The below table lists common IP protocols and their well-known numbers.
The authoritave list can be found on the IANA website here
| Protocol Number | Protocol |
| 1 | ICMP |
| 2 | IGMP |
| 6 | TCP |
| 17 | UDP |
| 41 | IPv6 in IP Tunnel |
| 47 | GRE |
| 50 | ESP |
| 51 | AH |
| 88 | EIGRP |
| 89 | OSPF |
| 103 | PIM |
| 112 | VRRP |
| 115 | L2TP |
