Well, the original question was getting all the IP addresses a computer posesses.
IMHO I am back to reading the registry information for the TCP Stack :-( Regards Thomas Tomiczek THONA Consulting Ltd. (Microsoft MVP C#/.NET) -----Original Message----- From: Steve Loughran [mailto:[EMAIL PROTECTED]] Sent: Sonntag, 21. April 2002 06:01 To: [EMAIL PROTECTED] Subject: Re: [DOTNET] Finding out the IP-Address of a PC ----- Original Message ----- From: "Thomas Tomiczek" <[EMAIL PROTECTED]> Sent: Friday, April 19, 2002 09:49 Subject: Re: Finding out the IP-Address of a PC >Ok, lets turn this around. >You have computer running an internal NIC, no DNS configured, and an >external one - from your provider. You log into the internet. Ignore all the things like InternetGetConnectedState(), unless they are probing a dialup connection, they are often wrong...they assume no traffic means no net, but on a home lan there often is no traffic. >Will you get both IP addresses using GetHostByName? probably. yes. one will be a made up addr in the 169. range usually, the valid one not. I discard the 169.* addrs; view that as probably invalid. Unless you are on a home network where made up addresses actually work, but I assume home networks have DHCP from somewhere. I also chuck anything all zeros; and favour 10.* and 192.168.* below any other address we have had. > Is actually your.DnsHostName valid? Often never. a) maybe no DNS at all b) system may construct something from the hostname "stelvio" and the domain "attbi.com", come up with a name "stelvio.attbi.com" that doesnt resolve. It has a resolvable name when the machine is at work, but but not at home. You CANNOT trust dns >What about when you are NOT connected to the internet and run this on >one of this automated networks? What do you mean by automated network? One behind a firewall? One completely isolated? Or a VPN. If the thing is on a net, you can probe for remote sites being available. But on some network types, even those that look like a LAN, that can trigger a pay-per-use connection being made, which makes users unhappy. ISDN in the UK, some of the wireless stuff falls into this category. VPNS complicate the mix more. Taking a look at an example config we have Windows IP Configuration Host Name . . . . . . . . . . . . : Stelvio Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Unknown IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No >10/100T, no media, enum does not produce any useful info at all. Ethernet adapter Local Area Connection 2: Media State . . . . . . . . . . . : Media disconnected Description . . . . . . . . . . . : 3Com Megahertz 10/100 LAN CardBus P Card Physical Address. . . . . . . . . : 00-00-86-3A-4B-94 >not a real card, an ipsec device driver. This one will enum when you >list hostnames, you have to discard it when all zero, cos it means it is not there Ethernet adapter {9CF134F9-E3EA-4CE6-9673-60DF7ED4872E}: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Nortel IPSECSHM Adapter - Packet Sc eduler Miniport Physical Address. . . . . . . . . : 44-45-53-54-42-00 Dhcp Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 0.0.0.0 Subnet Mask . . . . . . . . . . . : 0.0.0.0 Default Gateway . . . . . . . . . : >aah, we have a network here Ethernet adapter lucent card: Connection-specific DNS Suffix . : steveshome Description . . . . . . . . . . . : ORiNOCO PC Card (5 volt) Physical Address. . . . . . . . . : 00-02-2D-00-56-51 Dhcp Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 192.168.2.21 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 192.168.2.1 DHCP Server . . . . . . . . . . . : 192.168.2.1 DNS Servers . . . . . . . . . . . : 192.168.2.1 Lease Obtained. . . . . . . . . . : Saturday, April 20, 2002 20:11:08 Lease Expires . . . . . . . . . . : Saturday, May 04, 2002 20:11:08 its in the 192.168 dont route properly domain, but it isnt a 169.* number so is probably ok, just behind a NAT (or two, in this case) But rdns wont work; there are no DNS servers in the subnets, and nothing outside will find it. Or, if it does it will translate to 12.somethingorother, which is the single visible point to the outside world; eiger.dnsalias.com, but the latop knows nothing. FFI, see http://www.iseran.com/Steve/papers.html; Towards an Adaptive and Context Aware Laptop and The Secret Life of Notebooks, You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com. You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
