> On 17. Jul 2019, at 18:09, Kevin Bowling <kevin.bowl...@kev009.com> wrote: > > Any knowledge of the endpoints, Linux boxes misconfigured with tcp_tw_recycle? I contacted some Linux guys and they told me that tcp_tw_recycle is specific to the 5 tuple. Is that not correct? The servers can be running Linux, I haven't checked all of them...
For the problem we are seeing here, it port numbers are irrelevant. If the server sends a FIN (and therefore goes to TIMEWAIT), one can experience the problem, even if the client changes the port number and even if you talk to other server ports. I tested with the ssh port in addition to the web traffic. Best regards Michael > > On Wed, Jul 17, 2019 at 5:42 AM Michael Tuexen <tue...@freebsd.org> wrote: > > On 17. Jul 2019, at 14:32, Vitalij Satanivskij <sa...@ukr.net> wrote: > > > > Hmm, looks like with some host's work but not with another > > > > Wed/17.07:/home/satan > > hell:-1522/15:28>curl https://volia.com > /dev/null > > % Total % Received % Xferd Average Speed Time Time Time > > Current > > Dload Upload Total Spent Left Speed > > 100 41519 0 41519 0 0 137k 0 --:--:-- --:--:-- --:--:-- > > 137k > > Wed/17.07:/home/satan > > hell:-1523/15:28>curl https://volia.com > /dev/null > > % Total % Received % Xferd Average Speed Time Time Time > > Current > > Dload Upload Total Spent Left Speed > > 0 0 0 0 0 0 0 0 --:--:-- 0:00:53 --:--:-- > > 0^C > > Wed/17.07:/home/satan > > hell:-1524/15:29>sysctl net.inet.tcp.rexmit_drop_options > > net.inet.tcp.rexmit_drop_options: 1 > OK, I can confirm that for https://volia.com only a timeout helps. > > What I observed for now is that for the "blocking" to occur is it crucial that > the server sends the FIN and therefore goes into the TIMEWAIT state. The > timeout > seems to be 60 seconds. > The blocking is also not limited to a single server port. > > I'm not sure yet whether it is a broken end point or a broken middle box. > > Best regards > Michael > > > > But > > > > MT> Interesting. It works for me: > > MT> > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 33637 0 --:--:-- --:--:-- > > --:--:-- 33575 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 4834 0 --:--:-- 0:00:03 > > --:--:-- 4833 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 35813 0 --:--:-- --:--:-- > > --:--:-- 35813 > > MT> tuexen@head:~ % time curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 48320 0 --:--:-- --:--:-- > > --:--:-- 48320 > > MT> 0.012u 0.031s 0:00.39 10.2% 140+245k 0+0io 0pf+0w > > MT> tuexen@head:~ % time curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 4592 0 --:--:-- 0:00:03 > > --:--:-- 4591 > > MT> 0.031u 0.010s 0:03.99 1.0% 80+140k 0+0io 0pf+0w > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 37815 0 --:--:-- --:--:-- > > --:--:-- 37737 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 27261 0 --:--:-- --:--:-- > > --:--:-- 27220 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 4533 0 --:--:-- 0:00:04 > > --:--:-- 4533 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 48320 0 --:--:-- --:--:-- > > --:--:-- 48192 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 4746 0 --:--:-- 0:00:03 > > --:--:-- 4745 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 4500 0 --:--:-- 0:00:04 > > --:--:-- 4767 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 4726 0 --:--:-- 0:00:03 > > --:--:-- 4726 > > MT> tuexen@head:~ % curl https://vitagramma.com > /dev/null > > MT> % Total % Received % Xferd Average Speed Time Time Time > > Current > > MT> Dload Upload Total Spent Left > > Speed > > MT> 100 18265 0 18265 0 0 34268 0 --:--:-- --:--:-- > > --:--:-- 34332 > > MT> tuexen@head:~ % > > MT> > > MT> So it either works immediately or with a delay of 3 to 4 seconds... > > MT> > > MT> Best regards > > MT> Michael > > MT> > > > MT> > > > MT> > MT> > > MT> > MT> Option 2: Disable the TCP timestamps (and window scaling) > > MT> > MT> To enable this, you configure on the client > > MT> > MT> sudo sysctl -w net.inet.tcp.rfc1323=0 > > MT> > MT> or put > > MT> > MT> net.inet.tcp.rfc1323=0 > > MT> > MT> in /etc/sysctl.conf > > MT> > MT> and reboot. > > MT> > MT> This disables the timestamp option and window scaling completely. > > This allows you to > > MT> > MT> setup the connections without any delay. However, you don't have > > the benefits of the > > MT> > MT> extension. > > MT> > MT> > > MT> > MT> Both options don't require any code changes. > > MT> > > > MT> > This option was tested some time before. Yep it's help. But overal > > performance of tcp networking ... Let's say to bad :( > > MT> > > > MT> > > > MT> > > > MT> > > > MT> > MT> Best regards > > MT> > MT> Michael > > MT> > MT> > > MT> > MT> > > MT> > MT> > > > MT> > MT> > > > MT> > MT> > MT> > > MT> > MT> > MT> Best regards > > MT> > MT> > MT> Michael > > MT> > MT> > MT> > > > MT> > MT> > MT> > > > MT> > MT> > MT> > > > MT> > MT> > MT> > Michael Tuexen wrote: > > MT> > MT> > MT> > MT> > > MT> > MT> > MT> > MT> > > MT> > MT> > MT> > MT> > On 9. Jul 2019, at 14:58, Paul <de...@ukr.net> > > wrote: > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > Hi Michael, > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > 9 July 2019, 15:34:29, by "Michael Tuexen" > > <tue...@freebsd.org>: > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >>> On 8. Jul 2019, at 17:22, Paul <de...@ukr.net> > > wrote: > > MT> > MT> > MT> > MT> >>> > > MT> > MT> > MT> > MT> >>> > > MT> > MT> > MT> > MT> >>> > > MT> > MT> > MT> > MT> >>> 8 July 2019, 17:12:21, by "Michael Tuexen" > > <tue...@freebsd.org>: > > MT> > MT> > MT> > MT> >>> > > MT> > MT> > MT> > MT> >>>>> On 8. Jul 2019, at 15:24, Paul <de...@ukr.net> > > wrote: > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> Hi Michael, > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> 8 July 2019, 15:53:15, by "Michael Tuexen" > > <tue...@freebsd.org>: > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>>>> On 8. Jul 2019, at 12:37, Paul > > <de...@ukr.net> wrote: > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> Hi team, > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> Recently we had an upgrade to 12 Stable. > > Immediately after, we have started > > MT> > MT> > MT> > MT> >>>>>>> seeing some strange connection establishment > > timeouts to some fixed number > > MT> > MT> > MT> > MT> >>>>>>> of external (world) hosts. The issue was > > persistent and easy to reproduce. > > MT> > MT> > MT> > MT> >>>>>>> Thanks to a patience and dedication of our > > system engineer we have tracked > > MT> > MT> > MT> > MT> >>>>>>> this issue down to a specific commit: > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> > > https://svnweb.freebsd.org/base?view=revision&revision=338053 > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> This patch was also back-ported into 11 > > Stable: > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> > > https://svnweb.freebsd.org/base?view=revision&revision=348435 > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> Among other things this patch changes the > > timestamp allocation strategy, > > MT> > MT> > MT> > MT> >>>>>>> by introducing a deterministic randomness via > > a hash function that takes > > MT> > MT> > MT> > MT> >>>>>>> into account a random key as well as source > > address, source port, dest > > MT> > MT> > MT> > MT> >>>>>>> address and dest port. As the result, > > timestamp offsets of different > > MT> > MT> > MT> > MT> >>>>>>> tuples (SA,SP,DA,DP) will be wildly different > > and will jump from small > > MT> > MT> > MT> > MT> >>>>>>> to large numbers and back, as long as > > something in the tuple changes. > > MT> > MT> > MT> > MT> >>>>>> Hi Paul, > > MT> > MT> > MT> > MT> >>>>>> > > MT> > MT> > MT> > MT> >>>>>> this is correct. > > MT> > MT> > MT> > MT> >>>>>> > > MT> > MT> > MT> > MT> >>>>>> Please note that the same happens with the old > > method, if two hosts with > > MT> > MT> > MT> > MT> >>>>>> different uptimes are bind a consumer grade > > NAT. > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> If NAT does not replace timestamps then yes, it > > should be the case. > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> After performing various tests of hosts that > > produce the above mentioned > > MT> > MT> > MT> > MT> >>>>>>> issue we came to conclusion that there are > > some interesting implementations > > MT> > MT> > MT> > MT> >>>>>>> that drop SYN packets with timestamps smaller > > than the largest timestamp > > MT> > MT> > MT> > MT> >>>>>>> value from streams of all recent or current > > connections from a specific > > MT> > MT> > MT> > MT> >>>>>>> address. This looks as some kind of SYN flood > > protection. > > MT> > MT> > MT> > MT> >>>>>> This also breaks multiple hosts with different > > uptimes behind a consumer > > MT> > MT> > MT> > MT> >>>>>> level NAT talking to such a server. > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> To ensure that each external host is not > > going to see a wild jumps of > > MT> > MT> > MT> > MT> >>>>>>> timestamp values I propose a patch that > > removes ports from the equation > > MT> > MT> > MT> > MT> >>>>>>> all together, when calculating the timestamp > > offset: > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> Index: sys/netinet/tcp_subr.c > > MT> > MT> > MT> > MT> >>>>>>> > > =================================================================== > > MT> > MT> > MT> > MT> >>>>>>> --- sys/netinet/tcp_subr.c (revision > > 348435) > > MT> > MT> > MT> > MT> >>>>>>> +++ sys/netinet/tcp_subr.c (working copy) > > MT> > MT> > MT> > MT> >>>>>>> @@ -2224,7 +2224,22 @@ > > MT> > MT> > MT> > MT> >>>>>>> uint32_t > > MT> > MT> > MT> > MT> >>>>>>> tcp_new_ts_offset(struct in_conninfo *inc) > > MT> > MT> > MT> > MT> >>>>>>> { > > MT> > MT> > MT> > MT> >>>>>>> - return (tcp_keyed_hash(inc, > > V_ts_offset_secret)); > > MT> > MT> > MT> > MT> >>>>>>> + /* > > MT> > MT> > MT> > MT> >>>>>>> + * Some implementations show a > > strange behaviour when a wildly random > > MT> > MT> > MT> > MT> >>>>>>> + * timestamps allocated for > > different streams. It seems that only the > > MT> > MT> > MT> > MT> >>>>>>> + * SYN packets are affected. > > Observed implementations drop SYN packets > > MT> > MT> > MT> > MT> >>>>>>> + * with timestamps smaller than the > > largest timestamp value of all > > MT> > MT> > MT> > MT> >>>>>>> + * recent or current connections > > from specific a address. To mitigate > > MT> > MT> > MT> > MT> >>>>>>> + * this we are going to ensure that > > each host will always observe > > MT> > MT> > MT> > MT> >>>>>>> + * timestamps as increasing no > > matter the stream: by dropping ports > > MT> > MT> > MT> > MT> >>>>>>> + * from the equation. > > MT> > MT> > MT> > MT> >>>>>>> + */ > > MT> > MT> > MT> > MT> >>>>>>> + struct in_conninfo inc_copy = *inc; > > MT> > MT> > MT> > MT> >>>>>>> + > > MT> > MT> > MT> > MT> >>>>>>> + inc_copy.inc_fport = 0; > > MT> > MT> > MT> > MT> >>>>>>> + inc_copy.inc_lport = 0; > > MT> > MT> > MT> > MT> >>>>>>> + > > MT> > MT> > MT> > MT> >>>>>>> + return (tcp_keyed_hash(&inc_copy, > > V_ts_offset_secret)); > > MT> > MT> > MT> > MT> >>>>>>> } > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> /* > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> In any case, the solution of the uptime leak, > > implemented in rev338053 is > > MT> > MT> > MT> > MT> >>>>>>> not going to suffer, because a supposed > > attacker is currently able to use > > MT> > MT> > MT> > MT> >>>>>>> any fixed values of SP and DP, albeit not 0, > > anyway, to remove them out > > MT> > MT> > MT> > MT> >>>>>>> of the equation. > > MT> > MT> > MT> > MT> >>>>>> Can you describe how a peer can compute the > > uptime from two observed timestamps? > > MT> > MT> > MT> > MT> >>>>>> I don't see how you can do that... > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> Supposed attacker could run a script that > > continuously monitors timestamps, > > MT> > MT> > MT> > MT> >>>>> for example via a periodic TCP connection from > > a fixed local port (eg 12345) > > MT> > MT> > MT> > MT> >>>>> and a fixed local address to the fixed victim's > > address and port (eg 80). > > MT> > MT> > MT> > MT> >>>>> Whenever large discrepancy is observed, > > attacker can assume that reboot has > > MT> > MT> > MT> > MT> >>>>> happened (due to V_ts_offset_secret > > re-generation), hence the received > > MT> > MT> > MT> > MT> >>>>> timestamp is considered an approximate point of > > reboot from which the uptime > > MT> > MT> > MT> > MT> >>>>> can be calculated, until the next reboot and so > > on. > > MT> > MT> > MT> > MT> >>>> Ahh, I see. The patch we are talking about is > > not intended to protect against > > MT> > MT> > MT> > MT> >>>> continuous monitoring, which is something you > > can always do. You could even > > MT> > MT> > MT> > MT> >>>> watch for service availability and detect > > reboots. A change of the local key > > MT> > MT> > MT> > MT> >>>> would also look similar to a reboot without a > > temporary loss of connectivity. > > MT> > MT> > MT> > MT> >>>> > > MT> > MT> > MT> > MT> >>>> Thanks for the clarification. > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> There is the list of example hosts that we > > were able to reproduce the > > MT> > MT> > MT> > MT> >>>>>>> issue with: > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> curl -v http://88.99.60.171:80 > > MT> > MT> > MT> > MT> >>>>>>> curl -v http://163.172.71.252:80 > > MT> > MT> > MT> > MT> >>>>>>> curl -v http://5.9.242.150:80 > > MT> > MT> > MT> > MT> >>>>>>> curl -v https://185.134.205.105:443 > > MT> > MT> > MT> > MT> >>>>>>> curl -v https://136.243.1.231:443 > > MT> > MT> > MT> > MT> >>>>>>> curl -v https://144.76.196.4:443 > > MT> > MT> > MT> > MT> >>>>>>> curl -v http://94.127.191.194:80 > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> To reproduce, call curl repeatedly with a > > same URL some number of times. > > MT> > MT> > MT> > MT> >>>>>>> You are going to see some of the requests > > stuck in > > MT> > MT> > MT> > MT> >>>>>>> `* Trying XXX.XXX.XXX.XXX...` > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> For some reason, the easiest way to reproduce > > the issue is with nc: > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> $ echo "foooooo" | nc -v 88.99.60.171 80 > > MT> > MT> > MT> > MT> >>>>>>> > > MT> > MT> > MT> > MT> >>>>>>> Only a few such calls are required until one > > of them is stuck on connect(): > > MT> > MT> > MT> > MT> >>>>>>> issuing SYN packets with an exponential > > backoff. > > MT> > MT> > MT> > MT> >>>>>> Thanks for providing an end-point to test > > with. I'll take a look. > > MT> > MT> > MT> > MT> >>>>>> Just to be clear: You are running a FreeBSD > > client against one of the above > > MT> > MT> > MT> > MT> >>>>>> servers and experience the problem with the > > new timestamp computations. > > MT> > MT> > MT> > MT> >>>>>> > > MT> > MT> > MT> > MT> >>>>>> You are not running arbitrary clients against > > a FreeBSD server... > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> We are talking about FreeBSD being the client. > > Peers that yield this unwanted > > MT> > MT> > MT> > MT> >>>>> behaviour are unknown. Little bit of tinkering > > showed that some of them run > > MT> > MT> > MT> > MT> >>>>> Debian: > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> telnet 88.99.60.171 22 > > MT> > MT> > MT> > MT> >>>>> Trying 88.99.60.171... > > MT> > MT> > MT> > MT> >>>>> Connected to 88.99.60.171. > > MT> > MT> > MT> > MT> >>>>> Escape character is '^]'. > > MT> > MT> > MT> > MT> >>>>> SSH-2.0-OpenSSH_6.7p1 Debian-5+deb8u3 > > MT> > MT> > MT> > MT> >>>> Also some are hosted by Hetzner, but not all. > > I'll will look into > > MT> > MT> > MT> > MT> >>>> this tomorrow, since I'm on a deadline today > > (well it is 2am tomorrow > > MT> > MT> > MT> > MT> >>>> morning, to be precise)... > > MT> > MT> > MT> > MT> >>> > > MT> > MT> > MT> > MT> >>> Thanks a lot, I would appreciate that. > > MT> > MT> > MT> > MT> >> Hi Paul, > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> I have looked into this. > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> * The FreeBSD behaviour is the one which is > > specified in the last bullet item > > MT> > MT> > MT> > MT> >> in https://tools.ietf.org/html/rfc7323#section-5.4 > > MT> > MT> > MT> > MT> >> It is also the one, which is RECOMMENDED in > > MT> > MT> > MT> > MT> >> https://tools.ietf.org/html/rfc7323#section-7.1 > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> * My NAT box (a popular one in Germany) does NOT > > rewrite TCP timestamps. > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> This means that the host you are referring to have > > some sort of protection, > > MT> > MT> > MT> > MT> >> which makes incorrect assumptions. It will also > > break multiple hosts behind > > MT> > MT> > MT> > MT> >> a NAT. > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> I can run > > MT> > MT> > MT> > MT> >> curl -v http://88.99.60.171:80 > > MT> > MT> > MT> > MT> >> in a loop without any problems from a FreeBSD head > > system. I tested 1000 > > MT> > MT> > MT> > MT> >> iterations or so. The TS.val is jumping up and > > down as expected. > > MT> > MT> > MT> > MT> >> I'm wondering why you are observing errors in this > > case, too. > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> However, doing something like > > MT> > MT> > MT> > MT> >> echo "foooooo" | nc -v 88.99.60.171 80 > > MT> > MT> > MT> > MT> >> triggers the problem. > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> So I think there is some functionality (in a > > middlebox or running on the host), > > MT> > MT> > MT> > MT> >> which incorrectly assume monotonic timestamps > > between multiple TCP connections > > MT> > MT> > MT> > MT> >> coming from the same IP address, but only in case > > of errors at the application layer. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > Yeah, exactly, some hosts seem to enable this only > > in case of an error in HTTP > > MT> > MT> > MT> > MT> > communication (some smart proxy?). However, there > > are some that behave this way > > MT> > MT> > MT> > MT> > regardless of errors, for example these: > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > curl -v https://185.134.205.105:443 > > MT> > MT> > MT> > MT> > curl -v https://136.243.1.231:443 > > MT> > MT> > MT> > MT> Wireshark sees an Encrypted Alert in both cases. So I > > guess this is another indication > > MT> > MT> > MT> > MT> of "error at the application layer". > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> Do you have any insights whether the hosts you are > > listed share something in > > MT> > MT> > MT> > MT> >> common. Some of them are hosted by Hetzner, but > > not all. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > Nope. A whole set of endpoints that we have > > detected so far is pretty diverse, > > MT> > MT> > MT> > MT> > containing a lot of different locations > > geographically, as well as different > > MT> > MT> > MT> > MT> > hosters. > > MT> > MT> > MT> > MT> OK. Thanks for the clarification. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> I think in general, it is the correct thing to > > include the port numbers in > > MT> > MT> > MT> > MT> >> the offset computation. We might add a sysctl > > variable to control the inclusion. > > MT> > MT> > MT> > MT> >> This would allow interworking with broken > > middleboxes. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > Yeah, I completely agree that these rare cases > > should not dictate the implementation. > > MT> > MT> > MT> > MT> > But an ability to enable a work-around via sysctl > > would be greatly appreciated. > > MT> > MT> > MT> > MT> > Currently we are unable to roll-out the upgrade > > across all servers because of this > > MT> > MT> > MT> > MT> > issue: even though it happens not so often, a lot > > of requests from our users > > MT> > MT> > MT> > MT> > get stuck or fail all together. For example, a host > > 185.134.205.105 is a kind of > > MT> > MT> > MT> > MT> > social network that our proxy servers connect to so > > securely access to content, > > MT> > MT> > MT> > MT> > such as images, on behalf of our users. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> Please note, this does not fix the case of > > multiple clients behind a NAT. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > Yeah, that's true. Fortunately we don't use NAT. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> I'm also trying to figure out how and why Linux > > and Windows are handling this. > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> > Thanks for bothering! > > MT> > MT> > MT> > MT> Will let you know what I figure out. > > MT> > MT> > MT> > MT> > > MT> > MT> > MT> > MT> Best regards > > MT> > MT> > MT> > MT> Michael > > MT> > MT> > MT> > MT> > > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> Best regards > > MT> > MT> > MT> > MT> >> Michael > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >>> > > MT> > MT> > MT> > MT> >>>> > > MT> > MT> > MT> > MT> >>>> Best regards > > MT> > MT> > MT> > MT> >>>> Michael > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>> > > MT> > MT> > MT> > MT> >>>>>> > > MT> > MT> > MT> > MT> >>>>>> Best regards > > MT> > MT> > MT> > MT> >>>>>> Michael > > MT> > MT> > MT> > MT> >>>>>> > > MT> > MT> > MT> > MT> >>>>>> > > MT> > MT> > MT> > MT> >>>> > > MT> > MT> > MT> > MT> >>>> > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> >> > > MT> > MT> > MT> > MT> > > MT> > MT> > MT> > MT> _______________________________________________ > > MT> > MT> > MT> > MT> freebsd-net@freebsd.org mailing list > > MT> > MT> > MT> > MT> https://lists.freebsd.org/mailman/listinfo/freebsd-net > > MT> > MT> > MT> > MT> To unsubscribe, send any mail to > > "freebsd-net-unsubscr...@freebsd.org" > > MT> > MT> > MT> > > MT> > MT> > MT> _______________________________________________ > > MT> > MT> > MT> freebsd-net@freebsd.org mailing list > > MT> > MT> > MT> https://lists.freebsd.org/mailman/listinfo/freebsd-net > > MT> > MT> > MT> To unsubscribe, send any mail to > > "freebsd-net-unsubscr...@freebsd.org" > > MT> > MT> > > MT> > _______________________________________________ > > MT> > freebsd-net@freebsd.org mailing list > > MT> > https://lists.freebsd.org/mailman/listinfo/freebsd-net > > MT> > To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" > > MT> > > _______________________________________________ > > freebsd-net@freebsd.org mailing list > > https://lists.freebsd.org/mailman/listinfo/freebsd-net > > To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" > > _______________________________________________ > freebsd-net@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org" _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
