ppp inside private network, but no DNS returned?
Hey - we've got a fun little problem happening right now. We're connecting a Linux box via LTE to a client's private network. They want us to connect to a host on that network and upload files via sftp. We've demonstrated that all of this works with every other LTE network, but in their walled garden LTE network, they're not returning any DNS server, so we can't find the host at all. This network does not have access to public DNS. Does one usually have to poke a ppp connection a little more to get useful routing information, or should we have "just got" all the gateway and DNS details on first connection? Stewart (as you can tell, I'm not a network person, but we might appreciate finding one and paying for support)
On 2023-02-28 14:50, Stewart Russell via talk wrote:
Hey - we've got a fun little problem happening right now.
We're connecting a Linux box via LTE to a client's private network. They want us to connect to a host on that network and upload files via sftp. We've demonstrated that all of this works with every other LTE network, but in their walled garden LTE network, they're not returning any DNS server, so we can't find the host at all. This network does not have access to public DNS.
Does one usually have to poke a ppp connection a little more to get useful routing information, or should we have "just got" all the gateway and DNS details on first connection?
Stewart (as you can tell, I'm not a network person, but we might appreciate finding one and paying for support)
Doesn't the PPP server normally provide the DNS address? https://www.rfc-editor.org/rfc/rfc1877.html#section-1.1
On Tue, Feb 28, 2023 at 2:55 PM James Knott via talk <talk@gtalug.org> wrote:
Doesn't the PPP server normally provide the DNS address? https://www.rfc-editor.org/rfc/rfc1877.html#section-1.1
I'd have expected so, but that RFC says "By default, no primary DNS address is provided." thanks
On 2023-02-28 14:58, Stewart Russell via talk wrote:
On Tue, Feb 28, 2023 at 2:55 PM James Knott via talk <talk@gtalug.org> wrote:
> Doesn't the PPP server normally provide the DNS address? https://www.rfc-editor.org/rfc/rfc1877.html#section-1.1
I'd have expected so, but that RFC says "By default, no primary DNS address is provided."
Can you reach hosts by IP address? PPP does not work the same way as a LAN does. On a LAN, DNS would normally be provided by the DHCP server. However, since PPP links provide the IP address, no DHCP server is used. Also, I believe there's a slightly different DNS provided for Windows clients. How is that network set up? Perhaps for Windows clients and you're using Linux?
I wonder if 1. they decided to not use DNS, in which case they would have given you an IP address, or 2. they decided to not tell outsiders where the DNS server was, so that the outsider would have to be given an IP address, or 3. they didn't tell outsiders where the DNS server was because they didn't know they needed to, and just took the default (;-)) --dave On 2/28/23 14:58, Stewart Russell via talk wrote: On Tue, Feb 28, 2023 at 2:55 PM James Knott via talk <talk@gtalug.org<mailto:talk@gtalug.org>> wrote:
Doesn't the PPP server normally provide the DNS address? https://www.rfc-editor.org/rfc/rfc1877.html#section-1.1 I'd have expected so, but that RFC says "By default, no primary DNS address is provided." thanks --- Post to this mailing list talk@gtalug.org<mailto:talk@gtalug.org> Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest dave.collier-brown@indexexchange.com<mailto:dave.collier-brown@indexexchange.com> | -- Mark Twain CONFIDENTIALITY NOTICE AND DISCLAIMER : This telecommunication, including any and all attachments, contains confidential information intended only for the person(s) to whom it is addressed. Any dissemination, distribution, copying or disclosure is strictly prohibited and is not a waiver of confidentiality. If you have received this telecommunication in error, please notify the sender immediately by return electronic mail and delete the message from your inbox and deleted items folders. This telecommunication does not constitute an express or implied agreement to conduct transactions by electronic means, nor does it constitute a contract offer, a contract amendment or an acceptance of a contract offer. Contract terms contained in this telecommunication are subject to legal review and the completion of formal documentation and are not binding until same is confirmed in writing and has been signed by an authorized signatory.
How do they want you to find things on their net? Do they have a DNS server? Surely yes. They should put it into the PPP negotiation. Why would they not? If they won't put it into PPP, maybe you have to monkey with /etc/resolv.conf (systemd will argue with you). If they don't have a DNS, what do they use? Perhaps you can use mDNS / bonjour / whatever? Does the device have another internet connection at the same time? At other times? If so, it might need a DNS solution that works for that connection.
PPP does not require a dns server address to be provided. But most folks do provide one because it would make for LOTS of support calls to not hand out your DNS servers. Is there a DNS on the network that your connecting to at all? If not then you wll likely be forecd to use the /etc/hosts file to add in the IP addresses of the target systems. On 2023-02-28 14:50, Stewart Russell via talk wrote:
Hey - we've got a fun little problem happening right now.
We're connecting a Linux box via LTE to a client's private network. They want us to connect to a host on that network and upload files via sftp. We've demonstrated that all of this works with every other LTE network, but in their walled garden LTE network, they're not returning any DNS server, so we can't find the host at all. This network does not have access to public DNS.
Does one usually have to poke a ppp connection a little more to get useful routing information, or should we have "just got" all the gateway and DNS details on first connection?
Stewart (as you can tell, I'm not a network person, but we might appreciate finding one and paying for support)
--- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- Alvin Starr || land: (647)478-6285 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net ||
Thanks, all. Yes, there has to be a DNS, but there's a chance that 1. we haven't been told what it is; 2. our connection/hardware hasn't been authorized to connect to it or know what it is (yes, it's that kind of place) There is no other internet connection. We've been given a host name, not an internal IP address to connect to. We're also hearing that we're the first folks connecting via this ultra-locked down LTE network for IOT devices, so maybe they forgot to provision some services On Tue, Feb 28, 2023 at 3:11 PM Alvin Starr via talk <talk@gtalug.org> wrote:
PPP does not require a dns server address to be provided. But most folks do provide one because it would make for LOTS of support calls to not hand out your DNS servers.
Is there a DNS on the network that your connecting to at all? If not then you wll likely be forecd to use the /etc/hosts file to add in the IP addresses of the target systems.
On 2023-02-28 14:50, Stewart Russell via talk wrote:
Hey - we've got a fun little problem happening right now.
We're connecting a Linux box via LTE to a client's private network. They want us to connect to a host on that network and upload files via sftp. We've demonstrated that all of this works with every other LTE network, but in their walled garden LTE network, they're not returning any DNS server, so we can't find the host at all. This network does not have access to public DNS.
Does one usually have to poke a ppp connection a little more to get useful routing information, or should we have "just got" all the gateway and DNS details on first connection?
Stewart (as you can tell, I'm not a network person, but we might appreciate finding one and paying for support)
--- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- Alvin Starr || land: (647)478-6285 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net ||
--- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- http://scruss.com/blog/ - 73 de VA3PID
You can enable debugging in your pppd config which may help. There is also a "usepeerdns" pppd option that may give you some joy. I have a client who has a prison as a customer and they have lots of unusual requirements for computers inside the wire. I have debugged hundreds of PPP clients/servers over the years so if you want some help feel free to reach out and contact me. On 2023-02-28 15:28, Stewart Russell via talk wrote:
Thanks, all. Yes, there has to be a DNS, but there's a chance that
1. we haven't been told what it is; 2. our connection/hardware hasn't been authorized to connect to it or know what it is (yes, it's that kind of place)
There is no other internet connection. We've been given a host name, not an internal IP address to connect to. We're also hearing that we're the first folks connecting via this ultra-locked down LTE network for IOT devices, so maybe they forgot to provision some services
On Tue, Feb 28, 2023 at 3:11 PM Alvin Starr via talk <talk@gtalug.org> wrote:
PPP does not require a dns server address to be provided. But most folks do provide one because it would make for LOTS of support calls to not hand out your DNS servers.
Is there a DNS on the network that your connecting to at all? If not then you wll likely be forecd to use the /etc/hosts file to add in the IP addresses of the target systems.
On 2023-02-28 14:50, Stewart Russell via talk wrote: > Hey - we've got a fun little problem happening right now. > > We're connecting a Linux box via LTE to a client's private network. > They want us to connect to a host on that network and upload files via > sftp. We've demonstrated that all of this works with every other LTE > network, but in their walled garden LTE network, they're not returning > any DNS server, so we can't find the host at all. This network does > not have access to public DNS. > > Does one usually have to poke a ppp connection a little more to get > useful routing information, or should we have "just got" all the > gateway and DNS details on first connection? > > Stewart > (as you can tell, I'm not a network person, but we might appreciate > finding one and paying for support) > > > --- > Post to this mailing list talk@gtalug.org > Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- Alvin Starr || land: (647)478-6285 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net ||
--- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- http://scruss.com/blog/ - 73 de VA3PID
--- Post to this mailing listtalk@gtalug.org Unsubscribe from this mailing listhttps://gtalug.org/mailman/listinfo/talk
-- Alvin Starr || land: (647)478-6285 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net ||
If the externally-reachable network is intended for the IOT devices to connect to, they may well be using IP addresses only. Call it the "DMZ network" or "external network". They probably have a "management network" that goes to different interfaces, and which has DNS services for their own convenience. I've seen setups like this internet --> DMZ network --> host <- management network <- firewall <- office network --dave On 2/28/23 15:28, Stewart Russell via talk wrote: Thanks, all. Yes, there has to be a DNS, but there's a chance that 1. we haven't been told what it is; 2. our connection/hardware hasn't been authorized to connect to it or know what it is (yes, it's that kind of place) There is no other internet connection. We've been given a host name, not an internal IP address to connect to. We're also hearing that we're the first folks connecting via this ultra-locked down LTE network for IOT devices, so maybe they forgot to provision some services On Tue, Feb 28, 2023 at 3:11 PM Alvin Starr via talk <talk@gtalug.org<mailto:talk@gtalug.org>> wrote: PPP does not require a dns server address to be provided. But most folks do provide one because it would make for LOTS of support calls to not hand out your DNS servers. Is there a DNS on the network that your connecting to at all? If not then you wll likely be forecd to use the /etc/hosts file to add in the IP addresses of the target systems. On 2023-02-28 14:50, Stewart Russell via talk wrote:
Hey - we've got a fun little problem happening right now.
We're connecting a Linux box via LTE to a client's private network. They want us to connect to a host on that network and upload files via sftp. We've demonstrated that all of this works with every other LTE network, but in their walled garden LTE network, they're not returning any DNS server, so we can't find the host at all. This network does not have access to public DNS.
Does one usually have to poke a ppp connection a little more to get useful routing information, or should we have "just got" all the gateway and DNS details on first connection?
Stewart (as you can tell, I'm not a network person, but we might appreciate finding one and paying for support)
--- Post to this mailing list talk@gtalug.org<mailto:talk@gtalug.org> Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
-- Alvin Starr || land: (647)478-6285 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net<mailto:alvin@netvel.net> || --- Post to this mailing list talk@gtalug.org<mailto:talk@gtalug.org> Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk -- http://scruss.com/blog/ - 73 de VA3PID --- Post to this mailing list talk@gtalug.org<mailto:talk@gtalug.org> Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest dave.collier-brown@indexexchange.com<mailto:dave.collier-brown@indexexchange.com> | -- Mark Twain CONFIDENTIALITY NOTICE AND DISCLAIMER : This telecommunication, including any and all attachments, contains confidential information intended only for the person(s) to whom it is addressed. Any dissemination, distribution, copying or disclosure is strictly prohibited and is not a waiver of confidentiality. If you have received this telecommunication in error, please notify the sender immediately by return electronic mail and delete the message from your inbox and deleted items folders. This telecommunication does not constitute an express or implied agreement to conduct transactions by electronic means, nor does it constitute a contract offer, a contract amendment or an acceptance of a contract offer. Contract terms contained in this telecommunication are subject to legal review and the completion of formal documentation and are not binding until same is confirmed in writing and has been signed by an authorized signatory.
Ah, they want you to debug for them for free. If the client is big enough, then, yes, do complimentary service. If not, then just upload an encrypted zipfile to OneDrive (or whatever), and tell them to download. On 2023-02-28 15:28, Stewart Russell via talk wrote:
Thanks, all. Yes, there has to be a DNS, but there's a chance that
1. we haven't been told what it is; 2. our connection/hardware hasn't been authorized to connect to it or know what it is (yes, it's that kind of place)
There is no other internet connection. We've been given a host name, not an internal IP address to connect to. We're also hearing that we're the first folks connecting via this ultra-locked down LTE network for IOT devices, so maybe they forgot to provision some services
On Tue, Feb 28, 2023 at 3:11 PM Alvin Starr via talk <talk@gtalug.org <mailto:talk@gtalug.org>> wrote:
PPP does not require a dns server address to be provided. But most folks do provide one because it would make for LOTS of support calls to not hand out your DNS servers.
Is there a DNS on the network that your connecting to at all? If not then you wll likely be forecd to use the /etc/hosts file to add in the IP addresses of the target systems.
On 2023-02-28 14:50, Stewart Russell via talk wrote: > Hey - we've got a fun little problem happening right now. > > We're connecting a Linux box via LTE to a client's private network. > They want us to connect to a host on that network and upload files via > sftp. We've demonstrated that all of this works with every other LTE > network, but in their walled garden LTE network, they're not returning > any DNS server, so we can't find the host at all. This network does > not have access to public DNS. > > Does one usually have to poke a ppp connection a little more to get > useful routing information, or should we have "just got" all the > gateway and DNS details on first connection? > > Stewart > (as you can tell, I'm not a network person, but we might appreciate > finding one and paying for support) > > > --- > Post to this mailing list talk@gtalug.org <mailto:talk@gtalug.org> > Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk <https://gtalug.org/mailman/listinfo/talk>
-- Alvin Starr || land: (647)478-6285 Netvel Inc. || Cell: (416)806-0133 alvin@netvel.net <mailto:alvin@netvel.net> ||
--- Post to this mailing list talk@gtalug.org <mailto:talk@gtalug.org> Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk <https://gtalug.org/mailman/listinfo/talk>
-- http://scruss.com/blog/ <http://scruss.com/blog/> - 73 de VA3PID
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On Tue, Feb 28, 2023 at 4:13 PM William Park via talk <talk@gtalug.org> wrote:
Ah, they want you to debug for them for free.
This is absolutely not the case. Never attribute to malice that which can be more easily explained by massive bureaucracy. Also, these are devices that are on a network that couldn't reach OneDrive. Stewart
On 28/02/2023 16.22, James Knott via talk wrote:
On 2023-02-28 16:21, Stewart Russell via talk wrote:
Also, these are devices that are on a network that couldn't reach OneDrive.
Maybe you could try sneakernet. 😉 They're in sealed boxes, up high, possibly near high-voltage equipment. You go first, I'll wait ...
I don't do dialup anymore. But, looking at my old PPP setup (I'm surprised I still have it), 'dns-addr' is assigned in /etc/ppp/options. On 2023-02-28 14:50, Stewart Russell via talk wrote:
Hey - we've got a fun little problem happening right now.
We're connecting a Linux box via LTE to a client's private network. They want us to connect to a host on that network and upload files via sftp. We've demonstrated that all of this works with every other LTE network, but in their walled garden LTE network, they're not returning any DNS server, so we can't find the host at all. This network does not have access to public DNS.
Does one usually have to poke a ppp connection a little more to get useful routing information, or should we have "just got" all the gateway and DNS details on first connection?
Stewart (as you can tell, I'm not a network person, but we might appreciate finding one and paying for support)
--- Post to this mailing list talk@gtalug.org Unsubscribe from this mailing list https://gtalug.org/mailman/listinfo/talk
On Wed, Mar 1, 2023 at 1:08 AM William Park via talk <talk@gtalug.org> wrote:
I don't do dialup anymore. But, looking at my old PPP setup (I'm surprised I still have it), 'dns-addr' is assigned in /etc/ppp/options.
Yeah, there's a lot going on in ppp systems. I was slightly surprised how the old scripts I used for dialup over 20 years (and a different country) ago were still used for LTE modem connections, complete with an even larger set of AT commands to control the device. I still think of AT commands as "Hayes" commands, even though Hayes themselves haven't existed this century. (Dennis Hayes still exists personally, as far as I know, as does his business partner Dale Heatherington - who retired at age 37 in the mid 80s, and seems to have had a great time since then.) I guess ppp will be with us forever. I was pretty impressed that someone managed to implement a ppp wifi modem on the very cheap ESP8266 microcontroller. If you have a serial port, you can now talk (not very fast) over wifi: https://www.tindie.com/products/theoldnet/rs232-serial-wifi-modem-for-vintag... (there's a github link to the source in there for folks who might build their own) Stewart
On 2023-03-01 13:24, Stewart Russell via talk wrote:
I was slightly surprised how the old scripts I used for dialup over 20 years (and a different country) ago were still used for LTE modem connections, complete with an even larger set of AT commands to control the device. I still think of AT commands as "Hayes" commands, even though Hayes themselves haven't existed this century. (Dennis Hayes still exists personally, as far as I know, as does his business partner Dale Heatherington - who retired at age 37 in the mid 80s, and seems to have had a great time since then.)
Years ago, I had a Nokia 2G phone (the old Rogers IS-136 network, before they switched to GSM) which could use the AT commands to act as a modem. I never used it, as that was an extra cost service.
I guess ppp will be with us forever. I was pretty impressed that someone managed to implement a ppp wifi modem on the very cheap ESP8266 microcontroller. If you have a serial port, you can now talk (not very fast) over wifi: https://www.tindie.com/products/theoldnet/rs232-serial-wifi-modem-for-vintag... (there's a github link to the source in there for folks who might build their own)
PPP is used in PPPoE, as in ADSL internet connections. PPP is an official RFC spec and used in many places you never heard of. For example with routers, you could use PPP over a T1 line. You'd configure it in the CSU. It's also covered in the Cisco CCNA. If you want to get into the gritty details, you can read "Using & Managing PPP", from O'Reilly. It's just a method of providing a layer 2 network over a serial connection. BTW, when I got my first Internet connection (anyone remember io.org?), I used a SLIP connection, which was popular before PPP was commonly used. SLIP required a static config, as it didn't provide connection info, as PPP does.
participants (7)
-
Alvin Starr -
D. Hugh Redelmeier -
Dave Collier-Brown -
James Knott -
Stewart C. Russell -
Stewart Russell
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William Park