Hi, Jeff. On Thu, 27 Feb 1997 15:11:19 -0500, Jeff Kell <[log in to unmask]> wrote: |I don't recall the details, and I've searched the archives off and on |all morning with no luck other than a message I had sent in Nov 1995: | |> Hmmm... someone not long ago (Guy Smith?) figured out a way with |> DTC-Manager to telnet to a DTC port and loop a cable over to an |> adjacent port as a quick and dirty way to get telnet access to the |> system. It turns out that I am one of the biggest information pack-rats in the known universe and had both of these messages in my mail folder (along with a bazillion others). I hope this contains the info or pointers you need. Forwarded message: On Thu, 21 Sep 1995 14:14:56 -0400, Jon Diercks <[log in to unmask]> wrote: |Subject: back-to-back DTC ports | |After seeing a message on HPADM that got my mind working, and doing some |digging, I saw that one can telnet to a specific serial port on a DTC, |*without* having a TAC card, by using specific TCP ports numbers mapped to |DTC serial ports. For instance, telnet mydtc.xxx.yyy 1047 will connect to |port 3 on slot 0. From there, I would think I should be able to |back-to-back into another DTC port and thereby connect to my hp3000 - the |end result being a single-port telnet server to the 3k. | |I haven't quite been able to make it work though. Can anybody offer any |tips on how the two DTC ports should be configured in OVDTCMGR for this to |work? I assume the cable connecting the two ports should be cross-wired for |null-modem equivalence, right? Some of my experiments have gotten very |close but failed due to some sort of 'feedback loop' where prompts were |bouncing back upon themselves. | |TIA. | | ----------------------------------------------------------------------- | Jon Diercks -------- mail: [log in to unmask] | Programmer/Analyst /|| | chat: powwow:[log in to unmask] | Computing Services /_|| | WWW : http://rowlf.csv.anderson.edu/ | Anderson University / ||__| tel : (317)641-4305 | Anderson, IN 46012 -------- fax : (317)641-3851 | o________________________________________________________ ___ | _\_, \=`==^==> | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ On Mon, 25 Sep 1995 09:17:33 -0400, Jon Diercks <[log in to unmask]> wrote: |Subject: Re: back-to-back DTC ports | |At 03:35 PM 9/22/95 -0700, Michael Hensley wrote: |>Now, to pay "us" all back for the help, how about writing up the whole solution |>and submitting it for inclusion in the FAQ? You'll be famous! | |Good idea Michael. Here's some notes. Hopefully the FAQ maintainer (Chris |Bartram?) will pick this up. | |Using Back-to-Back DTC ports to permit inbound telnet without a TAC |=================================================================== | |With OpenView DTC Manager, a DTC port can be configured as one of three |types - terminal, printer, or host. If configured as a host port, the port |can be accessed via telnet to the DTC's IP address at a specific TCP port |number, as calculated by the following formula (taken from HPSL document |N2X94121300C |(http://support.mayfield.hp.com/kdb-bin/wwwsdoc.pl?DOCID=N2X94121300C)): | |( ( ( 32 * dtc_board_number ) + dtc_port + 1 ) * 256 ) + 23 | |So, for example, for a dtc at IP address 199.8.123.123 to connect to port 2 |on board 0 you would use "telnet 199.8.123.123 791". | |Once this port is accessible via telnet, if it is cabled to another DTC port |which is configured as a normal terminal, then the incoming telnet can be |passed serially to a DTC> prompt, or if switching is not enabled, pass |directly to the default destination for that port. If the destination is an |MPE/iX system, then we have effectively translated from telnet to rs232 to |AFCP, providing a means for a user with telnet but not NS/VT capability to |access the MPE/iX system from the network, without a Telnet Access Card in |the DTC. | |Miscellaneous supplemental notes: | |The cable connecting the two DTC ports does *not* need to be crossed (i.e. |null-modem). | |Recommend not using speed sensing on either port, but rather just set them |both to 19200bps. | |The serial link between DTC ports is the slowest link in the chain here, so |even if the telnet user has a T1 line, they'll only get 19200bps throughput. | |Only one telnet connection per port at a time. If a second user tries to |connect, they'll appear to get connected but will not receive any prompts. | |Some obvious security concerns are raised by this configuration. NS/VT |provides a certain level of 'security by obscurity', while telnet access is |more widely understood and available. | |Disconnecting from the telnet session is not automatic. Upon logging off |the session will be left at a new logon prompt. Most telnet clients use ^] |to escape back to a telnet> prompt, from which a 'quit' command usually |closes the connection. | | ----------------------------------------------------------------------- | Jon Diercks -------- mail: [log in to unmask] | Programmer/Analyst /|| | chat: powwow:[log in to unmask] | Computing Services /_|| | WWW : http://rowlf.csv.anderson.edu/ | Anderson University / ||__| tel : (317)641-4305 | Anderson, IN 46012 -------- fax : (317)641-3851 | o________________________________________________________ ___ | _\_, \=`==^==> | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -- Jeff Woods [log in to unmask] at Unison Software [log in to unmask] at home [PGP key available here via finger] "Be virtuous and you will be eccentric." -- Mark Twain (1835-1910) P.S. (re: my quote du jour) Hmmm... Does it work the other way around too?