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Groups > comp.os.linux.networking > #4992
| From | William Unruh <unruh@invalid.ca> |
|---|---|
| Newsgroups | comp.os.linux.networking |
| Subject | Re: incoming ssh blocked by ISP |
| Date | 2021-11-07 03:03 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <sm7fmd$378$2@dont-email.me> (permalink) |
| References | <sm66vk$hvp$1@dont-email.me> <sm6af0$sst$1@dont-email.me> <sm6sb6$kru$1@dont-email.me> <sm6tj9$sst$2@dont-email.me> |
On 2021-11-06, Lew Pitcher <lew.pitcher@digitalfreehold.ca> wrote: > On Sat, 06 Nov 2021 21:33:27 +0000, Bob Tennent wrote: > >> On Sat, 6 Nov 2021 16:28:16 -0000 (UTC), Lew Pitcher wrote: >> > On Sat, 06 Nov 2021 15:28:52 +0000, Bob Tennent wrote: >> > >> >> Outgoing ssh works fine and sshd is active. It's not my >> >> firewall and I use ddclient and zoneedit.com to deal with my >> >> dynamic IP address. >> >> >> >> When I complain to Support at my ISP I'm told to pay for a >> >> static IP address. Is there any other solution? >> > >> > ISPs sell "internet connectivity" to clients, and most consumer- >> > grade ISPs block datagrams coming from the internet to certain >> > well-known ports, often either because they "represent a security >> > exposure" to the client, or because the ISP would like to gain >> > an additional income from "power users" by up-selling them on >> > internet connectivity that they do not deliberately block. >> > >> > It sounds like your ISP falls into that second category. >> > >> > Outside of capitulating to the ISP's up-selling requirement, >> > or changing your ISP to one that does not block incoming SSH, >> > the only reliable way I can think of to bypass your ISP's >> > block is to change the port on which you listen for SSH connections. >> >> That doesn't work. The ISP doesn't allow access of any sort >> to the system. > > Nonsense. If your ISP blocks /all/ inbound ports, then your system is > effectively /not/ connected to the internet: both TCP and UDP require > that /some/ port be open on each side of the conversation. > > However, if your ISP really "doesn't allow access of any sort to the > system", then what are you paying them for? > It is a NATted system. He has a local address of something like 10.5.23.199 The ISPs router than takes an outgoing packet addressed say as orginating from 10.5.23.199 port 22 and translates that from address as originating from the router's address (say 137.29.13.114) and some random high port, say 22945. It keeps a tanslation table which says if a packet comes to that port then send it out to the internal address 10.5.23.199 port 22. That translation table keeps changing and thus there is no way that anyone outside would know which port to send anything to. HOwever external machines now how to replay to packets because the proper reply address and port is part of the packet. Thus nothing independent can get in, but the inside machines can connect to the outside. >
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incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-06 15:28 +0000
Re: incoming ssh blocked by ISP Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-11-06 16:28 +0000
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-06 21:33 +0000
Re: incoming ssh blocked by ISP Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-11-06 21:54 +0000
Re: incoming ssh blocked by ISP "Carlos E. R." <robin_listas@es.invalid> - 2021-11-06 23:13 +0100
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-06 19:16 -0400
Re: incoming ssh blocked by ISP "Carlos E. R." <robin_listas@es.invalid> - 2021-11-07 00:28 +0100
Re: incoming ssh blocked by ISP William Unruh <unruh@invalid.ca> - 2021-11-07 03:03 +0000
Re: incoming ssh blocked by ISP Marco Moock <invalid@invalid.invalid> - 2021-11-07 12:44 +0100
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-06 17:57 -0400
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-06 18:01 -0400
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-07 01:56 +0000
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-07 21:21 +0000
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-07 19:05 -0500
Re: incoming ssh blocked by ISP ant@zimage.comANT (Ant) - 2021-11-07 22:51 -0600
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-08 01:18 +0000
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-07 21:25 -0500
Re: incoming ssh blocked by ISP Bit Twister <BitTwister@mouse-potato.com> - 2021-11-07 23:35 -0600
Re: incoming ssh blocked by ISP William Unruh <unruh@invalid.ca> - 2021-11-07 02:51 +0000
Re: incoming ssh blocked by ISP "Carlos E. R." <robin_listas@es.invalid> - 2021-11-06 22:47 +0100
Re: incoming ssh blocked by ISP Dan Purgert <dan@djph.net> - 2021-11-10 13:13 +0000
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-06 13:43 -0400
Re: incoming ssh blocked by ISP Pascal Hambourg <pascal@plouf.fr.eu.org> - 2021-11-06 19:18 +0100
Re: incoming ssh blocked by ISP Marco Moock <invalid@invalid.invalid> - 2021-11-06 19:35 +0100
Re: incoming ssh blocked by ISP William Unruh <unruh@invalid.ca> - 2021-11-06 19:54 +0000
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-06 21:18 +0000
Re: incoming ssh blocked by ISP "Carlos E. R." <robin_listas@es.invalid> - 2021-11-06 22:47 +0100
Re: incoming ssh blocked by ISP "Carlos E. R." <robin_listas@es.invalid> - 2021-11-06 23:56 +0100
Re: incoming ssh blocked by ISP Pascal Hambourg <pascal@plouf.fr.eu.org> - 2021-11-06 23:44 +0100
Re: incoming ssh blocked by ISP "Carlos E. R." <robin_listas@es.invalid> - 2021-11-06 23:54 +0100
Re: incoming ssh blocked by ISP Pascal Hambourg <pascal@plouf.fr.eu.org> - 2021-11-07 10:07 +0100
Re: incoming ssh blocked by ISP Marco Moock <invalid@invalid.invalid> - 2021-11-07 10:22 +0100
Re: incoming ssh blocked by ISP Pascal Hambourg <pascal@plouf.fr.eu.org> - 2021-11-07 10:51 +0100
Re: incoming ssh blocked by ISP Marco Moock <invalid@invalid.invalid> - 2021-11-07 11:09 +0100
Re: incoming ssh blocked by ISP Joe Beanfish <joebeanfish@nospam.duh> - 2021-11-08 14:52 +0000
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-14 16:42 +0000
Re: incoming ssh blocked by ISP Marco Moock <mo01@posteo.de> - 2021-11-14 18:01 +0100
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-14 13:08 -0500
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-14 19:20 +0000
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-14 15:06 -0500
Re: incoming ssh blocked by ISP Bob Tennent <rdtennent@tennent.ca> - 2021-11-14 21:03 +0000
Re: incoming ssh blocked by ISP "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2021-11-14 16:28 -0500
Re: incoming ssh blocked by ISP ant@zimage.comANT (Ant) - 2021-11-15 04:19 -0600
Re: incoming ssh blocked by ISP William Unruh <unruh@invalid.ca> - 2021-11-15 20:18 +0000
Re: incoming ssh blocked by ISP ant@zimage.comANT (Ant) - 2021-11-15 04:18 -0600
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