Web OS 10.0 Application GuideChapter 7: Filtering n 171212777-A, February 2002 proto: protocol number or name as shown in Table 7-1 sport: TCP/UDP application or source port as shown in Table 7-2, or source port range(such as 31000-33000)N OTE – The service number specified on the switch must match the service specified on the server. dport: TCP/UDP application or destination port as shown in Table 7-2, or destination portrange (such as 31000-33000) invert: reverse the filter logic in order to activate the filter whenever the specified condi-tions are not met. Advanced filtering options such as TCP flags (page 197) or ICMP message types (page 201)are also available.Using these filter criteria, you can create a single filter that blocks external Telnet traffic toyour main server except from a trusted IP address. Another filter could warn you if FTP accessis attempted from a specific IP address. Another filter could redirect all incoming e-mail trafficto a server where it can be analyzed for spam. The options are nearly endless.Table 7-1 Well-Known Protocol TypesNumber Protocol Name1261789112icmpigmptcpudpospfvrrpTable 7-2 Well-Known Application PortsNumber TCP/UDPApplicationNumber TCP/UDPApplicationNumber TCP/UDPApplication2021222325374243536970ftp-dataftpsshtelnetsmtptimenamewhoisdomaintftpgopher7980109110111119123143144161162fingerhttppop2pop3sunrpcnntpntpimapnewssnmpsnmptrap1791942203894435205541645, 181218131985bgpircimap3ldaphttpsriprtspRadiusRadius Accountinghsrp
