Defines starting with `m' in netinet

• MAX_IPOPTLEN netinet/ip_var.h:97
• MAX_TCPOPTLEN netinet/tcp_output.c:66
• MAXTTL netinet/ip.h:163
• MAXVIFS netinet/ip_mroute.h:68
• MRTHASHSIZ netinet/ip_mroute.h:148