Mvp 8400 Falling Offline

gregbentley

I have a MVP 8400 that is falling off line almost every evening, and definitely every weekend. I have instructed the customer to powerdown the rack ( NI 3000, and Linksys 802.11b router in the rack ), and then the panel is back online and every thing works again. The System consists of the NI 3000, Linksys 802.11b 4 port router ( Static ips for panel,master and local PC running AMX computer control, latest firmeware in master ,TDS, and MVP),and an MVP TDS. To trouble shoot I have 1: turned the Panel Shutdown to 0 in the MVP so the panel will never shutdown. ( they keep it docked always so batteries draining is not the issue ) 2: provided a button on the first page of the panel tied to a Data_Event to match the online/offline state of the Panel. When the panel is offline the button correctly displays the offline state. Friday I was on site to witness the problem ( system not working and button on panel correctly indicated the panel was offline) and a reboot of the Router ONLY fixed the problem. So I was really thinking router problem, but left the system status quo and working Friday night to see if the problem was still fixed by rebooting the router only. I heard Monday that the panel was off line as usual Monday morning, they rebooted the router ONLY, waited 3 minutes, and the panel DID NOT come back online. They had to powerdown the rack ( which again rebooted the master and router ), then the panel was online. Is it still the router? I am leaning towards the router, but could it somehow be the panel or the NI?

DHawthorne

The very first thing I would do is run a notifications check and see how much traffic is going back and forth to the panel. I am finding more and more that this is critical and needs to be optimized even in what I consider a basic system. I also run a packet sniffer (Ethereal works very nicely, you can Google it for the download site), to see what devices are generating more traffic than I like.

Excess network traffic is far more critical when you add wireless to the mix, and crops up again and again as a trouble spot for me.

Spire_Jeff

Originally posted by DHawthorne
I also run a packet sniffer (Ethereal works very nicely, you can Google it for the download site), to see what devices are generating more traffic than I like.

Two things, first... I Have had nothing but trouble with Linksys routers and access points. The problems with them are compounded when you have multiple access points on the network. So, I would definately be suspect of the Linksys device (you might try getting the latest firmware from Linksys)


As for packet sniffing, you have to be careful of how you are sniffing the packets. If you are sniffing from a switch, you will be missing a lot of the network traffic (Unless you have a higher end switch that lets you send all traffic to a specific port). To get a true picture of the traffic, the easiest thing to do would be to temporarily replace the switch with a hub and run the packet sniffer.

Jeff

DHawthorne

Originally posted by Spire_Jeff
As for packet sniffing, you have to be careful of how you are sniffing the packets. If you are sniffing from a switch, you will be missing a lot of the network traffic (Unless you have a higher end switch that lets you send all traffic to a specific port). To get a true picture of the traffic, the easiest thing to do would be to temporarily replace the switch with a hub and run the packet sniffer.

Jeff

You can run Ethereal in promiscuous mode and it will pick up everything on your subnet. Typically, I'm not concerned with all that, so I use it to monitor the traffic via the wireless NIC in my laptop - which gives me all the traffic that might impede upon my MVP's. Just today I used it to optimize a system - I saw a ton of stuff going from the master to the panel when the system was idle, and it helped narrow down the source because I could see the exact messages going around. I also used it at a site to uncover a vulnerability that was allowing people to relay through a mail server (wasn't my responsibility, but the person whose it was appreciated the help).

Spire_Jeff

I hadn't really thought about the wireless end, but as long as you are on the same AP as the devices, you will get everything. As far as running promiscuous mode on a switch, it shouldn't work.... if the switch is working properly. Switches maintain a list of network addresses and which port they belong to. Using this internally maintained list, the switch only sends packets out to the ports that have matching addresses. This allows for much more efficient network traffic. Obviously, broadcasts are sent to all ports, but you may be missing traffic generated by the processor if it is destined for places other than devices attached to the AP that your computer is attached to. If the customer only has wireless touchpanels and they all use the same access point, then you should be ok because wireless APs act like the older hubs and just send out everything and let the network cards pick out only the info addressed to them.(barring the processor generating a ton of traffic to a wired device or the internet). I apologize if I am recalling something incorrectly, but this is how it was when I was more involved in the networking scene.

Jeff

DHawthorne

That makes sense, the limited use I've made of the sniffer jives with both our statements. I'm not an IT guy (and don't want to become one), but in this business, you have to know a bit about everything or you are in trouble.