DD-WRT counting UDP in Conn. Count on LAN page erroneously?

Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Broadcom SoC based Hardware
Author Message




Joined: 01 Jan 1970
Posts:

PostPosted: Tue Oct 07, 2008 17:35    Post subject: DD-WRT counting UDP in Conn. Count on LAN page erroneously? Reply with quote
http://forum.utorrent.com/viewtopic.php?id=47329

Basically, with uTorrent open but idle, DD-WRT's LAN Status page shows 300 connections open. This has something to do with uTorrent's DHT and UDP as I understand it, but uTorrent apparently doesn't have that many sockets open between DHT updates and also I've been informed that UDP apparently shouldn't be counted as a connection anyway and therefore shouldn't be included in the Connection Count.

A possibly better description is at the link above, as well as responses from DWK, a uTorrent forum moderator.

Bug or feature? If so, on who's end? Thoughts, ideas or comments?
Sponsor
switch
DD-WRT Guru


Joined: 30 Apr 2008
Posts: 967
Location: Romania

PostPosted: Tue Oct 07, 2008 18:28    Post subject: Reply with quote
UDP & TCP both have to be translated to pass to the internet from the local LAN. A connection is defined as such an translation. A translation is considered active until closed by either peer or the TCP/UDP specific timeout is up.

So if uTorrent opens 100 connections which are unanswered (remote peer ignores requests - common for custom clients), then idles,you will see those connections until the UDP timeout is up.

The active port count is not an issue on 16MB routers, but might cause issues for smaller routers like the ones with only 8MB RAM. Workaround in that particular case is to limit to a max of 512 active connections and set the timeouts to 90-300s for TCP and 90s for UDP.

It is extremely difficult to track truly active connection count, in case you were trying to use it to gauge activity. For that, you can use SNMP either via SRTG or MRTG to monitor traffic on each interface.

_________________
Q: How do I do ...? A: Read the tutorials or Search forums




Joined: 01 Jan 1970
Posts:

PostPosted: Thu Oct 09, 2008 19:42    Post subject: Reply with quote
I have a WRT300N so I should be fine. Thanks for the informative reply! However..

Lord Alderaan wrote:
For NAT purposes outgoing UDP packets have to be remembered so that return packets are correctly routed (back to your PC). A router still shouldn't call those remembered transactions "connections" though cos that term will confuddle people.

osmosis wrote:
Ah, and it is normal/acceptable for uTorrent to hold ~300 of those "transactions" open between DHT updates then? As I've been saying, this seems high to me.

GTHK wrote:
It's not being held open, your router's just tracking it as such.


Which I guess brings me back to: Should DD-WRT count these transactions as connections even though they aren't actually open connections? Even though it's basically just a misnomer and a placeholder? You say it's hard to get an actual count, but still..
Display posts from previous:    Page 1 of 1
Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Broadcom SoC based Hardware All times are GMT

Navigation

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum