch yesterday and found some interesting things:

 

Even after isolating the switch from the network by removing ALL links and then just inserting ONE link with transceiver we started to get the rapid traffic. It didn’t seem to matter which link we plugged in the switch exhibited this issue. Also, during the exercise, the other 9924 below was continually exhibiting this rapid packet traffic transfer as usual and was NOT affected by the removal of all those segments! This is good news for one thing and maybe bad news for another!

 

The good news is that I think this proves that there doesn’t appear to be anything looping on our network.

 

The bad news is (I think) that the AT switches may be transferring bad packets and taking ports out instead of dealing with them in a timely fashion. It might be possible to configure the switch to do this if only I could only get the management ports to work on them; whether this port has already been set up and somehow disabled I don't know. In any case this may be a fault with both switches as I have tried to link to both without success! I have contacted the company to look into this and we'll wait and see what happens there I guess. For the next week I am doing power tests to verify a hunch I have about power surges. Postulating an idea that when a power surge or brownout occurs, although the switch in that segment is proteccted by a Smart UPS the client PC in that segment isn't. My idea is that maybe the spike or surge will generate a bad packet or two which will be sent to that switch, the switch cannot handle it so it stops the port recieving. Just an idea that fits the facts but an interesting one...

 

Will keep all updated and many thanks to everyone for your commend and suggestions so far.

[paulfinlay]

I'm not familiar with AT switches but if they are like 99% of other enterprise switches the management port needs to be connected to with an RJ45 console cable and then access the switch using hyperterminal, teraterm or putty. The management port general isn't an ethernet port and you won't get link activity on it

[ndart]

In answer I am not sure whether this switch needs configuring with an RJ45 to DB9 connector or not. In any case, we have no netbooks or laptops with a Db9 or RS232 as these have dissappeared in recent years. The hardware manual is soemwhat confusing because one section says it needs a DB9 - RJ45 cable to set this up and then in the next section is says this:

 

"Out-of-Band Ethernet Management Port

The out-of-band 10/100/1000 Mbps Ethernet port is dedicated to management

traffic on the AT-9900s switch. Use it for initial configuration and on-going

management tasks. The default IP address for the port is 192.168.242.242 to

allow remote access. This port is reserved for management only; the switch

does not transmit frames between this port and switch ports."

 

So PASS, anybody else have dealing with AT-9924SP switches?

[ndart]

*** UPDATE ***

 

We have managed to get two new switches and I have replaced one of them and the issue seems to have gone (so far).

 

The core switch that I have been able to connect to, seems to be operating in within normal thresholds. For some reason although I have set up the switch via telnet and successfully connected to it I cannot HTTP into it! The sister switch, no issues at all. I will reset the non-connectable switch tonight and try again.

 

I found out that you do indeed need a RS232 or DB9 to RJ45 cable in the end. I got one with my new 8000 switch and was able to utilise this. I cannot believe that our networking company did not leave this for us.

 

I have also set up IP's on the rest of one of our more problematic segments and been able to test these switches. Early indications are that nothing untoward it going on.....the plot thickens I think.

 

Anyway, thanks everybody for the help with these issues and to Paul above too...

[plexer]

The out of band management port is a standard ethernet port, configure your laptop with a suitable ip address and connect it to that port, it is not a serial port.

 

Ben

[ndart]

...Yes thanks for that. Actually I agree, this should be as you say and Out Of Band port. Strangley though it work as a serial port. I have now (using it this way) set the switch up to be accesible from HTTP requests from an IP in our subnet range. One of the 9900 series switches has done this correctly, but this one refuses to connect. I have ensured and double checked that the config file is there and that the HTTP server is running as well as the IP is pingable and it is. Any ideas?

 

The out of band management port is a standard ethernet port, configure your laptop with a suitable ip address and connect it to that port, it is not a serial port.

 

Ben

[ricki]

HI

 

Try the default username and passwords for the switches a lot of installers dont set passwords.

 

Richard

[ndart]

Hey guys. Sorted!

 

Thanks for all the help with this you guys here and this resource is ace.

 

The fix was complex but worked:

 

1. Replaced one failing switch on one segment

2. The older of the two switches could not access it's own GUI because it didn't have one....doh. The original system had no GUI and I about to flash one onto it!

3. The switch is operating normally anyway.

 

So the main issue was a failing switch on another segment on the same subnet! So far so good, looking calm.....

 

lol

[mike_irvin]

do you know what the fibre is that you are using in the backbone? ie multimode, singlemode and how old it is? some old fibres had a service life and would possible not support Gbit, as they are aging this can cause elements to drop out, if you are also expericening issues on brown outs this could also means that the actual light levels are low and then the loss across the cable could be too great for the switches to interpret. It maybe worth getting the link tested for performance as a link using a tester such as a Fluke or ideal tester which can check against an agreed standard, I would suggest either TIA 568c or ISO 11801 which would confirm if the fibre backbone could support Gbit.

May prove more cost effective that changing the switch and less distruptive as if required the new cables can be run, terminated, tested, then out of hours crossed patched over.