I've got a client on Comcast Bus. Class internet with comcast VOIP phones and their internet has been dropping every couple weeks.
The problems started when they moved into a new office and made the switch to Comcast. Before they were on Surewest & it was rock-solid.
Soon as they move into this new office, the internet keeps dropping about every 2/3 weeks or so. A power cycle of the comcast modem resolves the issue. The Sonicwall is the same they've had for years.
The last time it happened earlier this week, I said the hell with it & had Comcast replace the modem. Now the issue is significantly worse & keeps cutting out every few hours.
Comcast is insistent there is nothing wrong on their end and also said that if it truly was their connection dropping, the clients VOIP phones would stop working too.
I'm trying to rule out any problems on the LAN. We did not make any configuration changes to the server that I'm aware of - they've been running exchange for a while.
Here's their network setup:
- Comcast modem plugs into a Sonicwall TZ100.
- They have Cisco phone boxes and a Cisco managed switch.
- SBS 2011, DC running Exchange and file/print sharing. It handles DHCP.
Here's what I've tried/checked:
- Comcast replaced modem, problem got worse.
- Firewall OFF on Comcast modem.
- DHCP Disabled on Sonicwall: Check.
- DHCP disabled on Netgear router/WAP: Check.
- DHCP disabled on NAS: check. (They have a Netgear NAS for backup that can distribute DHCP)
- DHCP IS enabled on the Comcast, but different scope. Their LAN is 10.10.0.X and the Comcast is 10.1.10.X. I believe Comcast does not recommend disabling DHCP on their modems, but I'm thinking of changing it to 192.168.16.X
- Replaced Cat6 cable running from modem into Sonicwall WAN port with a new Cat6 cable.
- Checked & traced all physical cables, ensured all cables look good/healthy & are fully seated.
- Checked that all power adapters are fully seated in wall & devices - the modem power is a large wall wart that is connected upside-down - doesn't seem super stable.
However the cord that is currently installed & connected to the modem is zip-tied together with the power to the phone box - is it possible the power supply is bad & the comcast guy re-used the same one with the second modem?
I looked in the event logs on the DC & found the following:
Event 1050, DHCP Server - the DHCP/BINL service on the local machine encountered a network error. The error was: 0x2
Warning 1056 "the DHCP service has detected that it is running on a DC and has no credentials configured for use with Dynamic DNS registrations initiated by the DHCP service."
WINS Errors 4224 and 4291
Could any of those errors be causing the problem?
It just seems strange that this all started with the new office/new internet and also became WORSE after a new modem was installed....should we go third times the charm & have comcast replace the modem yet again??
The problems started when they moved into a new office and made the switch to Comcast. Before they were on Surewest & it was rock-solid.
Soon as they move into this new office, the internet keeps dropping about every 2/3 weeks or so. A power cycle of the comcast modem resolves the issue. The Sonicwall is the same they've had for years.
The last time it happened earlier this week, I said the hell with it & had Comcast replace the modem. Now the issue is significantly worse & keeps cutting out every few hours.
Comcast is insistent there is nothing wrong on their end and also said that if it truly was their connection dropping, the clients VOIP phones would stop working too.
I'm trying to rule out any problems on the LAN. We did not make any configuration changes to the server that I'm aware of - they've been running exchange for a while.
Here's their network setup:
- Comcast modem plugs into a Sonicwall TZ100.
- They have Cisco phone boxes and a Cisco managed switch.
- SBS 2011, DC running Exchange and file/print sharing. It handles DHCP.
Here's what I've tried/checked:
- Comcast replaced modem, problem got worse.
- Firewall OFF on Comcast modem.
- DHCP Disabled on Sonicwall: Check.
- DHCP disabled on Netgear router/WAP: Check.
- DHCP disabled on NAS: check. (They have a Netgear NAS for backup that can distribute DHCP)
- DHCP IS enabled on the Comcast, but different scope. Their LAN is 10.10.0.X and the Comcast is 10.1.10.X. I believe Comcast does not recommend disabling DHCP on their modems, but I'm thinking of changing it to 192.168.16.X
- Replaced Cat6 cable running from modem into Sonicwall WAN port with a new Cat6 cable.
- Checked & traced all physical cables, ensured all cables look good/healthy & are fully seated.
- Checked that all power adapters are fully seated in wall & devices - the modem power is a large wall wart that is connected upside-down - doesn't seem super stable.
However the cord that is currently installed & connected to the modem is zip-tied together with the power to the phone box - is it possible the power supply is bad & the comcast guy re-used the same one with the second modem?
I looked in the event logs on the DC & found the following:
Event 1050, DHCP Server - the DHCP/BINL service on the local machine encountered a network error. The error was: 0x2
Warning 1056 "the DHCP service has detected that it is running on a DC and has no credentials configured for use with Dynamic DNS registrations initiated by the DHCP service."
WINS Errors 4224 and 4291
Could any of those errors be causing the problem?
It just seems strange that this all started with the new office/new internet and also became WORSE after a new modem was installed....should we go third times the charm & have comcast replace the modem yet again??