[root@compute11 ~]# tcpdump -i eth2
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes
14:03:47.668695 STP 802.1d, Config, Flags [none], bridge-id 80c8.b8:be:bf:27:22:80.800d, length 42
14:03:47.687639 IP 192.168.2.237 > 192.168.2.236: GREv0, key=0x2, length 106: IP 192.168.1.3 > 192.168.1.2: ICMP echo request, id 26369, seq 13, length 64
14:03:47.688008 IP 192.168.2.236 > 192.168.2.237: GREv0, key=0x2, length 106: IP 192.168.1.2 > 192.168.1.3: ICMP echo reply, id 26369, seq 13, length 64
14:03:48.688855 IP 192.168.2.237 > 192.168.2.236: GREv0, key=0x2, length 106: IP 192.168.1.3 > 192.168.1.2: ICMP echo request, id 26369, seq 14, length 64
14:03:48.689294 IP 192.168.2.236 > 192.168.2.237: GREv0, key=0x2, length 106: IP 192.168.1.2 > 192.168.1.3: ICMP echo reply, id 26369, seq 14, length 64
14:03:49.673357 STP 802.1d, Config, Flags [none], bridge-id 80c8.b8:be:bf:27:22:80.800d, length 42
14:03:49.690040 IP 192.168.2.237 > 192.168.2.236: GREv0, key=0x2, length 106: IP 192.168.1.3 > 192.168.1.2: ICMP echo request, id 26369, seq 15, length 64
14:03:49.690303 IP 192.168.2.236 > 192.168.2.237: GREv0, key=0x2, length 106: IP 192.168.1.2 > 192.168.1.3: ICMP echo reply, id 26369, seq 15, length 64