Fragmented packets won't work without ICMP. Edit: here's a good page about the effects of disabling ICMP: https://www.rimscout.com/why-you-should-not-block-icm

Fragmented packets won't work without ICMP. Edit: here's a good page about the effects of disabling ICMP: https://www.rimscout.com/why-you-should-not-block-icmp/ https://www.rimscout.com/why-you-should-not-block-icmp/ Also there's some blackhole detection or how is it called. However it's OK to block _parts_ of the ICMP protocol for security reasons, like echo and reply.