LAN DRAG Then Stall

[dennycsr]

I have a router - network problem that hopefully you can assist me with.

The client has a Cisco 800 Series on a LAN attached to an ISDN line heading out and a 3-com 24 port hub inside. It is not a switch. After I set it up with about 12 users, all worked fine. No access problems or shutdowns. I just found out that they have been experiencing "lock-ups" and huge degradation in performance for the past 60 - 90 days. I went through the possibilities and found that 4 new nodes have been added since I left and one unit was moved.

"Someone" added 3 PC's and 1 Xerox copier to the network. I can only guess that the Copier was set correctly as TCP/IP but no one could tell me the address. One PC was only moved and the settings that I config'd were not changed. The last three nodes were config'd with TCP / IP, NetBeui and IPX / SPX. I remember somewhere that the IPX / SPX constantly sends out a packet seeking information and was wondering if these settings could cause both the slow down and "lock-ups"? The CISCO engineer telenet into the system and said that the router can not handle IPX / SPX if the user was trying to get out through the router. His expanations were either 1.) Bad Cable (I tried new cables with no difference) 2.) The Ameritech ISDN line loses sync with router 3.) Bad Ethernet Port on router (Appeared to be fine after Engineer Tested)
4.) Strange packets colliding in router.

The ISDN line is a possibility but the Users "swear" that while some are locked, others have internet access. I can't dispute this but it doesn't seem likely. I can only rely on Ameritech to admit they have a problem but that will be like pulling teeth.

All this ditribe leads me to the big question O Great Guru ...
If the 3 units are set up with IPX / SPX protocol and "Client NetWare Networks" - can gremlin packets be causing the "slow down" and / or lock-up of the CISCO??

I will be meeting with this client on Monday and desire your "pearls-of-wisdom"!

 

[jeter]

Several questions come to mind? Are you getting a true 128k connection? Whats the ver of the IOS on the 800 router?
Have the new pc's and or the xerox copier been removed from the 3com to determine the latency? Have you put a sniffer on the network? Debug the router to see whats going on. Jeter@LasVegas.com
J.Fisher CCNA

 

[dennycsr]

I haven't checked the ISDN speed but when it is working there doesn't seem to be a problem. The IOS C800 Software is version 12.0(5)T Release Software (fcl). I have not removed any units as yet (I was blind sided on a courtesy call and am trying to determine what to do first). The biggest problem is another company put in the 3 units with Netware Client whereas I set everything up with Microsoft Client TCP /IP. Xerox hasn't been part of this as yet. I'm stuck in the middle of a finger pointing situation with the other vendor. The logic of "the system worked fine for 4 months after I completed the contract and now there is a problem after new variables were introduced" seems to fall on deaf ears. Will the Netware cause disruptive broadcast apckets if the router will not accept them due to the configuration?

Thanks again.. I'm meeting with them on Monday!

 

[jeter]

Finger pointing, I know that all to well. I agree with you have them remove the new equipment and start testing from there. Good Luck with your meeting. Jeter@LasVegas.com
J.Fisher CCNA

 

[trevorh13]

Netware shouldn't cause any probs from the router's point of view unless the router is configured to route IPX otherwise IPX will be isolated to the internal LAN. (The solution I use here). Netware does generate a lot of broadcast packets and this can lead to problems in larger networks but I wouldn't think it should a problem in what you describe. I have around 120 Netware clients and three servers and do not experience broadcast problems. It may be worth checking for collisions as you mentioned that all were on hubs. I found with around 15 users I was getting problems with bandwidth maxing out on the hub and so changed to a switch and things settled down. Admittingly we are a training center and students love their large downloads! If LAN access speeds are slow aswell then I would look a little deeper at the hub. It sounds to me like some fairly meaty files are either being downloaded or possibly sent to the printer.