Cisco Support Community
Community Member

Help on connectivity issues

Okay, I have a general data com Frame Relay router connected to a frame relay switch/router and then connected to a cisco catalyst 500, which then has wired and wireless users connected. Last Friday (19th) at approximately 5:00 PM all of the wireless and some number of wired users were bumped off the network. Some users were not able to log in to an application (Summit) all weekend. I have no idea why or how access to the network was achieved Monday morning.

On Mon. the 22nd, Tue. the 23rd and Wed. the 24th the users were bumped off at approximately 5:00 PM each day. Each time the users are bumped off all of wireless are bumped off and some number of office users are bumped off.

I checked the F.R. router and the transmit and receive lights were flashing as were the RTS and CTS lights indicating that traffic was passing between the two locations. After talking to the users I discovered that not all users are bumped off each time -- there were several users who continued to access the network during this time, however, the wireless and a number of office personnel were bumped off. I powered off and then back on the F.R. router and it appeared that office personnel were then able to get back on again.

Qwest claims that they have been monitoring the line since last week and see no indication of line problems.

The I/T people tell me that the only change they have had in the last 6 to 8 weeks is that they installed a new Cisco switch to which the F.R. router and the users are attached to -- remember, this problem began last Friday, not 6 or 8 weeks ago. Is there anything in the Cisco switch that can cause a problem? F.R. router to switch connection?

I'm look for suggestions on how to narrow down or isolate the problem. Is there anything in the 2821 router that will tell us what might be happening? The F.R. routers are General Data Com units -- 56 KB. The F.R. circuit is a 56 KB circuit, not a fractional T1 circuit.

What is interesting about this problem is that it is occurring in the afternoon between the hours of 4:45 PM and 5:15 PM -- this is not consistent with hardware problems because hardware problems aren't this consistent. Can the problem be related to bandwidth?

I have the M.L. I/T person checking the F.R. router and the switch for error lights but I don't expect he will find anything. I will be contacting Qwest and see what, if anything, they can do to help isolate the problem.

Here is some more info

A. No one is turning off equipment when they go home -- he's the only one there.

B. They have two pieces of Cisco equipment connected together, and the F.R. router attaches to one of the two. One switch is a Cisco Catalyst Express 500 and he

does not know what the other piece of equipment is other than it is a router/switch combination but they are not using the router portion today. Dick will get the

model number shortly for me.

C. Dick will check the Cisco equipment and the F.R. router for error lights

Any help or info about the 2821 router would be greatly appreciated


Re: Help on connectivity issues


It reminds me of some stories about external interference with networking equipment I heard or was involved in.

1) All servers in an office building were rebooting at certain times simultaneously. Reason: new high speed train track bypassing the building. The high speed train caused enough EMI to reboot servers. (Funny: as a workaround until EMI shielding was in place every worker got a sheet with the train schedule to allow for early enough logout ...)

2) Network breakdown in a university building at the end of each leacture. Reason: Cat5 cable taped to the power cable of the elevator.

(Hey, they saved themselves a lot of drilling, didn´t they? and: Students should walk, keeps them fit!)

3) Server outage every night at 7.15 p.m. to 7.45 p.m. Reason: new cleaning personel needed a power plug for the vacuum cleaner.

(What´s wrong with that, after all she plugged it in again!)

So what happens in the neighborhood of your networking equipment at around 5 p.m.?

Just reminds me of some PWC consultants recommending "out-of-the-box thinking" ...

Hope this helps! Please rate all posts.

Regards, Martin

CreatePlease to create content