ping -Mdo -s
If it works:
$ ping -Mdo -s 8001 10.0.20.26
PING 10.0.20.26 (10.0.20.26) 8001(8029) bytes of data.
8009 bytes from 10.0.20.26: icmp_req=1 ttl=64 time=0.450 ms
8009 bytes from 10.0.20.26: icmp_req=2 ttl=64 time=0.468 ms (DUP!)
8009 bytes from 10.0.20.26: icmp_req=3 ttl=64 time=0.447 ms
If it doesnt:
$ ping -Mdo -s 2001 195.10.34.51 -c3
PING 195.10.34.51 (195.10.34.51) 2001(2029) bytes of data.
From XX.XX.XX.XX icmp_seq=1 Frag needed and DF set (mtu = 1500)
From XX.XX.XX.XX icmp_seq=1 Frag needed and DF set (mtu = 1500)
From XX.XX.XX.XX icmp_seq=1 Frag needed and DF set (mtu = 1500)