Nortel Networks WEB OS 212777 - Manual (Page 171)

Web OS 10.0 Application Guide
Chapter 7: Filtering n 171
212777-A, February 2002
n
proto : protocol number or name as shown in Table 7-1
n
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.
n
dport : TCP/UDP application or destination port as shown in Table 7-2 , or destination port
range (such as 31000-33000)
n
invert : reverse the filter logic in order to activate the filter whenever the specified condi-
tions are not met.
n
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 to
your main server except from a trusted IP address. Another filter could warn you if FTP access
is attempted from a specific IP address. Another filter could redirect all incoming e-mail traffic
to a server where it can be analyzed for spam. The options are nearly endless.
Table 7-1 Well-Known Protocol Types
Number Protocol Name
1
2
6
17
89
112 icmp
igmp
tcp
udp
ospf
vrrp
Table 7-2 Well-Known Application Ports
Number TCP/UDP
Application Number TCP/UDP
Application Number TCP/UDP
Application
20
21
22
23
25
37
42
43
53
69
70 ftp-data
ftp
ssh
telnet
smtp
time
name
whois
domain
tftp
gopher 79
80
109
110
111
119
123
143
144
161
162 finger
http
pop2
pop3
sunrpc
nntp
ntp
imap
news
snmp
snmptrap 179
194
220
389
443
520
554
1645, 1812
1813
1985 bgp
irc
imap3
ldap
https
rip
rtsp
Radius
Radius Accounting
hsrp