If you have IP Phones you should use FXO. FXS is for normal phones to be converted to IP Phones.

After you connect the cisco 871 to the cable modem, call the ISP and tell them to clear cable host or to reset the modem and clear the arp's.

Please put some screenshots. Those spikes are only in the day where you start mrtg or all the time ?You can put something like this in mrtg.cfg to each interfaceMaxBytes[ubr10k_2]: 12500000

try to put thissnmp-server enable traps syslog

With syslog-ngIn syslog-ng.conf you put something like thisdestination ra1 { file("/logging/sw/ra1"); };filter f_ra1 { host(ip_ra1); };log { source(net); filter(f_ra1); destination(ra1); };and on cisco switch you put smth like this#s...