Hello,
I am a network administrator working in Virginia and I am seeing a small number of packets of IP addresses that don’t exist on our network hitting the inside of our firewall where it is then stopped. Both the source and destination addresses are from companies that provide Cable or DSL internet access. We have dial-up access for employees. There are ACL’s on the dial-up Cisco routers that only allow only allow traffic that is owned by the network through. Any suggestions as to whythis is happening?
Some ideas have been:
1) Someone is bringing in a comp with the wrong config and trying to put it on the network (seriously doubtful though)
2) Someone is dialing in with a phone modem, but also has NIC card with cable internet access. Somewhere when dialed in, the computer uses the NIC card’s IP address and tries to send data over the phone line connection? (this is what we are leaning towards but can’t prove it)
Let me know if this is possible or if you have any other suggestions.
Thanks,
Jeff