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New Member

1721 Series - Erratic Connections To The Internet


Cisco 1721 Series Router

2 x 1-DSU-T1 V2 WICs

Netgear Firewall connected to the LAN of the router.


One minute we can access outside sites and people outside can access ours, the next minute or few we can't access any outside sites nor can anyone access ours. Its like we're not connected at all.

Cause: Everything is fine until we attach more systems to the LAN than we currently have.

Solution: Has been to power down every server on our DMZ, reset the Router, Firewall, DMZ switch and disconnect the LAN from the Firewall. Then bring each system on the DMZ back up one by one, then reconnect the LAN to the Firewall.

Obviously I would think this a problem with anything BUT the Router. But there was one odd occurance the first time this happened. On the router, in BOTH the WIC0 and WIC1 slots, the lights for the CH1 were lit up orange/yellow. It is my understanding that the CH1 lights are only used when there are 2-port WICs installed. But the 1-DSU-T1 V2 is a 1 port WIC. If there is one thing I can take from this conservsation, its why would those lights be lit up at all, let alone orange/yellow. The CH0 lights have been green across the board.

Ever since we reset the Router the first time, we have not had these lights come up, but we still get the situation where the entire network drops access to the outside internet. Any suggestions on the odd cause/effect would help as well. Thank you.

New Member

Re: 1721 Series - Erratic Connections To The Internet

How many systems do you have right now attached to the LAN segment of your router? send me the output of the debug cmd which indicates the background process of the router. It will be a little easy for me to trace that output message to identify the reason for this malfunctioning.

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