• Telnet issues for SBBS

    From Dmxrob@1:103/705 to All on Wed Feb 6 19:52:13 2019
    OS: CentOS 7
    Firewall: Port 23 open

    I have an issue with SBBS and allowing telnet logins. It appears that I can access it just fine if I SSH to the box and then "telnet localhost" but if I try from another PC on the network I get a connection refused message. I believe
    it may have to do with something regarding ipv6 and ipv4. I noticed when I telnet to localhost it fails on the ipv4 address, then works on the ipv6 address.

    The log files contain this, which isn't really telling me much...

    Feb 06 19:47:56 bbs synchronet[6132]: term 0052 !ERROR 95 setting socket option (TCP_NODELAY, 1) to 1
    Feb 06 19:47:56 bbs synchronet[6132]: term Node 1 local spy using socket localspy1.sock
    Feb 06 19:47:56 bbs synchronet[6132]: term 0053 !ERROR 95 setting socket option (TCP_NODELAY, 1) to 1
    Feb 06 19:47:56 bbs synchronet[6132]: term Node 2 local spy using socket localspy2.sock
    Feb 06 19:47:56 bbs synchronet[6132]: term 0054 !ERROR 95 setting socket option (TCP_NODELAY, 1) to 1
    Feb 06 19:47:56 bbs synchronet[6132]: term Node 3 local spy using socket localspy3.sock
    Feb 06 19:47:56 bbs synchronet[6132]: term 0055 !ERROR 95 setting socket option (TCP_NODELAY, 1) to 1
    Feb 06 19:47:56 bbs synchronet[6132]: term Node 4 local spy using socket localspy4.sock
    Feb 06 19:47:56 bbs synchronet[6132]: term Terminal Server thread started for nodes 1 through 4
    Feb 06 19:47:56 bbs synchronet[6132]: evnt BBS Events thread started

    Firewall is confirmed that port 23 is open.

    Any help appreciated!

    Rob

    dmxrob - St. Louis, Missouri

    ---
    þ Synchronet þ Gateway to the West - St. Louis, Missouri - bbs.dmxrob.net
    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)
  • From Digital Man@1:103/705 to Dmxrob on Wed Feb 6 17:57:39 2019
    Re: Telnet issues for SBBS
    By: Dmxrob to All on Wed Feb 06 2019 07:52 pm

    OS: CentOS 7
    Firewall: Port 23 open

    I have an issue with SBBS and allowing telnet logins. It appears that I
    can
    access it just fine if I SSH to the box and then "telnet localhost" but if try from another PC on the network I get a connection refused message. I believe
    it may have to do with something regarding ipv6 and ipv4. I noticed when I telnet to localhost it fails on the ipv4 address, then works on the ipv6 address.

    So... telnetting to 127.0.0.1 fails?

    What interfaces do you have the telnet server configured to listen on?

    The log files contain this, which isn't really telling me much...

    Feb 06 19:47:56 bbs synchronet[6132]: term 0052 !ERROR 95 setting socket option (TCP_NODELAY, 1) to 1

    This has been fixed already (and unrelated to your telnet issue): http://cvs.synchro.net/commitlog.ssjs#37683

    Firewall is confirmed that port 23 is open.

    Is sbbs successfully binding to and listening on port 23?

    digital man

    Synchronet "Real Fact" #37:
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    Norco, CA WX: 48.1øF, 45.0% humidity, 0 mph NW wind, 0.00 inches rain/24hrs
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    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)
  • From Dmxrob@1:103/705 to Digital Man on Thu Feb 7 09:54:08 2019
    Re: Telnet issues for SBBS
    By: Digital Man to Dmxrob on Wed Feb 06 2019 05:57 pm

    So... telnetting to 127.0.0.1 fails?

    What interfaces do you have the telnet server configured to listen on?

    telnet to 127.0.0.1 works, but telnet to bbs (the dns name with the actual IP) fails.

    telnet bbs
    Trying 192.168.86.20...
    telnet: connect to address 192.168.86.20: Connection refused

    Nothing shows up in the SBBS log; and eventually the connection just times out.

    Firewall is confirmed that port 23 is open.

    Is sbbs successfully binding to and listening on port 23?

    Port 23 is open and listening...

    tcp LISTEN 0 128 127.0.0.1:23 *:*


    Rob

    dmxrob - St. Louis, Missouri

    ---
    þ Synchronet þ Gateway to the West - St. Louis, Missouri - bbs.dmxrob.net
    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)
  • From Digital Man@1:103/705 to Dmxrob on Thu Feb 7 09:25:34 2019
    Re: Telnet issues for SBBS
    By: Dmxrob to Digital Man on Thu Feb 07 2019 09:54 am

    Re: Telnet issues for SBBS
    By: Digital Man to Dmxrob on Wed Feb 06 2019 05:57 pm

    So... telnetting to 127.0.0.1 fails?

    What interfaces do you have the telnet server configured to listen on?

    telnet to 127.0.0.1 works, but telnet to bbs (the dns name with the actual IP) fails.

    telnet bbs
    Trying 192.168.86.20...
    telnet: connect to address 192.168.86.20: Connection refused

    Nothing shows up in the SBBS log; and eventually the connection just times out.

    Firewall is confirmed that port 23 is open.

    Is sbbs successfully binding to and listening on port 23?

    Port 23 is open and listening...

    tcp LISTEN 0 128 127.0.0.1:23 *:*

    If that's the *only* addr:port it's listening on, then that explains why connections to your 192.168.* address don't work.

    Try either changing your TelnetInterface (in sbbs.ini) to 0, or add the 192.168.* interface to the list of interfaces for the server to listen on.

    digital man

    Synchronet "Real Fact" #17:
    "Vertrauen" (ver-trow-en) translates to "trust" in German, and was a band name.
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    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)
  • From Dmxrob@1:103/705 to Digital Man on Thu Feb 7 16:23:05 2019
    Re: Telnet issues for SBBS
    By: Digital Man to Dmxrob on Thu Feb 07 2019 09:25 am

    tcp LISTEN 0 128 127.0.0.1:23 *:*

    If that's the *only* addr:port it's listening on, then that explains why connections to your 192.168.* address don't work.

    Try either changing your TelnetInterface (in sbbs.ini) to 0, or add the 192.168.* interface to the list of interfaces for the server to listen on.

    I've verified that it is binding correctly, and have changed it to the correct IP. However, the behaiour is still the same. If from the bbs machine I "telnet bbs" it works, but if I try from any other PC in the network, it does not.
    Other interfaces work just fine -- HTTP, for example.

    I think its odd nothing shows up in the logs or messages. Beginning to wonder if this is a VMware network issue. I'll keep digging.

    Rob

    dmxrob - St. Louis, Missouri

    ---
    þ Synchronet þ Gateway to the West - St. Louis, Missouri - bbs.dmxrob.net
    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)
  • From Dmxrob@1:103/705 to Digital Man on Thu Feb 7 17:01:28 2019
    Re: Telnet issues for SBBS
    By: Dmxrob to Digital Man on Thu Feb 07 2019 04:23 pm

    I think its odd nothing shows up in the logs or messages. Beginning to wonder if this is a VMware network issue. I'll keep digging.

    Turned out it was a firewall issue, though I would have swore I checked those rules a dozen times. I'm writing up some Ansible playbooks to help with this going forward. Once I get them up to Github I'll post a link and share.

    Rob

    dmxrob - St. Louis, Missouri

    ---
    þ Synchronet þ Gateway to the West - St. Louis, Missouri - bbs.dmxrob.net
    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)
  • From Digital Man@1:103/705 to Dmxrob on Thu Feb 7 15:04:41 2019
    Re: Telnet issues for SBBS
    By: Dmxrob to Digital Man on Thu Feb 07 2019 04:23 pm

    Re: Telnet issues for SBBS
    By: Digital Man to Dmxrob on Thu Feb 07 2019 09:25 am

    tcp LISTEN 0 128 127.0.0.1:23 *:*

    If that's the *only* addr:port it's listening on, then that explains why connections to your 192.168.* address don't work.

    Try either changing your TelnetInterface (in sbbs.ini) to 0, or add the 192.168.* interface to the list of interfaces for the server to listen on.

    I've verified that it is binding correctly, and have changed it to the correct IP. However, the behaiour is still the same. If from the bbs machine I "telnet bbs" it works, but if I try from any other PC in the network, it does not.

    Is "bbs" a network-wide recognized hostname? Does it resolve to your public or private IP address?

    Other interfaces work just fine -- HTTP, for example.

    Weird. Maybe if you posted the Interface* lines from your sbbs.ini file, that may provide a clue why that is.

    I think its odd nothing shows up in the logs or messages. Beginning to wonder if this is a VMware network issue. I'll keep digging.

    Okay, let us know what you find out.

    digital man

    Synchronet/BBS Terminology Definition #16:
    DCD = Data Carrier Detect
    Norco, CA WX: 60.8øF, 31.0% humidity, 2 mph WSW wind, 0.00 inches rain/24hrs --- SBBSecho 3.06-Linux
    * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)