Reverse or inverse ARP from windows/linux - no way (!?!?)
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From: Didi on 29 Mar 2010 05:19 On Mar 29, 7:37 am, "JosephKK"<quiettechb...(a)yahoo.com> wrote: > On Sun, 28 Mar 2010 19:07:27 -0700 (PDT), Didi <d...(a)tgi-sci.com> wrote: > >On Mar 29, 4:00 am, "markp" <map.nos...(a)f2s.com> wrote: > >> > I think I got to the bottom of it - why this is impossible under > >> > windows, that is. > >> > I had posted the same question in a local (Bulgarian) forum, and today > >> > a guy replied and posted this pointer: > >> > http://en.wikipedia.org/wiki/Raw_socket > > >> Raw sockets is the ability to bypass the encapsulation of the lower level > >> OS. All you need to do is send a legitimate UDP broadcast 'enquire' packet > >> and receive uni-cast replies, I can't see why you would want to create your > >> own raw packets and why you can't just use the OS to encapsulate your data > >> normally (?) > > >> Mark. > > >So how do you send an ARP packet via UDP? (FYI: ARP is lower level > >than UDP). > > >Dimiter > > APR lower level than UDP? I don't think so. Same level at best, below UDP > is MAC and PHY only. Uhm, not so sure. Same level as UDP in that they both have the Ethernet protocol type set to "internet", perhaps; but the data inside a UDP packet are encapsulated into that level, whereas the ARP data are purely Ethernet encapsulated. This should put it one level lower - at least unofficially? Dimiter
From: Didi on 29 Mar 2010 05:26 On Mar 29, 5:23 am, "markp" <map.nos...(a)f2s.com> wrote: > "Didi" <d...(a)tgi-sci.com> wrote in message > > news:c89e214e-efb8-43f5-b877-be5dc44378ee(a)i25g2000yqm.googlegroups.com... > On Mar 29, 4:00 am, "markp" <map.nos...(a)f2s.com> wrote: > > > > > > I think I got to the bottom of it - why this is impossible under > > > windows, that is. > > > I had posted the same question in a local (Bulgarian) forum, and today > > > a guy replied and posted this pointer: > > >http://en.wikipedia.org/wiki/Raw_socket > > >> Raw sockets is the ability to bypass the encapsulation of the lower level > >> OS. All you need to do is send a legitimate UDP broadcast 'enquire' > >> packet > >> and receive uni-cast replies, I can't see why you would want to create > >> your > >> own raw packets and why you can't just use the OS to encapsulate your > >> data > >> normally (?) > > >> Mark. > > So how do you send an ARP packet via UDP? (FYI: ARP is lower level > >than UDP). > > Dimiter > > I may have got this wrong, but I thought you wanted to find the address of a > newly connected web-server on a local network and be able to configure a > browser to access it. No no, you are correct on that. I was just looking for some readily available utility, I avoid wintel programming like the plague, just the thought of their APIs etc. stuff makes me sick. > In which case all that is needed is to do is run a > small utility on the browser PC that sends a UDP broadcast packet, the data > portion of which contains the PC's IP address. That "angry IP scanner" I found is doing something similar (uses ICMP echo) and does the job for small networks. For large ones it will be less practical to manually dig through a huge list, though... Dimiter
From: Didi on 29 Mar 2010 05:31 On Mar 29, 12:19 pm, Didi <d...(a)tgi-sci.com> wrote: > On Mar 29, 7:37 am, "JosephKK"<quiettechb...(a)yahoo.com> wrote: > > > > > On Sun, 28 Mar 2010 19:07:27 -0700 (PDT), Didi <d...(a)tgi-sci.com> wrote: > > >On Mar 29, 4:00 am, "markp" <map.nos...(a)f2s.com> wrote: > > >> > I think I got to the bottom of it - why this is impossible under > > >> > windows, that is. > > >> > I had posted the same question in a local (Bulgarian) forum, and today > > >> > a guy replied and posted this pointer: > > >> > http://en.wikipedia.org/wiki/Raw_socket > > > >> Raw sockets is the ability to bypass the encapsulation of the lower level > > >> OS. All you need to do is send a legitimate UDP broadcast 'enquire' packet > > >> and receive uni-cast replies, I can't see why you would want to create your > > >> own raw packets and why you can't just use the OS to encapsulate your data > > >> normally (?) > > > >> Mark. > > > >So how do you send an ARP packet via UDP? (FYI: ARP is lower level > > >than UDP). > > > >Dimiter > > > APR lower level than UDP? I don't think so. Same level at best, below UDP > > is MAC and PHY only. > > Uhm, not so sure. Same level as UDP in that they both have the > Ethernet > protocol type set to "internet", perhaps; but the data inside a UDP > packet > are encapsulated into that level, whereas the ARP data are purely > Ethernet > encapsulated. This should put it one level lower - at least > unofficially? > > Dimiter Or may be I forgot that, $806 was ARP and $800 was internet so may be they are officially different - Oh no, I may be dealing with their hex dumps and I may have implemented them but I really would not argue about the official side of things :-) . I know my stack handles the ARP packets at the same level as IP packets, UDP is one level "higher". Dimiter
From: markp on 29 Mar 2010 06:53 <snip> >> I may have got this wrong, but I thought you wanted to find the address >> of a >> newly connected web-server on a local network and be able to configure a >> browser to access it. > No no, you are correct on that. I was just looking for some readily >available utility, I avoid wintel programming like the plague, just >the thought of their APIs etc. stuff makes me sick. >> In which case all that is needed is to do is run a >> small utility on the browser PC that sends a UDP broadcast packet, the >> data >> portion of which contains the PC's IP address. >That "angry IP scanner" I found is doing something similar (uses ICMP >echo) and does the job for small networks. For large ones it will be >less practical to manually dig through a huge list, though... >Dimiter Ahha, you're after some already existing software to map MAC addresses to IP addresses. If you open a command box in XP and type 'arp -a' you get a list of MAC addresses and their associated IP addresses. Is that what you want? you could easily write a batch file to scan for a given MAC address or dump to a file to search. Mark.
From: glen herrmannsfeldt on 29 Mar 2010 11:10
In comp.protocols.tcp-ip markp <map.nospam(a)f2s.com> wrote: (snip, someone wrote) >> No no, you are correct on that. I was just looking for some readily >>available utility, I avoid wintel programming like the plague, just >>the thought of their APIs etc. stuff makes me sick. (snip) > Ahha, you're after some already existing software to map MAC > addresses to IP addresses. > If you open a command box in XP and type 'arp -a' you get a list of MAC > addresses and their associated IP addresses. Is that what you want? you > could easily write a batch file to scan for a given MAC address or dump to a > file to search. Some will respond to a ping to the broadcast address, others not. It seems that it you want to be found then you should respond. Then you can ping to the broadcast address, followed by arp -a to see who replied. -- glen |