Hi There:
I recently moved my main Linux box from Ubuntu 22.04 LTS to 24.04 LTS. Prior to that I have been using tcpser quite successfully to connect to it via telnet.
However, once I moved to 24.04 LTS, tcpser no longer worked. If I did "ATDTlocalhost" I would just get the connect message and nothing else.
I looked into what changed and it looks like Ubuntu has decided to start using inetutils-telnetd instead of the "netkit telnetd." Something about inetutils-telnetd is incompatible with tcpser.
It is possible to move back to the "netkit telnetd" and tcpser will work as before.
The inetutils-telnetd appears to come from: https://www.gnu.org/software/inetutils/
The inetutils telnetd gives a much more verbose login information that it doesn't appear you can turn off. It looks like this when you use a standard telnet client:
Connected to 192.168.1.145.
Escape character is '^]'.
Linux 6.18.7-76061807-generic (omega.localdomain) (pts/9)
omega login:
The netkit-telnet appears to come from here:
https://github.com/marado/netkit-telnet/tree/master
This gives a more traditional output:
Connected to localhost.
Escape character is '^]'.
Ubuntu 24.04.4 LTS
omega login:
I don't know if there is any more protocol negotiation that the inetutils version is doing, but tcpser does not appear to work with it.
Hi There:
I recently moved my main Linux box from Ubuntu 22.04 LTS to 24.04 LTS. Prior to that I have been using tcpser quite successfully to connect to it via telnet.
However, once I moved to 24.04 LTS, tcpser no longer worked. If I did "ATDTlocalhost" I would just get the connect message and nothing else.
I looked into what changed and it looks like Ubuntu has decided to start using inetutils-telnetd instead of the "netkit telnetd." Something about inetutils-telnetd is incompatible with tcpser.
It is possible to move back to the "netkit telnetd" and tcpser will work as before.
The inetutils-telnetd appears to come from: https://www.gnu.org/software/inetutils/
The inetutils telnetd gives a much more verbose login information that it doesn't appear you can turn off. It looks like this when you use a standard telnet client:
Connected to 192.168.1.145.
Escape character is '^]'.
Linux 6.18.7-76061807-generic (omega.localdomain) (pts/9)
omega login:
The netkit-telnet appears to come from here:
https://github.com/marado/netkit-telnet/tree/master
This gives a more traditional output:
Connected to localhost.
Escape character is '^]'.
Ubuntu 24.04.4 LTS
omega login:
I don't know if there is any more protocol negotiation that the inetutils version is doing, but tcpser does not appear to work with it.