FlowMonitor requires a SQL database backend. Initial revisions were written with a filesystem backend, but this proved problematic with the usage our campus was seeing (approximately 10k unique IPs in a 5 minute sample, approx 120k total IPs). We use Oracle, but any DBD module that works with Perl should also work.
$ flowscan FlowMonitor
or in flowscan.cf: ReportClasses FlowMonitor
# Subnet for main campus Subnet 18.104.22.168/16
Add as many of these as is necessary. FlowMonitor assumes that flows will either have a source address in a one of the declared Subnets, or a destination address there, but not both. (Ie, FlowMonitor should be used on flows collcted from a boundary router whos traffic we are interested in policing). FlowMonitor will keep records on the usage of all IPs it sees in flow records whose source or destination IP is in a Subnet statement.
# Only interested in traffic from nyser-gw Router 22.214.171.124
You need to put a Router statement in you FlorMonitor.cf for every exporter through which you wish to police traffic. Note if you have more than one Router, your Policy statement will refer to total bandwidth through all listed Routers. Per-Router policies and violation files may be in a forthcoming release, but for now, FlowMonitor enforces a single policy over one or more exporters.
# Policy is limit upload to 100Kb/sec Policy Outbound 8640000000 86400
The first argument determines which bytes we count for an individual IP. Allowed values for this argument are Inbound, Outbound, or Both. The Inbound policy only counts flows whose destination address is contained in a range defined in a Subnet statement. The Outbound policy only counts flows whose source address is defined in a Subnet statement. The Both policy totals bytes when either the source or the destination address is in a Subnet statement.
The second argument is the number of bytes allowed per IP. The third is the number of seconds over which they are allowed to use those bytes. The above policy says that over 86400 seconds (1 day), an individual IP address is allowed to use 8,640,000,000 bytes (8.6Gb/day, roughly 100Kb/second).
create table iplogs ( ipaddr
number(16), starttime date, constraint iplogs_ct
making sure that the user FlowMonitor will be running as has permissions to insert, delete and modify from this table.
# Store records in oracle database acisora1 DBName Oracle acisora1
The first parameter should be the name of the DBI module perl should use to contact the database whose name is the second parameter. Currently, we do not support a username and password to bind with.
# People at 50% over policy get logged to 50percenters Violators 50 /var/log/50percenters # People at 100% over policy get logged to 100percenters Violators 100 /var/log/100percenters # People at 200% or more over policy go to losers Violaters 200 /var/log/losers
Each IP will only appear in 1 file, so someone at 100% over the policy (in the above example) will *not* appear in the 50percenters file, only the 100percenters file. Anyone whose percentage of usage is higher than the highest percentage in a Violators statement gets logged in the highest percentage file.
Note that Carry-Forward will only carry one intervals worth of quota ahead, so an IP will never start a new interval with more than 1 intervals quota. To continue the above example, if 126.96.36.199 finished an hour with 300 megabytes of usage, it will still only begin the next hour with 100 megabytes of usage, as that is one intervals quota. This way of implementing Carry-Forward was chosen because in an environment where IPs are assigned dynamically, or more than one person can use a given IP (ie, a computer lab), we did not want to unduly penalize a given IP for more than 2 quota intervals. Note that if a given host is continually using more than 2 times its quota every interval, it will always be in violation.
# Ignore our webserver Ignore 10.0.0.1/32 # Ignore machine room hosts Ignore 10.0.1.0/24
You may have as many Ignore statements as you wish.
# Ignores to ignorelist.txt IgnoreList /var/www/html/ignorelist.txt
This file is truncated before writing; it is not a log file, it is a list of the current ignores. If you do not include this statement, no list will be produced.
# Log bad people to /var/log/mon-history Logfile /var/log/mon-history
If you have no Logfile statement, FlowMonitor will not log when people enter Violator groups.
Database handling is pretty messy.
Carry-Forward should be more configurable.