Is there a way to know the ISP with the default installation of Stretch?
My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] before starting browsing or any remote connection... With the 'route' command it was so easy '# route' and goal! With le last release 'Stretch' the net-tools packet is not installed by default. But if this command was so useful, why It was removed? I repeat, I need to know the ISP before to establish any connection!! [I need this because some Italian provider, and are so many, do not allow some services that machines provided... e.g.: VoIP, so I need to know the ISP before so to avoid initializing the machine.] How Can I do with the default installation? Thank for reply.
Re: Is there a way to know the ISP with the default installation of Stretch?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Tue, Jan 02, 2018 at 12:42:35PM +0100, Max Power wrote: > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] > before starting browsing or any remote connection... > With the 'route' command it was so easy '# route' and goal! > With le last release 'Stretch' the net-tools packet is not installed by > default. There *just* was a thread around here: either use ip -r route (-r means try to resolve IP address to name, your old "route" did exactly that), or just install net-tools (as you said above). > But if this command was so useful, why It was removed? Folks, don't get so worked up when your favourite package is not installed by default. Otherwise the default install would end up installing *all* packages! Just go install it. If enough of you do (and enable popcon, hint, hint) it might become again default, who knows? Whining here won't help and just makes the mailing list more annoying. FWIW, I have net-tools installed and use old and new. Happy camper. Cheers - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlpLc6IACgkQBcgs9XrR2kbIHQCdEDMOHSBs74jxEgUzAaAuddSp Z9IAn1xlBdc+5M7UKkhKgdWNiYkWQB8K =RJej -END PGP SIGNATURE-
Re: Is there a way to know the ISP with the default installation of Stretch?
On 2018-01-02, wrote: > > On Tue, Jan 02, 2018 at 12:42:35PM +0100, Max Power wrote: >> My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] >> before starting browsing or any remote connection... >> With the 'route' command it was so easy '# route' and goal! >> With le last release 'Stretch' the net-tools packet is not installed by >> default. > > There *just* was a thread around here: either use ip -r route (-r means > try to resolve IP address to name, your old "route" did exactly that), > or just install net-tools (as you said above). > There just was another thread around here initiated by Max Power, the current OP, I do believe; not liking the answer(s) there or unsatisfied with it(them) for some reason he decided to restart and rephrase (and elucidate and expand in the tradition of obviating the XY problem, though in this case his present Y problem seems to call for the same response as his X did--or vice-versa). -- "An autobiography is only to be trusted when it reveals something disgraceful. A man who gives a good account of himself is probably lying, since any life when viewed from the inside is simply a series of defeats." — George Orwell
Re: Is there a way to know the ISP with the default installation of Stretch?
On Tue, Jan 02, 2018 at 12:42:35PM +0100, Max Power wrote: My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] before starting browsing or any remote connection... With the 'route' command it was so easy '# route' and goal! With le last release 'Stretch' the net-tools packet is not installed by default. But if this command was so useful, why It was removed? I repeat, I need to know the ISP before to establish any connection!! [I need this because some Italian provider, and are so many, do not allow some services that machines provided... e.g.: VoIP, so I need to know the ISP before so to avoid initializing the machine.] How Can I do with the default installation? There isn't an easy way to do that, and there wasn't before. If resolving a non-routable IP happened to work for you previously that was just luck, not something to rely on. The most reliable method would be to use something like https://www.whatismyip.com/ that tells you the public IP you are using to make a connection. Mike Stone
Re: Is there a way to know the ISP with the default installation of Stretch?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Tue, Jan 02, 2018 at 01:05:58PM +, Curt wrote: [...] > There just was another thread around here initiated by Max Power, the > current OP, I do believe [...] Indeed, it was Max (cc'ing him/her just in case). I didn't remember, but checked now. Hi, Max. I don't know what your intentions are in repeating your qualms after two solutions were offered to you. Either get along with the new "ip" or just install the old net-tools. They are not going away (at least not as long as there are people maintaining them, hint, hint). It won't work always (e.g. if your provider doesn't... provide reverse IP lookup *neither* ip -r *nor* route from net-tools will do what you want!). Debian can't declare *every* package as essential: I hope you understand that. Cheers - -- tomás -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlpLjXsACgkQBcgs9XrR2kbXAgCaAuYoyMJ+fCh7aLGTiPPr2D4S cesAoIJFqv+yRWd7gUYh+fvWHFuovT1N =A943 -END PGP SIGNATURE-
Re: Is there a way to know the ISP with the default installation of Stretch?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Max Power wrote: > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] > before starting browsing or any remote connection... Checking the hostname of an RFC1918 address will nearly never provide you with an ISP's name, even if you do it on a residential-gateway device provided by them. -BEGIN PGP SIGNATURE- Version: GnuPG v1 iQEcBAEBAgAGBQJaS602AAoJEI4R3fMSeaKBWC8H/R8L0m81riHdFQ/c3xTKI68O hMbjC4gAJ3uKbfcraAT8QakonR14R+acmFlN4hJW4bAmMDw4lsD+2uv3h2A6vxqR cmn0SIszvcadMlsQSg+87GN4lgT09PpLqdUjSKEJ8aYlGjxqUR42IDv3cf0TjvVa kaH+sNdfz+CyOuknMzUpJORVSCNip0NNaTPIAchvjcLr2BtDHMyGAbwHrT9QEYQk nr9wCJzyXS5eeig/S4iiMvn9NGcx3TIw+UApwDf74tgD7Hhv5uva9P/8IlPCb/sE 36AH9IGPQKHjt4Ooyi/BOXO9oc0AbUALbMUHudjc7lko4ygrhe10df04N2+oZYo= =rF/8 -END PGP SIGNATURE- -- |_|O|_| Registered Linux user #585947 |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281
Re: Is there a way to know the ISP with the default installation of Stretch?
On Tue, Jan 02, 2018 at 04:03:46PM -, Dan Purgert wrote: > Max Power wrote: > > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] > > before starting browsing or any remote connection... > > Checking the hostname of an RFC1918 address will nearly never provide > you with an ISP's name, even if you do it on a residential-gateway > device provided by them. I think the issue here is that he has some sort of unique setup in which this name resolution actually DOES provide meaningful information, much to the surprise of everyone else on the mailing list. Unfortunately, he doesn't realize that this is atypical, so he doesn't know enough to report it to us as part of his question. Also unfortunately, we don't know what he's actually DOING with this name resolution information, so we can't help him. Most particularly, we don't know what the various ISP choices are that he has, what the gateways of those ISPs are, what the name resolutions of those gateways of those ISPs are, or what he wants to do in each of the known, possible cases that he may encounter. THAT is the kind of information we would need in order to help him.
Re: Is there a way to know the ISP with the default installation of Stretch?
On Tue, Jan 02, 2018 at 02:47:39PM +0100, to...@tuxteam.de wrote: Hi, Max. I don't know what your intentions are in repeating your qualms after two solutions were offered to you. Either get along with the new "ip" or just install the old net-tools. They are not going away (at least not as long as there are people maintaining them, hint, hint). As someone who dislikes ip(8), I suspect the eventual solution will be a new, third tool. In the meantime I indeed just install net-tools and get on with my life. -- ⢀⣴⠾⠻⢶⣦⠀ ⣾⠁⢠⠒⠀⣿⡁ Jonathan Dowland ⢿⡄⠘⠷⠚⠋⠀ https://jmtd.net ⠈⠳⣄ Please do not CC me, I am subscribed to the list.
Re: Is there a way to know the ISP with the default installation of Stretch?
Greg Wooledge wrote: > On Tue, Jan 02, 2018 at 04:03:46PM -, Dan Purgert wrote: >> Max Power wrote: >> > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] >> > before starting browsing or any remote connection... >> >> Checking the hostname of an RFC1918 address will nearly never provide >> you with an ISP's name, even if you do it on a residential-gateway >> device provided by them. > > I think the issue here is that he has some sort of unique setup in > which this name resolution actually DOES provide meaningful information, > much to the surprise of everyone else on the mailing list. That's kind of why I was spelling it out in simple terms -- hadn't seen anyone do that yet (or I missed it). Sometimes ends up being the kick people need for their ah-hah moment. -- |_|O|_| Registered Linux user #585947 |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281
Re: Is there a way to know the ISP with the default installation of Stretch?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Tue, Jan 02, 2018 at 04:03:46PM -, Dan Purgert wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > Max Power wrote: > > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] > > before starting browsing or any remote connection... > > Checking the hostname of an RFC1918 address will nearly never provide > you with an ISP's name, even if you do it on a residential-gateway > device provided by them. I think the OP's address was the external address, which very probably *isn't* an RFC1918 (unless his provider puts all of their customers behind a giant NAT: at least on my part of the world this is highly atypical). Cheers - -- t -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlpMkIgACgkQBcgs9XrR2kaYfwCaA2ceXxFjm2efv6hR25DBYu60 hz0An2YCF5YDOeSY9fZ4duxQ97w57ESJ =WCgo -END PGP SIGNATURE-
Re: Is there a way to know the ISP with the default installation of Stretch?
On Tue 02 Jan 2018 at 11:15:16 (-0500), Greg Wooledge wrote: > On Tue, Jan 02, 2018 at 04:03:46PM -, Dan Purgert wrote: > > Max Power wrote: > > > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] > > > before starting browsing or any remote connection... > > > > Checking the hostname of an RFC1918 address will nearly never provide > > you with an ISP's name, even if you do it on a residential-gateway > > device provided by them. > > I think the issue here is that he has some sort of unique setup in > which this name resolution actually DOES provide meaningful information, > much to the surprise of everyone else on the mailing list. > > Unfortunately, he doesn't realize that this is atypical, so he doesn't > know enough to report it to us as part of his question. > > Also unfortunately, we don't know what he's actually DOING with this > name resolution information, so we can't help him. > > Most particularly, we don't know what the various ISP choices are that > he has, what the gateways of those ISPs are, what the name resolutions > of those gateways of those ISPs are, or what he wants to do in each of > the known, possible cases that he may encounter. > > THAT is the kind of information we would need in order to help him. I can only assume that the OP connects through a number of different networks which have been set up with, perhaps, different ranges of IP addresses. For example, and sticking to unroutable addresses, they might be on 192.168.… in one place, 10.… in another etc. I have no idea how you'd find out which ISP is being used, except by making assumptions of this sort, without any connection (assuming "external" connection). The only sugestion I can give to the OP would be to use traceroute (if that wasn't blocked too): $ traceroute -m 4 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 4 hops max, 60 byte packets 1 router (192.168.1.1) 0.958 ms 2.627 ms 6.284 ms 2 10.37.37.1 (10.37.37.1) 45.585 ms 45.544 ms 45.594 ms 3 123.456.789.123 (123.456.789.123) 290.450 ms 290.493 ms 291.698 ms 4 123.456.798.213 (123.456.798.213) 291.702 ms 291.634 ms 291.832 ms $ In my own case, whois on either of the (garbled) addresses above gives the correct ISP, Cox in Atlanta. Had the question been posed a week earlier, I could have tried this from various establishments across four more states. Cheers, David.
Re: Is there a way to know the ISP with the default installation of Stretch?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 wrote: > > On Tue, Jan 02, 2018 at 04:03:46PM -, Dan Purgert wrote: >> -BEGIN PGP SIGNED MESSAGE- >> Hash: SHA1 >> >> Max Power wrote: >> > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] >> > before starting browsing or any remote connection... >> >> Checking the hostname of an RFC1918 address will nearly never provide >> you with an ISP's name, even if you do it on a residential-gateway >> device provided by them. > > I think the OP's address was the external address, which very probably > *isn't* an RFC1918 (unless his provider puts all of their customers > behind a giant NAT: at least on my part of the world this is highly > atypical). It's atypical here too, but that being said, this is a re-hashing of his other thread "hostname of the modem gateway" (thread started with Message-ID: ). - From that post: # route gateway = home.telecomitalia.it # ip route gateway = 192.168.1.1 He was told to use the -r switch in that thread (i.e. `ip -r route') , seems he didn't like the answer and made a new one. -BEGIN PGP SIGNATURE- Version: GnuPG v1 iQEcBAEBAgAGBQJaTMOXAAoJEI4R3fMSeaKB2jMH/0uQc86xjvZuD2cCL/UMuwtv NzwejWF7aPihX/DNT041zpNRdGrSfLsGyDLj9kP/pcygF1+84DdNsVsMj1GYTPSz A6mWv4jHRYvF1AKUpizdIzacYIGxlPIAnzSjaVJ/QV3D93/hNIrYRunOXl5fnt86 i6NQynxLrBxXw+eATZ/2/ILdp0LbBabelPkTazW9+pEu/cv7IO7TWeMwqBkXgjSC AwvVQiOeqAKksZDxriA1bYMz/oq4ErCZUrx/AS5vBwp5QVMn4WTSqAAGCDbYqbqK shGRXymsbRsMdiT3exs3wCW22LmaavDZx9JHPjwjtkTBbNQBuPVVkr8ncAfT0po= =Lc6Q -END PGP SIGNATURE- -- |_|O|_| Registered Linux user #585947 |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281
Re: Is there a way to know the ISP with the default installation of Stretch?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 David Wright wrote: > On Tue 02 Jan 2018 at 11:15:16 (-0500), Greg Wooledge wrote: >> On Tue, Jan 02, 2018 at 04:03:46PM -, Dan Purgert wrote: >> > Max Power wrote: >> > > My problem is to know the ISP [e.g. GATEWAY = Vodafone, Telecom or AT&T] >> > > before starting browsing or any remote connection... >> > >> > Checking the hostname of an RFC1918 address will nearly never provide >> > you with an ISP's name, even if you do it on a residential-gateway >> > device provided by them. >> >> I think the issue here is that he has some sort of unique setup in >> which this name resolution actually DOES provide meaningful information, >> much to the surprise of everyone else on the mailing list. >> >> Unfortunately, he doesn't realize that this is atypical, so he doesn't >> know enough to report it to us as part of his question. >> >> Also unfortunately, we don't know what he's actually DOING with this >> name resolution information, so we can't help him. >> >> Most particularly, we don't know what the various ISP choices are that >> he has, what the gateways of those ISPs are, what the name resolutions >> of those gateways of those ISPs are, or what he wants to do in each of >> the known, possible cases that he may encounter. >> >> THAT is the kind of information we would need in order to help him. > > I can only assume that the OP [...] That's the point :) that's all any of us can do. At the moment, he's already been told how to get "ip" to resolve hostnames (in his other thread -- "ip -r route"), seems he didn't like that answer; and made a new one. -BEGIN PGP SIGNATURE- Version: GnuPG v1 iQEcBAEBAgAGBQJaTNI/AAoJEI4R3fMSeaKBny0IAJc5WMppuzfz84P1n+p83SRY HrgPbe+WFT1pldTJ6LJ8tI05vfXS/qGwYn2HXHBZ8ow8fNB34wTHQa4kMOcBqv2q XKS8G6vsm2708CvK/Ho33E8FUgRadjW1W6D0qQRq/sdaOhFMJl3Grtxyb/pPSZGe U8nkY/fIm925B22UI/DNmh8nDevtP50nZKLJd8QC86JpNOjIsT1BFUqCA/h6E+2z WDU1fUxkvjqJ1P9kLhgcwNKhHSqa/VEw2dvusbJFnaLKkRtqryP0iURPNh2MX1ay YnevBbvlyqsnpirQUiVXaJZUPK+90mfIzs61YIRbHMXG6bbK0rrePVn9kxCeOTw= =NXZv -END PGP SIGNATURE- -- |_|O|_| Registered Linux user #585947 |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: 05CA 9A50 3F2E 1335 4DC5 4AEE 8E11 DDF3 1279 A281
Re: Is there a way to know the ISP with the default installation of Stretch?
On Wednesday, January 03, 2018 07:54:06 AM Dan Purgert wrote: > At the moment, he's already been told how to get "ip" to resolve > hostnames (in his other thread -- "ip -r route"), seems he didn't like > that answer; and made a new one. I hope the OP is still "listening". (And I'm not the OP.) (Extraneous Aside: I think it is strange that "we" talk about the OP instead of talking to him.) Anyway, to the OP (and all): It seems to me (without knowing the OPs complete problem, and based on what I've read in this thread) that traceroute may provide a way forward: * Connect to (any of) your ISP(s). * traceroute somewhere (I'm not sure where atm--maybe some neutral party like google) * Parse the results of the ping to get the numeric address of your ISP * whois that numeric address I think that would give you the ISP's name. Presumably this could be scripted, though I'm not sure how easily--I'm not sure either: * how to (consistently via script) determine which response to the traceroute is from your ISP, although I would guess it is the first non-private (non-RFC1918) address * how to (consistently via script) determine the ISP from the whois This almost works for me--the problem for me is that my ISP is Earthlink which uses / shares the Verizon network, so I find references to Verizon in the whois results, but not Earthlink. PS: I tried to also send this to the OP (Max Power) (because I don't know if he is subscribed to the list) , but I'm not sure I have a valid email address.
Re: Is there a way to know the ISP with the default installation of Stretch?
rhkra...@gmail.com (2018-01-03): > I hope the OP is still "listening". If he is, he is probably enjoying the time wasted by his nonsensical question. Regards, -- Nicolas George signature.asc Description: Digital signature
Re: Is there a way to know the ISP with the default installation of Stretch?
On Wed, Jan 03, 2018 at 10:36:32AM -0500, rhkra...@gmail.com wrote: I've read in this thread) that traceroute may provide a way forward: In general, no. Many ISPs use RFC1918 space internally, so you need to skip an unknown number of hops before you get to a routeable IP, at which point you may or may not find an address that's assigned to the entity providing your internet access (as opposed to whoever is providing their internet access). Mike Stone
Re: Is there a way to know the ISP with the default installation of Stretch?
Le 03/01/2018 à 03:19, David Wright a écrit : For example, and sticking to unroutable addresses, they might be on 192.168.… in one place, 10.… in another etc. Private addresses are routable. They are just not routed over the public internet. Link local addresses (169.254.0.0/16) are not routable.
Re: Is there a way to know the ISP with the default installation of Stretch?
On Wed 03 Jan 2018 at 13:39:14 (-0500), Michael Stone wrote: > On Wed, Jan 03, 2018 at 10:36:32AM -0500, rhkra...@gmail.com wrote: > >I've read in this thread) that traceroute may provide a way forward: > > In general, no. Many ISPs use RFC1918 space internally, so you need > to skip an unknown number of hops before you get to a routeable IP, (In view of https://lists.debian.org/debian-user/2018/01/msg00126.html do you mean public?) > at which point you may or may not find an address that's assigned to > the entity providing your internet access (as opposed to whoever is > providing their internet access). But in that case, would https://www.whatismyip.com/ reveal an address closer to the OP than whoever is providing *their* internet access? (IOW does https://www.whatismyip.com/ ever yield a private address?) My idea of using traceroute (the example illustrated the private address "problem") was not offered to provide a "solution" to the problem, but only to suggest some means by which the OP might decide whether to try using a particular service. But I have no idea why the OP doesn't just try the service to see whether it is supported, rather than playing guessing games in advance. And as I posted earlier, I have no idea where the OP obtained the string home.telecomitalia.it from, and they haven't yet told us. Cheers, David.
Re: Is there a way to know the ISP with the default installation of Stretch?
On Wednesday, January 03, 2018 01:39:14 PM Michael Stone wrote: > On Wed, Jan 03, 2018 at 10:36:32AM -0500, rhkra...@gmail.com wrote: > >I've read in this thread) that traceroute may provide a way forward: > In general, no. Many ISPs use RFC1918 space internally, so you need to > skip an unknown number of hops before you get to a routeable IP, at > which point you may or may not find an address that's assigned to the > entity providing your internet access (as opposed to whoever is > providing their internet access). Ahh, ok, thanks!
Re: Is there a way to know the ISP with the default installation of Stretch?
On Wed, Jan 03, 2018 at 07:04:46PM -0600, David Wright wrote: (In view of https://lists.debian.org/debian-user/2018/01/msg00126.html do you mean public?) No, it's a pretty common shorthand to say "routable" to mean "routable on the public internet", especially where there's no real possibility of confusing it with specifically non-routable blocks like 127.0.0.0/8. Honestly, I considered it less likely to be confusing than calling them RFC1918 addresses in this context. As far as 169.254.0.0/16, it's defined as a link local range for address autoconfiguration, but it can still be routed internally just as much as the RFC1918 space can be. (Doing so just might not be a good idea, because some devices might code in some assumptions or add a zeroconf route by default. Which is annoying because the whole automatic zero knowledge IPv4 autoconfiguration thing is just a spectacularly bad idea anyway that typically causes far more trouble than it's worth. I guess it was useful back in the days when someone might want to connect two win98 machines together to copy a file without using a floppy disk but couldn't think of a reason they might want to use the internet.) IPv6 has an entirely different (and more useful) concept of link local addresses. Some of the other reserved ranges can also be internally routed in practice, so trying to distinguish between "routable" and "non routable" for some meaning other than "not routable on the public internet" rapidly becomes a game of semantics and implementations. But in that case, would https://www.whatismyip.com/ reveal an address closer to the OP than whoever is providing *their* internet access? (IOW does https://www.whatismyip.com/ ever yield a private address?) No, it can't. It will show a public IP that connections from the web client to connect to that particular web site, not a private IP. In the case of a NAT environment there may be multiple different IPs in use, or there may be different IPs for different routes, but there's no reliable way to enumerate every possible IP you might be NATed to. Back to the traceroute idea: it's fairly common for a residential endpoint to have a publically routable IP (usually on the router or "modem") but traceroute won't help identify that--instead, you'll see the private IP that the modem uses to communicate with the machine running traceroute. (In general, traceroute will only show one of many IPs that a particular hop has.) So what you're getting from traceroute isn't going to be the IP you use when communicating with web sites, it's going to be the IP your router uses to communicate with you, then IPs associated with other routers along the way (some of which may also be using RFC1918 space, though it's more common these days for large providers to just pass around encapsulated traffic in a way that's opaque to traceroute, likely over IPv6). In theory another option for finding the public-side gateway IP is UPnP IGD or PCP, but I wouldn't expect those to work on any arbitrary network. Mike Stone
Re: Is there a way to know the ISP with the default installation of Stretch?
Le 04/01/2018 à 05:32, Michael Stone a écrit : No, it's a pretty common shorthand to say "routable" to mean "routable on the public internet", especially where there's no real possibility of confusing it with specifically non-routable blocks like 127.0.0.0/8. This is still a mistake. In technical fields such as this one, words have a well defined meaning. Honestly, I considered it less likely to be confusing than calling them RFC1918 addresses in this context. What about "private", as defined in RFC1918 ? As far as 169.254.0.0/16, it's defined as a link local range for address autoconfiguration, but it can still be routed internally just as much as the RFC1918 space can be. No, unless you're ready to violate the standards. RFC3927 (Dynamic Configuration of IPv4 Link-Local Addresses) explicitly states in chapter 7 "Router Considerations" : A router MUST NOT forward a packet with an IPv4 Link-Local source or destination address, irrespective of the router's default route configuration or routes obtained from dynamic routing protocols. A router which receives a packet with an IPv4 Link-Local source or destination address MUST NOT forward the packet. This prevents forwarding of packets back onto the network segment from which they originated, or to any other segment. Note that it says "MUST", not "SHOULD". (Doing so just might not be a good idea, Yes, violating the standards is often a bad idea. because some devices might code in some assumptions What you call "assumptions" is just compliance with the standards.
