On latest master (I am testing 9febbcdc), ping from cli seems to ignore icmp replies which get dropped:

1. create veth & assign Linux host IP
   ~# sudo ip link add dev vm1 type veth peer name vm2
   ~# sudo ifconfig vm2 1.1.1.2/24 up
2. run VPP, disabling rdma to be sure
   ~# $PWD/build-root/install-vpp_debug-native/vpp/bin/vpp "unix { interactive }

   plugins

   Unknown macro: { plugin rdma_plugin.so { disable } }

   "
   DBGvpp# create host-interface name vm1
   DBGvpp# set int ip addr host-vm1 1.1.1.1/24
   DBGvpp# set int st host-vm1 up
   DBGvpp# clear trace
   DBGvpp# trace add af-packet-input 10
   DBGvpp# ping 1.1.1.2
   Statistics: 5 sent, 0 received, 100% packet loss
   DBGvpp# sh tr

   • • • • • • • • • • • • • • • • • • Start of thread 0 vpp_main -------------------
                                       Packet 1

00:00:01:043605: af-packet-input
af_packet: hw_if_index 1 next-index 4
tpacket2_hdr:
status 0x20000001 len 42 snaplen 42 mac 66 net 80
sec 0x5ce6a84c nsec 0x28be2a1f vlan 0 vlan_tpid 0
00:00:01:044117: ethernet-input
ARP: f2:dc:63:9b:18:c2 -> 02:fe:61:ef:48:39
00:00:01:044171: arp-input
reply, type ethernet/IP4, address size 6/4
f2:dc:63:9b:18:c2/1.1.1.2 -> 02:fe:61:ef:48:39/1.1.1.1
00:00:01:044969: error-drop
rx:host-vm1
00:00:01:044980: drop
arp-input: ARP request IP4 source address learned

Packet 2

00:00:02:050854: af-packet-input
af_packet: hw_if_index 1 next-index 4
tpacket2_hdr:
status 0x20000001 len 110 snaplen 110 mac 66 net 80
sec 0x5ce6a84d nsec 0x294bbace vlan 0 vlan_tpid 0
00:00:02:051362: ethernet-input
IP4: f2:dc:63:9b:18:c2 -> 02:fe:61:ef:48:39
00:00:02:051380: ip4-input
ICMP: 1.1.1.2 -> 1.1.1.1
tos 0x00, ttl 64, length 96, checksum 0xd847
fragment id 0x9e51
ICMP echo_reply checksum 0x8665
00:00:02:051415: ip4-lookup
fib 0 dpo-idx 5 flow hash: 0x00000000
ICMP: 1.1.1.2 -> 1.1.1.1
tos 0x00, ttl 64, length 96, checksum 0xd847
fragment id 0x9e51
ICMP echo_reply checksum 0x8665
00:00:02:051430: ip4-local
ICMP: 1.1.1.2 -> 1.1.1.1
tos 0x00, ttl 64, length 96, checksum 0xd847
fragment id 0x9e51
ICMP echo_reply checksum 0x8665
00:00:02:051437: ip4-icmp-input
ICMP: 1.1.1.2 -> 1.1.1.1
tos 0x00, ttl 64, length 96, checksum 0xd847
fragment id 0x9e51
ICMP echo_reply checksum 0x8665
00:00:02:051444: vpe-icmp4-oam
OAM: rx from address 1.1.1.2, target index -1
00:00:02:051451: error-drop
rx:host-vm1
00:00:02:051458: drop
vpe-icmp4-oam: icmp4 replies dropped (no registration)