kernelconfig_penguin
default or selected kernelversion does not have config value CONFIG_ATM_BR2684_IPFILTER.
Result is shown for kernelversion 5.9.9

Per-VC IP filter kludge

configname: CONFIG_ATM_BR2684_IPFILTER

Linux Kernel Configuration
└─> Networking support
└─> Networking options
└─> Per-VC IP filter kludge

This is an experimental mechanism for users who need to terminate a
large number of IP-only vcc's. Do not enable this unless you are sure
you know what you are doing.