Wireless Access Point Setup Woes

Hello!
We have a allen Bradley network setup in our work place, currently we access this by a D-link Ethernet switch the old fashion cable plug into a laptop method.

I have managed find a old Linksys WAP54G access point to play around with and hoping to get this to work! Our network runs on the 192.168.0.XX range, so I have set the access point up accordingly to a static IP of 192.168.0.115 that doesn't conflict with any other Ip address on the system. The issue I'm having is I'm able to ping the access point and access it's Web GUI but once I plug it into the network i.e. into the Ethernet switch, I'm no longer able to access it or ping it, like it just goes dead. Also I'm a tad unsure what to set the default gateway too?

The objective is just to plug into the network so can access wirelessly rather than using a cable around the office. If needs must also take direct to a piece of equipment and plug in there also (on the same network).

Any ideas?

Thanks in advance

What port are you 'plugging into the network'?
If you aren't configuring that as a router, then don't use the DSL/WAN/Whatever it is called special port to connect to the network, just use one of the normal Ethernet ports and try that.

Hmm lost me a bit there I'm afraid! I've got a D-link 10/100F fast ethernet switch that we use to connect to our PLC network. I'm plugging in my WAP54G into this in hope I can then connect wirelessly.

The ethernet switch I've got is:



Without being plugged in I can connect to the wireless access point, but once i plug into the ethernet switch the access point connection is lost/very weak. It tries to pick up devices on RSlink but keeps losing them.

Right made a discovery. The ethernet switch stated above has two ethernet cables going out into our network, ethernet cable 1 goes out to 40 PLC racks, while ethernet cable 2 goes out to 6 PLC Racks so we use the ethernet switch to allow us to connect to both with no cable swapping.

Now.. to eliminate the switch to the WAP54G being the problem I've bypassed it. I connected to cable 1 and couldnt get a connection, same symptons as previously stated. However when I connected to cable 2 the connection worked great! Able to access all wirelessly. Now is there a limitation with the WAP54G on how many nodes it can discover maybe?

My guess is that some of your controllers are performing cyclic I/O control of remote I/O chassis and other devices using UDP Multicast.

I know from experimentation that most wireless access points, and the Linksys 54G access points and routers specifically, cannot handle UDP Multicast effectively and tend to "bog down" and even fault when they encounter that kind of traffic.

Generally, UDP Multicast is constrained by the use of a technology called IGMP Snooping. You need managed switches and a carefully configured network to make that work.

If this were my system, the first thing I would do is try to figure out which devices are using UDP Multicast and find out of they can be configured to use UDP Unicast instead. If not, I would try to figure out how to configure the network to use IGMP Snooping to keep the UDP traffic from flooding the network.

Right give me five minutes while I google half of that terminology

Shall look into it and let you know. Thanks for the quick responses!

performing cyclic I/O control of remote I/O chassis and other devices using UDP Multicast.

Click to expand...

Look for ControlLogix chassis that have a 1756-ENBT module but no CPU, or for FLEX I/O or drives or other I/O style devices connected to the network.

To do this right requires some knowledge of networking principles and network analysis. If you have some "IT guys" onsite who are comfortable running software tools like Wireshark to show you the traffic on the network, that would be a great step forward.

If all you’re doing is trying to access the network wirelessly, I wouldn’t use a wireless router. I’d use an Access Point with a single LAN connection into the switch. Anytime you have a wireless router it needs to “play nice” with other switches and routers in the network and while it can be made to work, (as you’ve seen) it sometimes takes a pretty good understanding of IT principles. An Access Point will simply provide a wireless point of entry into the network. With that said, you also need to make sure that IT is OK with this. Adding an Access Point often gets IT folks panties in a bunch.
P.S. This doesn’t take away from what Ken was talking about. You should still have a good managed switch that can handle the type of network traffic it will be exposed to.

Firejo that's exactly what I'm using, a WAP54G access point with the one connection in which is why im a tad confused it wont work on the full network but in effect a quarter of it. The unicast/multicast is ringing true however