•‘TFTP’: The Eicon 1530 can function as a TFTP server to support uploading and downloading of configuration files. If you filter TFTP traffic, you will not be able to use this feature.
•‘DNS’: Domain name system. Filtering DNS datagrams can cause disruptions in the ability to access remote sites.
The following options are also available: NFS/RPC, News, Time (NTP), BOOTP, SNMP, ICMP, Ping (ICMP), Ping Reply, ICMP Redir. For a description of these protocols, consult the appropriate RFC at the site http://www.faqs.org/.
Warning: Be Careful when Creating Filters
The ability to create filters is a very powerful tool. However, it is quite easy to define a filter that would essentially bar all incoming and outgoing data, including access to the Eicon 1530’s web or command line interface to change settings.
Please read Default Filters on page 58 before experimenting with filters.
If you find you have accidentally filtered yourself out of access to the Eicon 1530, you must reset the box to factory defaults by holding down the reset button for 15 seconds. However, you will lose all configuration information. As a precaution, back up your configuration before using filters.
Default Filters
When a profile has no filters defined, a default filter is automatically supplied by the Eicon 1530, as shown below.
Default filter
The default filter forwards all packets from anywhere. Essentially, all traffic is allowed through unimpeded. The default filter is always the last filter in the stack and cannot be edited.
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