Bypassing advanced device profiling with DHCP packet manipulation
Device profiling may at first sound abstract to some readers, so let me first explain what this is. Device profiling is any mechanism that helps you determine the fingerprint of your device. The fingerprint may be any set of determinations whether your device is running Linux or Windows operating system, what its FQDN is, what version of particular software (antivirus etc.) it runs, maybe even contact details of the system administrator responsible for administering it. This fingerprint can be extracted from various application protocols that the device is using to communicate with the networked resources - it may be using SNMP to allow various diagnostic data about its interfaces, DNS to identify its own name or to resolve other names, Cisco Discovery Protocol to identify features of neighboring Cisco devices, DHCP to require the IP address, DNS server, default gateway IP address etc. So, where exactly would such a profiler sit and how does the whole thing work in a r...