tcpdump -i vlan99 -vvvvn 'icmp[0] = 3 and host 10.99.154.254'
11:45:59.318406 00:08:a2:0d:00:70 > f4:f5:d8:d2:f2:4c, ethertype IPv4 (0x0800), length 126: (tos 0xc0, ttl 64, id 21013, offset 0, flags [none], proto ICMP (1), length 112)
    10.99.0.2 > 10.99.154.254: ICMP host 8.8.8.8 unreachable, length 92
    (tos 0x0, ttl 63, id 0, offset 0, flags [DF], proto ICMP (1), length 84)
    10.99.154.254 > 8.8.8.8: ICMP echo request, id 1044, seq 1, length 64

Feb 21 11:45:59 ganymede kernel: IPv4: martian source 10.99.154.254 from 8.8.8.8, on dev eth-ext1
Feb 21 11:45:59 ganymede kernel: ll header: 00000000: 00 08 a2 0d 00 70 f4 f5 d8 d2 f2 4c 08 00