RE: [Boston.pm] My IP
On Tue, 30 Dec 2003, Mark Aisenberg wrote: [ cc list trimmed ] 2) dyndns is constantly (monthly or so) emailing me telling me they are under a DoS attack and will be unavailable for a day or so. You've got to decide if you can deal with these hassles. I've also used tzo.com for dynamic DNS. They cost $25/year if I remember correctly, but they seem to be more reliable. Only because they don't inform you when they encounter such issues. I may be biased (well, of course I am, I run DynDNS.org), but I guarantee you TZO and everyone else in this industry have as many or more problems with Denial of Service attacks and the like as we do - they just aren't as up-front and honest about them as we are. It's the two sides of the full-disclosure coin; in a world where not everyone is doing it, those of us who do may not look as good, but at least you know exactly what you're getting, because you can read two years of our system status archives right there on our website, plain and clear in black and white. Tim Wilde -- Tim Wilde [EMAIL PROTECTED] Systems Administrator Dynamic Network Services, Inc. http://www.dyndns.org/ ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm
RE: [Boston.pm] My IP
This may not be news to any of you folks, but recently I was pleased to find out that sshd can listen on more than one port. So on my home router I forward port 22 to box A and port xxx (that I just happen to know is open through my employer's firewall) to box B. sshd on box B listens on ports 22 and xxx. That way I can ssh directly to both from outside, but still just 'ssh hostname' from inside without specifying the port. As for tracking my comcast IP, I'm just too lazy. It's only changed once in about 3 years, and that change was when I got a new modem and the technician had a hard time getting it set up. Some day this will probably bite me but where I live they don't seem to be renumbering any more. Don Silvia -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Uri Guttman Sent: Tuesday, December 30, 2003 2:09 PM To: Joel Gwynn Cc: [EMAIL PROTECTED] Subject: Re: [Boston.pm] My IP JG == Joel Gwynn [EMAIL PROTECTED] writes: JG Hey all. I connect from work via ssh to my home computer, which is JG Comcast broadband. My IP rarely changes, but I'm worried about the one JG day I'm at work and need something from home, and my IP has changed. JG I'm thinking the best thing would be some sort of script that runs every JG hour, and sends me an email if the IP changes. JG Has anyone done anything like this? I'm sure I could whip something up JG in an hour, but I don't want to re-invent the wheel. JG Also, since I'm behind a router, what's the best way to find my IP in JG Perl? asd others have said, dyndns is a good choice. i have a virtual host out there so i rolled my own version of this. i just fetch (with lwp of course) the status page of my nat box and parse out my leased IP address (trivial and in this case it is the first IP on that page). i then ssh it over to my virtual host. from the outside i first login to the virtual host, copy the ip to the laptop or local box, and use that to ssh into my home net. #!/usr/local/bin/perl $link_text = `/usr/local/bin/lwp-request -CNAME:PASSWORD http://192.168.0.100/Status.htm` ; @ips = $link_text =~ /(\d+\.\d+\.\d+\.\d+)/g ; system /bin/echo $ips[2] | /usr/local/bin/ssh -q cell 'cat m1_ip' ; i think 3 lines of perl is considered simple (even if it forks out twice :). this runs under crontab every 15 minutes. i haven't had a problem with it in a long time. note that i don't need a password for the ssh as i put my public (or private, i forget) keys on the virtual host. and a critical thing is to configure your nat box to map the incoming ssh port to the box you want. this can vary depending on the brand and model. one feature (which i wish i had) is that the map can also switch the port number so you could ssh to another port and then be connected to a different box. you could run ssh on a different port on that box and just use the standard map as well. but once you login to a box, you should be able to login to any other box behind your nat. uri -- Uri Guttman -- [EMAIL PROTECTED] http://www.stemsystems.com --Perl Consulting, Stem Development, Systems Architecture, Design and Coding- Search or Offer Perl Jobs http://jobs.perl.org ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm
RE: [Boston.pm] My IP
I use dyndns.org myself for some low-value serving from my home. It works, but I run into two issues with it: 1) my comcast IP address rarely changes, so unless I buy a paid subscription I have to log into my account at dyndns and touch the domain name there to keep it from expiring after 30 days of no changes. 2) dyndns is constantly (monthly or so) emailing me telling me they are under a DoS attack and will be unavailable for a day or so. You've got to decide if you can deal with these hassles. I've also used tzo.com for dynamic DNS. They cost $25/year if I remember correctly, but they seem to be more reliable. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew M. Langmead Sent: Tuesday, December 30, 2003 8:50 AM To: Joel Gwynn Cc: [EMAIL PROTECTED] Subject: Re: [Boston.pm] My IP On Dec 30, 2003, at 8:25 AM, Joel Gwynn wrote: Hey all. I connect from work via ssh to my home computer, which is Comcast broadband. My IP rarely changes, but I'm worried about the one day I'm at work and need something from home, and my IP has changed. Why not use one of those dynamic DNS services like http://www.dyndns.org/ Some appliance routers support sending updates to dyndns when their IP address changes. If you are using some sort of Unix box as the firewall and NAT-ing device, then you could use one of their updating scripts on the firewall itself. To get the non NAT-ed IP address, you either need to fetch the external address from the machine doing that NAT-ing, or have a machine behind the firewall to connect to an external machine and have that external machine call getpeername() on the connection. (for CGI, the results of getpeername() are shown in the REMOTE_ADDR environment variable.) ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm
Re: [Boston.pm] My IP
Dan Boger wrote: On Tue, Dec 30, 2003 at 08:25:43AM -0500, Joel Gwynn wrote: Also, since I'm behind a router, what's the best way to find my IP in Perl? I think your best bet is to set up a CGI someplace external to your network, and have your script hit it. The CGI can then return what IP it sees the query coming from. Assuming he means a NATting router (so his PC is on an RFC1918 network) then surely the best way to query the router for its current configuration is by SNMP or failing that, an Expectish or LWPish script which connects to the router's management port, logs in and tickles it in the right ways. -- David Cantrell | Reality Engineer, Ministry of Information Wow, my first sigquoting! I feel so special now! -- Dan Sugalski ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm
Re: [Boston.pm] My IP
The dynamic dns clients (some aren't free) can be implemented as a very simple perl script, although it's different for each dynamic dns service. I used to use minidns.net because of the ultra-fancy user interface (and it's free) until I moved to britsys.com and got 1500/768 DSL with 5 static IP addresses for $39/month (*plug*). ... $request = new HTTP::Request 'GET', "http://www.minidns.net/areg.php?opcode=ADDusername=yellowbartpassword=eatmyshortshost=lisakissingmilhouse.orgip=$ip"; ... And if you don't specify the ip=$ip, it will use REMOTE_ADDR which is the Internet-visible IP address of the machine running the script. But - you probably don't have to run the script more than once a month. Every hour is overkill (from the original post) and will probably get the Dynamic DNS service admins mad. Chris Devers wrote: On Tue, 30 Dec 2003, David Cantrell wrote: Dan Boger wrote: On Tue, Dec 30, 2003 at 08:25:43AM -0500, Joel Gwynn wrote: Also, since I'm behind a router, what's the best way to find my IP in Perl? I think your best bet is to set up a CGI someplace external to your network, and have your script hit it. The CGI can then return what IP it sees the query coming from. Assuming he means a NATting router (so his PC is on an RFC1918 network) then surely the best way to query the router for its current configuration is by SNMP or failing that, an Expectish or LWPish script which connects to the router's management port, logs in and tickles it in the right ways. Surely that can't be any easier than just using a Dyndns client, no? I mean, the whole point of their service is to do their best to sweep this kind of problem under their nice, plush rug for you. Isn't it worth a try? -- , , , | Duane Bronson /|/|/| , | [EMAIL PROTECTED] ( ( ( |/| | http://www.nerdlogic.com/ \( | | 453 Washington St. #4A, Boston, MA 02111 |/| (617) 515-2909 ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm
RE: [Boston.pm] My IP
Thanks for all the suggestions. For now I'm going the wimpy route, and trying dyndns.org, with the DNSer client service (http://www.access.si/DNSer/DNSer.htm) installed. We'll see how it goes. I have to say, that the 3-line perl solution is tempting. Maybe when I get some free time ... Joel Gwynn Variable Data Spire 617 832-1957 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Uri Guttman Sent: Tuesday, December 30, 2003 2:09 PM To: Joel Gwynn Cc: [EMAIL PROTECTED] Subject: Re: [Boston.pm] My IP JG == Joel Gwynn [EMAIL PROTECTED] writes: JG Hey all. I connect from work via ssh to my home computer, which is JG Comcast broadband. My IP rarely changes, but I'm worried about the one JG day I'm at work and need something from home, and my IP has changed. JG I'm thinking the best thing would be some sort of script that runs every JG hour, and sends me an email if the IP changes. JG Has anyone done anything like this? I'm sure I could whip something up JG in an hour, but I don't want to re-invent the wheel. JG Also, since I'm behind a router, what's the best way to find my IP in JG Perl? asd others have said, dyndns is a good choice. i have a virtual host out there so i rolled my own version of this. i just fetch (with lwp of course) the status page of my nat box and parse out my leased IP address (trivial and in this case it is the first IP on that page). i then ssh it over to my virtual host. from the outside i first login to the virtual host, copy the ip to the laptop or local box, and use that to ssh into my home net. #!/usr/local/bin/perl $link_text = `/usr/local/bin/lwp-request -CNAME:PASSWORD http://192.168.0.100/Status.htm` ; @ips = $link_text =~ /(\d+\.\d+\.\d+\.\d+)/g ; system /bin/echo $ips[2] | /usr/local/bin/ssh -q cell 'cat m1_ip' ; i think 3 lines of perl is considered simple (even if it forks out twice :). this runs under crontab every 15 minutes. i haven't had a problem with it in a long time. note that i don't need a password for the ssh as i put my public (or private, i forget) keys on the virtual host. and a critical thing is to configure your nat box to map the incoming ssh port to the box you want. this can vary depending on the brand and model. one feature (which i wish i had) is that the map can also switch the port number so you could ssh to another port and then be connected to a different box. you could run ssh on a different port on that box and just use the standard map as well. but once you login to a box, you should be able to login to any other box behind your nat. uri -- Uri Guttman -- [EMAIL PROTECTED] http://www.stemsystems.com --Perl Consulting, Stem Development, Systems Architecture, Design and Coding- Search or Offer Perl Jobs http://jobs.perl.org ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm ___ Boston-pm mailing list [EMAIL PROTECTED] http://mail.pm.org/mailman/listinfo/boston-pm
