Probably it can be a wrong value of MTU parameter on interfaces during configuration or someone/something  intentionally send fragmented packets to the interfaces. 

Hi,Try to increase value X in option "ip virtual-reassembly max-reassemblies X" under the specific interface.The range of X varies between 16 an 1024 if I am not mistaken.Hope it helps!

I had the same issue with EVE-NG and GNS3 labs: PCs on both ends could not ping each other, neither neighbor router's gw interface. The solution for me was disabling no ip route-cache  on local router's interface. In your case you should disable it o...