Service manual
Cyclades-TS
88
Appendix A - Linux
Installation & Service Manual
The shell script /bin/build_DB_ramdisk creates a 4 Mbyte ramdisk for the TS3000. Use this script as a model to
create customized ramdisks for your environment. Any user-created scripts should be listed in the file /etc/
user_scripts because rc.sysinit executes all shell scripts found there. This avoids changing rc.sysinit itself.
Data buffering can be done in local files or in remote files through NFS. When using remote files, the limitation is
imposed by the remote Server (disk/partition space) and the data is kept in linear (sequential) files in the remote
Server. When using local files, the limitation is imposed by the size of the available ramdisk.
The user may want to have data buffering done in file, syslog or both. For syslog, all.syslog_buffering and
conf.DB_facility are the parameters to be dealt with as seen in the earlier chapters, and syslog-ng.conf file
should be set accordingly (please see Appendix G for syslog-ng configuration file). For file, all.data_buffering is
the parameter to be dealt with as seen in the early chapters.
Packet Filtering using ipchains
(Note: This feature is only available for firmware versions 1.2.x and above)
The Cyclades-TS uses the Linux utility ipchains to filter IP packets entering, leaving and passing through its
interfaces. An ipchains tutorial is beyond the scope of this manual. For more information on ipchains, see the
ipchains man page (not included with the Cyclades-TS) or the howto: http://netfilter.filewatcher.org/ipchains/
HOWTO.html.
The syntax of the ipchains command is:
ipchains -
command
chain
[-s
source
] [-d
destination
] [-p
protocol
] [-j
tar-
get
] [-i
interface
]
where command is one of the following:
A - Add a condition or rule to the end of the chain. Note that the order in which a condition appears in a chain
can modify its application and the first rule added to a chain is processed first, etc.
D - Delete a condition from the chain. The condition must match exactly with the command’s arguments to be
deleted.
R- Replace a condition in the chain.