Cable Modems and AMX
ericmedley
Posts: 4,177
I'm putting this out to see if anyone has any insight to an annoying problem we're having in general.
Our AMX systems often have problems with connectivity. It manifests itself in loss of connectivity with touch panel(s). What seems to be the issue is Cable Modems here in our area. The places where we have trouble use Comcast.
DSL or T1 lines never exhibit the problems.
What seems to be the problem occurs around the time the Cable Modem is forced to change its WAN IP address. As you may know Cable internet is more or less an ad-hoc network that can change subnets depending upon bandwidth needs and whatnot. So, the WAN IP address of a given house might be 64.xxx.yyy.zzz one week. but it might be 74.xxx.yyy.zzz the next. Some of our clients have had the same WAN IP for 2 years. Others seem to change almost weekly.
the AMX problems occur right after a WAN IP address change. Panels will loose their connection to the master. They still have good wirelesss access point connections and good internet connections on wired panels. The Netlinx master can see the outside world. Most computers in the house can see the outside world. Some don't.
However, rebooting the panel does not fix the TP connection problem. The fix is either rebooting the Netlinx master and if that fails, then resetting the enitire Network. (Modem/router/Switches/WAPs then all the IP devices.) Once this is done, the system will work very reliably until the next WAN IP change.
The master is set to a static IP. The TPs are randomly Static or DHCP (this for testing to find a fix.) The TP settings don't seem to correlate to the problem in any way. In some cases, there will be some TPs that are set to static and some to DHCP that fall away. Changing them to the other setting and rebooting them doesn't fix the problem. In addition, there will be many TPs in the same system that work just fine.
Has anyone had any experience with this or any helpful hints. Comcast has been no help at all.
Thanks
e
Our AMX systems often have problems with connectivity. It manifests itself in loss of connectivity with touch panel(s). What seems to be the issue is Cable Modems here in our area. The places where we have trouble use Comcast.
DSL or T1 lines never exhibit the problems.
What seems to be the problem occurs around the time the Cable Modem is forced to change its WAN IP address. As you may know Cable internet is more or less an ad-hoc network that can change subnets depending upon bandwidth needs and whatnot. So, the WAN IP address of a given house might be 64.xxx.yyy.zzz one week. but it might be 74.xxx.yyy.zzz the next. Some of our clients have had the same WAN IP for 2 years. Others seem to change almost weekly.
the AMX problems occur right after a WAN IP address change. Panels will loose their connection to the master. They still have good wirelesss access point connections and good internet connections on wired panels. The Netlinx master can see the outside world. Most computers in the house can see the outside world. Some don't.
However, rebooting the panel does not fix the TP connection problem. The fix is either rebooting the Netlinx master and if that fails, then resetting the enitire Network. (Modem/router/Switches/WAPs then all the IP devices.) Once this is done, the system will work very reliably until the next WAN IP change.
The master is set to a static IP. The TPs are randomly Static or DHCP (this for testing to find a fix.) The TP settings don't seem to correlate to the problem in any way. In some cases, there will be some TPs that are set to static and some to DHCP that fall away. Changing them to the other setting and rebooting them doesn't fix the problem. In addition, there will be many TPs in the same system that work just fine.
Has anyone had any experience with this or any helpful hints. Comcast has been no help at all.
Thanks
e
0
Comments
Is the DNS changing?
Are you running any applications on the master that need to go out to the internet?
What type of router are you using?
What type of WAPs are you using?
And last but not least....
Did you really think Comcast could or would help you?
To me it sounds like a faulty network period. The outside world has nothing to do with the inside world; getting a different WAN IP can't possibly mess up local network devices and their connection to other devices within the network.
The ones that are set up DHCP, I would suggest you change them to static - DHCP = bad. Although some will say, "we've never had problems with DHCP" - and I think they're lucky. How many times have you gotten on your computer and it says, "IP conflict" ? I've had it happen quite a few times, and it's all because of DHCP.
Are your static IPs below or above the range of DHCP? Meaning, if DHCP starts at x.x.x.100, and the addresses aren't x.x.x.102 - x.x.x.106 are they?
I'm sure you've got all that set up correctly, and you've been setting them up correctly - but I just don't think a cable modem could possibly disrupt a local network. Stranger stuff has happened.
WAPs - Cisco 1100s / Linksys, one case of 2-Wire (we quit using the AMX ones a while back.)
All our static stuff lives from 192.168.XXX.10~99
DHCP is ... 100~200
Client Static IPs are from ...201~239
WAPs are ...240~249
that's the only logical explaination to me as well. In each of these cases there are 4 entities involved with setting up the network. Us, and three networking companies. All are reputable and all have set up other networks that work very reliably.
I also agree that logic would dictate that Comcast is not at fault. It's just that the only common thread seems to be the Cable Modem internet and the changing of the WAN IPs. The chaning DNS is traceable to Comcast. If the DNS changes on the modem, the router must be rebooted to aquire the new DNS.
Also, we have heard from Comcast techs that they do block external use of DNS from outside the subnet. Comcast support denies it, but several techs have quietly confirmed it. A lot of DNS servers are doing likewise in the other direction. It's a response to a security threat exploited by the hackers as of late.
thanks for the suggestions. I'll keep monitoring the post.
eric
In our situtation we have two homes with Comcast Internet that do not exhibit any problems at all. One is literally at the edge of the continent and is the last on a long line from Comcast. It has had the same WAN IP, DNS, etc... for over 2 years now. It has been stable and reliable even when the electricity has not.
the other is in the 'danger zone' with the other problem systems geographically. Its WAN IP changes about once a month but the internal network stays solid. When the DNS changes the whole house goes dark. (you can type in web address manually by ip address but www.sitename.com won't work until you update the DNS. However, the AMX system's touch panels stay on solid through the whole episode. It has a mid-level Linksys router. We have the same router in one other house that is one of the worst of the bunch.
This is why I love AXLink...
Everything on the Netlinx master connects by IP address, not www.whatever.com The i!-Weather I cannot speak for. But, it still works when things are not well. So, I assume it's also IP.
Also, how are things connected? For example, is the master generally plugged into the router and all of the access points/touch panels are connected to a larger switch? Instead of rebooting, have you tried just unplugging the network cable and moving it to a different port?
Just some thoughts,
Jeff
Yes, I set it to the router.
Careful with the Sonicwall. On the units we use, they do not forward DNS requests.
Jeff
Once we setup the ports for all of our devices to the correct speed (100mbit full-duplex for most) the system was much more stable.
I am also curious about why you need all those separate routers and the network topology for how the system is connected (Modem -> cisco router -> linksys router -> AMX system switch etc.)
Our network topology is not as you describe. I'm not sure if I mentioned it at all.
It's usually:
Cable Modem -> some router -> switch (for the whole house ~ 24-48 ports) -> The stuff.