iptstate - A top-like display of IP Tables state table entries
iptstate displays information held in the IP Tables state table in real-time in a top-like format. Output can be sorted by any field, or any field reversed. Users can choose to have the output only print once and exit, rather than the top-like system. Refresh rate is configurable, IPs can be resolved to names, output can be formatted, the display can be filtered, and color coding are among some of the many features.
|Toggle color-code by protocol|
|Toggle display of bytes/packets counters|
|-d, --dst-filter IP|
|Only show states with a destination of IP Note, that this must be an IP, hostname matching is not yet supported.|
|-D --dstpt-filter port|
|Only show states with a destination port of port|
|Show help message|
|Show hostnames instead of IP addresses. Enabling this will also enable -L to prevent an ever-growing number of DNS requests.|
|Mark truncated hostnames with a ’+’|
|Toggle dynamic formatting|
|Skip outgoing DNS lookup states|
|Filter states on loopback|
|No scrolling (don’t use a "pad"). See SCROLLING AND PADS for more information.|
|Reverse sort order|
|-R, --rate seconds|
|Refresh rate, followed by rate in seconds. Note that this is for statetop mode, and not applicable for single-run mode (--single).|
|Single run (no curses)|
|-b, --sort column|
|This determines what column to sort by. Options:
S Source Port
d Destination IP (or Name)
D Destination Port
To sort by Source IP (or Name), don’t use -b. Sorting by bytes/packets is only available for kernels that support it, and only when compiled against libnetfilter_conntrack (the default).
|-s, --src-filter IP|
|Only show states with a source of IP. Note, that this must be an IP, hostname matching is not yet supported.|
|-S, --srcpt-filter port|
|Only show states with a source port of port|
|Toggle display of totals|
As of version 2.0, all command-line options are now available interactively using the same key as the short-option. For example, --sort is also -b, so while iptstate is running, hitting b will change the sorting to the next column. Similarly, t toggles the display of totals, and so on.
In many cases, iptstate needs to prompt you in order to change something. For example, if you want to set or change the source-ip filter, when you hit s, iptstate will pop up a prompt at the top of the window to ask you what you want to set it to.
There are also extra interactive options: B - change sorting to previous column (opposite of b); q - quit; and x - delete the currently highlighted state from the netfilter conntrack table.
Additionally, the following keys are used to navigate within iptstate:
|Up or j - Move up one line
Down or k - Move down one line
Left or h - Move left one column
Right or l - Move right one column
PageUp or ^u - Move up one page
PageDown or ^d - Move down one page
Home - Go to the top
End - Go to the end
Note that like many UNIX applications, ctrl-G will tell iptstate "nevermind" - it’ll remove the prompt and forget you ever hit s.
In most cases, a blank response means "clear" - clear the source IP filter, for example.
At anytime while iptstate is running, you can hit h to get to the interactive help which will display all the current settings to you as well give you a list of all interactive commands available.
While running, space will immediately update the display. Iptstate should gracefully handle all window resizes, but if it doesn’t, you can force it to re-calculate and re-draw the screen with a ctrl-L.
Note that hitting l to enable hostname resolution while in interactive mode will also enable L to skip all DNS entries (to prevent an ever-growing number of DNS requests).
SCROLLING AND PADS
For almost any user, there is no reason to turn off scrolling. The ability to turn this off - and especially the ability to toggle this interactively - is done more for theoretical completeness than anything else.
|But, nonetheless, here are the details. Typically in a curses application you create a "window." Windows don’t scroll, however. They are, at most, the size of your terminal. Windows provide double-buffering to make refreshing as fast and seemless as possible. However, to enable scrolling, one has to use "pads" instead of windows. Pads can be bigger than the current terminal. Then all necessary data is written to the pad, and "scrolling" becomes a function of just showing the right part of that pad on the screen.
However, pads do not have the double-buffering feature that windows have. Thus, there _might_ be some case where for some user using some very strange machine, having scrolling enabled could cause poor refreshing. Given the nature of the way iptstate uses the screen though, I find this highly unlikely. In addition, the scrolling method uses a little more memory. However, iptstate is not a memory intensive application, so this shouldn’t be a problem even on low-memory systems.
Nonetheless, if this does negatively affect you, the option to turn it off is there.
Anything other than 0 indicates and error. A list of current exit statuses are below:
|1||Bad command-line arguments|
|2||Error communicating with the netfilter subsystem.|
|3||Terminal too narrow|
We don’t support filtering on resolved names, and we don’t support filtering on networks. IPv6 support is new and the dynamic formatting doesn’t yet always handle IPv6 addresses as well as it should.
All bugs should be reported to Phil Dibowitz <phil AT ipom DOT com>. Please see the README and BUGS for more information on bug reports. Please read the WISHLIST before sending in features you hope to see.
iptstate does a lot of work to try to fit everything on the screen in an easy-to-read way. However, in some cases, hostnames may need to be truncated (in lookup mode). Similarly, IPv6 addresses may need to be truncated. The truncation of names happens from the right for source because you most likely know your own domain name, and from the left for destination because knowing your users are connection to "mail.a." doesn’t help much. However, for addresses, this is reversed.
iptstate does not automatically handle window-resizes while in the interactive help screen. If you do resize while in this window, you should return to the main window, hit ctrl-L to re-calculate and re-draw the screen, and then, if you choose, return to the interactive help.
iptstate currently uses libnetfilter_conntrack to access the netfilter connection state table. However, older versions read out of /proc/net/ip_conntrack, and the current version can still be compiled to do this. This deprecated method can be racy on SMP systems, and can hurt performance on very heavily loaded firewalls. This deprecated method should be avoided - support will be removed in future versions.
iptstate was written by Phil Dibowitz <phil AT ipom DOT com>