Re: What is the timeout of TCP in freeBSD?
On Sun, Jan 20, 2013 at 9:38 PM, Karthik Reddy <22karthikre...@gmail.com>wrote: > When I change the kern.hz to 50, the timeout is happening at 76sec. Could > you please elaborate on kern.hz and how does it effect timing. > Lower frequency so less opportunities for errors to be introduced, although you may have greater network latency at that setting. Some setting under sysctl kern.timecounter and/or sysctl kern.eventtimer should be able to allow the guest to run better if the hypervisor can't do it. -- Adam Vande More ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: What is the timeout of TCP in freeBSD?
When I change the kern.hz to 50, the timeout is happening at 76sec. Could you please elaborate on kern.hz and how does it effect timing. On Sun, Jan 20, 2013 at 10:12 PM, Adam Vande More wrote: > On Sun, Jan 20, 2013 at 8:50 AM, Karthik Reddy > <22karthikre...@gmail.com>wrote: > >> I was doing a experiment on FreeBSD for testing TCP timeout and RTO. OS is >> being run from two different VMware versions 4.0 and 5.0. >> >> Present Scenario: VMware Player 4.0 >> I'll start a telnet session to a non-existing system in the network. When >> I >> look at the tcpdump the RTO starts at every 3 seconds and after some >> exponential backoff starts. In this scenario after 75 seconds the TCP >> gives >> up and tells me that there is no system existing with the IP and telnet >> session terminates. >> >> Next Scenario: VMware Player 5.0 >> In this scenario, I did the same but the RTO starts at 5 sec and then >> varies. In this scenario, it takes more than 120 seconds for telnet >> session >> to tell me that there is no system is available in the network. >> >> I have seen sysctl in both VM's. net.inet.tcp.keepinit = 75000 >> >> Is this problem something related to timing of the VM's or any other >> issue? >> > > What's the wallclock delta during such a test? Have you tried setting > 'kern.hz="50"' or fiddling other TC options? UP VM's tend to keep time > better than other multicore configs. > > -- > Adam Vande More -- Karthik Reddy I'm not the best, but I'm not like the Rest ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: What is the timeout of TCP in freeBSD?
On Sun, Jan 20, 2013 at 8:50 AM, Karthik Reddy <22karthikre...@gmail.com>wrote: > I was doing a experiment on FreeBSD for testing TCP timeout and RTO. OS is > being run from two different VMware versions 4.0 and 5.0. > > Present Scenario: VMware Player 4.0 > I'll start a telnet session to a non-existing system in the network. When I > look at the tcpdump the RTO starts at every 3 seconds and after some > exponential backoff starts. In this scenario after 75 seconds the TCP gives > up and tells me that there is no system existing with the IP and telnet > session terminates. > > Next Scenario: VMware Player 5.0 > In this scenario, I did the same but the RTO starts at 5 sec and then > varies. In this scenario, it takes more than 120 seconds for telnet session > to tell me that there is no system is available in the network. > > I have seen sysctl in both VM's. net.inet.tcp.keepinit = 75000 > > Is this problem something related to timing of the VM's or any other issue? > What's the wallclock delta during such a test? Have you tried setting 'kern.hz="50"' or fiddling other TC options? UP VM's tend to keep time better than other multicore configs. -- Adam Vande More ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
What is the timeout of TCP in freeBSD?
I was doing a experiment on FreeBSD for testing TCP timeout and RTO. OS is being run from two different VMware versions 4.0 and 5.0. Present Scenario: VMware Player 4.0 I'll start a telnet session to a non-existing system in the network. When I look at the tcpdump the RTO starts at every 3 seconds and after some exponential backoff starts. In this scenario after 75 seconds the TCP gives up and tells me that there is no system existing with the IP and telnet session terminates. Next Scenario: VMware Player 5.0 In this scenario, I did the same but the RTO starts at 5 sec and then varies. In this scenario, it takes more than 120 seconds for telnet session to tell me that there is no system is available in the network. I have seen sysctl in both VM's. net.inet.tcp.keepinit = 75000 Is this problem something related to timing of the VM's or any other issue? -- Karthik Reddy I'm not the best, but I'm not like the Rest ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"