Envisalink 3 does not recover after network failure

[cinergi]

Hello,

My EnvisaLink 3 has been working well since I installed it in my DSC PC1550 panel 6 months ago. Today I had a power failure during which my LAN went down because the duration of the power failure exceeded my UPS capacity. The alarm panel remained up due to its internal battery.

The last event registered on my EnvisaLink portal and e-mail notification is the network supervision failure when the network connection was lost. However, when the connection was restored, the EnvisaLink apparently did not recover; the portal still shows it as Offline 8 hours later, and I can't even ping its IP (which is reserved via DHCP).

The EnvisaLink is connected to a switch which is connected to my main router (acting as DHCP server), and I'm guessing what happened is the EnvisaLink requested an IP address as soon as the switch port came up, before the router had finished booting. When it didn't receive a DHCP reply it apparently just gave up, leaving it with no IP address and thus unable to communicate (maybe...) I haven't tried unplugging and reconnecting it to the switch yet because I want to see if it eventually recovers by itself (e.g. after 24 hours).

Is this a known issue with the EnvisaLink following a network disconnection?

Thanks
cinergi

[GrandWizard]

No, the Envisalink will try forever to get an IP address from DHCP. What is the state of your LEDs? that will tell you if the module has an IP or not.

It might be your switch. I've heard of cases where the switch "forgets" that the Envisalink is on a leg and therefore doesn't route any traffic to it. It could also be the integrated switch within the router. This is common problem when switches that are cascaded, especially if the downstream switch is large (many ports).

[cinergi]

Thanks, I haven't opened my alarm panel yet to check the LEDs but I can see through the small holes in the chassis that there's at least 1 red blinking LED on the EnvisaLink, as is normal. It's still not working this morning. I will try resetting my switch tonight.

cinergi

[cinergi]

Just wanted to add that my EV-3 came back online today exactly 24 hours after network connectivity was restored yesterday. It is now working fine and connected to the portal! Whatever the problem was, it seems related to a 24-hour timer from the time the network was restored. The only such timer I'm aware of is the DHCP lease timer, which would support my theory in my earlier post. However, if the EV-3 does indeed keep trying forever to get an IP address via DHCP as indicated by GrandWizard, then my theory is wrong - the EV-3 would have recovered earlier.

In conclusion, I am still not sure what caused the issue I'll have to do some further investigation by running a Wireshark packet capture on the EV-3's assigned IP address to see exactly what's happening when the network connection is interrupted and restored, when I have some spare time...

Best Regards,
cinergi

[GrandWizard]

I think your lease timer theory is correct. The router may have given the Envisalink a bogus IP address on startup and the Envisalink kept it until the timer ran out.

Remember that a computer running wireshark will only see broadcast packets, not packets between the router and the Envisalink. The only way around this is to put the Envisalink and the packet capture computer on the same HUB, not a switch.

[cinergi]

My router is actually the packet capture device; it runs Linux-based DD-WRT firmware. I meant to say tcpdump in my last post, not Wireshark. The router is able to see any traffic between the EnvisaLink and the Internet.

cinergi

[DaveSin]

Interesting! I have a DD-DWRT Router (WRT54G-TM) and the EnvisaLink 3 is connected to a 8-Port Switch, which in turn is connected to the Router. My setup has experienced multiple Power failures and quickly recovered within minutes of power restoration. My Envisalink is set to a Static IP Address and I also have that IP address reserved under "SERVICES" with no specified Lease Time entered.

Can you assign a Static IP Address to the EnvisaLink 3 to see if it recovers within minutes are power is restored?

My router is actually the packet capture device; it runs Linux-based DD-WRT firmware. I meant to say tcpdump in my last post, not Wireshark. The router is able to see any traffic between the EnvisaLink and the Internet.

cinergi

[cinergi]

Thanks, that sounds very similar to my setup except my DD-WRT router is a Cisco/Linksys E3000 and my switch is only 5 ports. The static vs. dynamic IP address could explain why your EnvisaLink recovered quickly while mine did not. I will try this.

cinergi