LinuxQuestions.org
Welcome to the most active Linux Forum on the web.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Networking
User Name
Password
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

Notices


Reply
  Search this Thread
Old 06-09-2010, 03:20 AM   #1
geddysekar
LQ Newbie
 
Registered: Mar 2010
Posts: 18

Rep: Reputation: 0
/proc/net/snmp file: what OutRsts tells?


Hi,

What does OutRsts specify in /proc/net/snmp file?

In which condition the tcpOutRsts in /proc/net/snmp file will show higher value?

Regards,
GeddySekar
 
Old 06-09-2010, 04:08 AM   #2
unSpawn
Moderator
 
Registered: May 2001
Posts: 29,409
Blog Entries: 55

Rep: Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582
In http://fxr.watson.org/fxr/source/net...excerpts#L2182 see:
Code:
 2156 /* We get here when a process closes a file descriptor (either due to
 2157  * an explicit close() or as a byproduct of exit()'ing) and there
 2158  * was unread data in the receive queue.  This behavior is recommended
 2159  * by RFC 2525, section 2.17.  -DaveM
 2160  */
 2161 void tcp_send_active_reset(struct sock *sk, gfp_t priority)
 2162 {
 2163         struct sk_buff *skb;
 2164 
 2165         /* NOTE: No TCP options attached and we never retransmit this. */
 2166         skb = alloc_skb(MAX_TCP_HEADER, priority);
 2167         if (!skb) {
 2168                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
 2169                 return;
 2170         }
 2171 
 2172         /* Reserve space for headers and prepare control bits. */
 2173         skb_reserve(skb, MAX_TCP_HEADER);
 2174         tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
 2175                              TCPCB_FLAG_ACK | TCPCB_FLAG_RST);
 2176         /* Send it off. */
 2177         TCP_SKB_CB(skb)->when = tcp_time_stamp;
 2178         if (tcp_transmit_skb(sk, skb, 0, priority))
 2179                 NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTFAILED);
 2180 
 2181         TCP_INC_STATS(sock_net(sk), TCP_MIB_OUTRSTS);
 2182 }
and see http://www.faqs.org/rfcs/rfc2525.html (Failure to RST on close with data pending) for more?

BTW, you have been warned before that you should not post threads twice. Do not do that again!
 
1 members found this post helpful.
Old 06-11-2010, 08:58 AM   #3
geddysekar
LQ Newbie
 
Registered: Mar 2010
Posts: 18

Original Poster
Rep: Reputation: 0
Hi,

I have given the following details below from /proc/net/snmp file.
And I illustrated the details of particular Linux server.

___________________________________________________________________________
| ActiveOpens | PassiveOpens | CurrEstb | OutRsts | ___________________________________________________________________________
| 2 | 2 | 34 | 160 |
| 6 | 4 | 33 | 240 |
| 7 | 6 | 37 | 240 |
___________________________________________________________________________

I mentioned in above table, only incremented values (difference from previous and present) for each 5 seconds. i.e., First row in 5th seconds, second row on 10th seconds and third row on 15th seconds.

In which condition, we can receive these OutRsts vale as high?

And also, from the above table, I understand that only 33 to 37 established connections are available, but how can we get the OutRsts value more than the Established connection value?

Regards,
GeddySekar
 
Old 06-12-2010, 04:28 AM   #4
unSpawn
Moderator
 
Registered: May 2001
Posts: 29,409
Blog Entries: 55

Rep: Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582Reputation: 3582
Quote:
Originally Posted by geddysekar View Post
In which condition, we can receive these OutRsts vale as high?
See RFC 2525 "Known TCP Implementation Problems", section 2.17 "Failure to RST on close with data pending".


Quote:
Originally Posted by geddysekar View Post
how can we get the OutRsts value more than the Established connection value?
If I read RFC 2525 section 2.17 right it says that if a local server (used connection) is closed down it will need to send RSTs to the remote client if that client is still sending data or if received data is not (no longer) read.

I suggest you be way, way more verbose and list your full network, platform, application (and testbed), configuration and tuning details.
 
1 members found this post helpful.
Old 09-17-2010, 04:57 AM   #5
geddysekar
LQ Newbie
 
Registered: Mar 2010
Posts: 18

Original Poster
Rep: Reputation: 0
Thanks a lot. Link was very help. In our scenario, Tcp OutRsts is sent when java application server is closed abnormally.
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Integrate Mod-Apache-Snmp with Net-SNMP source kirukan Linux - Server 2 05-11-2011 01:48 AM
when the tcpOutRsts in /proc/net/snmp will be high value geddysekar Linux - Kernel 1 06-09-2010 03:46 AM
Net-Snmp: Cannot extend agent to run script from configuration file skatersam0 Linux - Networking 2 06-30-2009 11:11 AM
Net-SNMP writing a Subagent - snmp.conf Unknown token: master AustinMarton Programming 0 12-16-2008 07:34 PM
Net-Snmp perl scripts failed to open file ohcarol Linux - Software 2 08-17-2008 07:48 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 03:03 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration