Moreover, in the router's 'Connected Devices Summary', the same MAC was showing up, but this time with an IP (10.0.0.74) on the LAN! What happened next puzzled us: in the router's 'Preassigned DHCP IP Addresses'-list an unknown MAC, 00:11:e6:de:ad:07 (00:11:e6 belongs to Scientific Atlanta, part of Cisco), was occupying 192.168.0.201. We also reserved 192.168.0.201 for the MAC of the NIC facing the modem. We proceeded to activate the DHCP with starting address 192.168.0.201 and with a range of 1. Although our LAN has static addresses and DNS configurations on each NIC are set to the ISP's recommended DNSs, they told us that activating the DHCP in the router 'sometimes helps'. The NIC on the firewall facing the WAN was set to 192.168.0.201.

We also had the DHCP in the modem was switched off. They also set up monitoring of the WAN segment that the modem is on and that ran for several days without finding any problems. They found no problems, neither with the modem itself nor the signal strength or the cable. The ISP did a checkup of the router and the connection to the rest of the WAN. Certain services like Skype are not affected. This behavior seem to occur at random and during irregular time periods (1-30 minutes approx.). The connection started to get slower and sometimes we do not have a connection at all. The router's WIFI has been disabled.Ī few days ago we noticed problems when fetching mail or browsing. No other equipment is connected to the router. Our LAN (10.0.0.1/24) is beyond the firewall.

The router is connected to a firewall (an Ubuntu-box running iptables and Wireshark). We have a Cisco EPC3928AD EuroDocsis 3.0 2-PORT Voice Gateway from our ISP.

Hack cisco setup box