IP Configuration Configuring IP
page 24-28 OmniSwitch AOS Release 6 Network Configuration Guide September 2009
To verify the number of attacks detected for configured ARP poison restricted addresses, use the show ip
dos arp-poison command. For more information about this command, see the OmniSwitch CLI Reference
Guide.
Enabling/Disabling IP Services
When a switch initially boots up, all supported TCP/UDP well-known service ports are enabled (open).
Although these ports provide access for essential switch management services, such as telnet, ftp, snmp,
etc., they also are vulnerable to DoS attacks. It is possible to scan open service ports and launch such
attacks based on well-known port information.
The ip service command allows you to selectively disable (close) TCP/UDP well-known service ports and
enable them when necessary. This command only operates on TCP/UDP ports that are opened by default.
It has no effect on ports that are opened by loading applications, such as RIP and BGP.
In addition, the ip service command allows you to designate which port to enable or disable by specifying
the name of a service or the well-known port number associated with that service. For example, both of the
following commands disable the telnet service:
-> no ip service telnet
-> no ip service port 23
Note that specifying a port number requires the use of the optional port keyword.
To enable or disable more than one service in a single command line, enter each service name separated by
a space. For example, the following command enables the telnet, ftp, and snmp service ports:
-> ip service telnet ftp snmp
The following table lists ip service command options for specifying TCP/UDP services and also includes
the well-known port number associated with each service:
service port
ftp 21
ssh 22
telnet 23
http 80
secure-http 443
avlan-http 260
avlan-secure-http 261
avlan-telnet 259
udp-relay 67
network-time 123
snmp 161
proprietary 1024
proprietary 1025
To Next Page
Loading...
