telnetd vs telnetd -a


 
Thread Tools Search this Thread
Special Forums Cybersecurity telnetd vs telnetd -a
# 1  
Old 07-21-2006
telnetd vs telnetd -a

Hi folks. I have a quick question on using "telnetd" vs. "telnetd -a".

OS: AIX 5.x (5.1 through 5.3 ML3)

Some engineers at work want to stop using "telnetd -a" and use "telnetd".
(and of course, if I could get a cogent answer from them, I wouldn't be posting this question...) Smilie

The man page for telnetd suggests that "telnetd -a" offers improved performance as follows:

-a Causes the PTY and socket to be linked directly in the kernel so that the data handling remains in the kernel to improve the performance.

I don't see a security issue here, so I'm guessing that there might be a memory issue related to this.

Barring a call to IBM (which I'm about to make), does anyone have a quick answer as to why *not* to use -a, or which option is preferred? Smilie

Thanks!

-Dave
Login or Register to Ask a Question

Previous Thread | Next Thread

8 More Discussions You Might Find Interesting

1. AIX

telnetd daemon

Hi, When a client connected to AIX server by telnet is killed/crashes, is there a way for telnetd to recognize that and close/kill the application linked/started by that telnet session? We have a situation where clients disconnect because of frequent network outages, this leaves the... (2 Replies)
Discussion started by: mreyaz
2 Replies

2. SCO

Telnetd Port Options

Ok, here i am in 2008 trying to figure out how to edit the port of Telnetd in sco openserver 4.2. I googled my butt off and cant seem to find any info. Does anyone have some specific howto's or good documentation on this? (2 Replies)
Discussion started by: j0ntar
2 Replies

3. Solaris

Can't start telnetd

Hello all, I've got a problem on a V240 running Solaris 9, the telnet daemon won't start. The error message I get is "telnetd: stdin is not a socket file descriptor." I've never seen this message before and I'm not exactly sure what it means. I know generally what stdin, sockets, and file... (4 Replies)
Discussion started by: ONEX
4 Replies

4. Solaris

telnetd bug!

hi mates, a very important info for all solaris admins, there is a bug in telnetd on nearly every solaris version: pressy@mp-wst01 # id uid=100(pressy) gid=1(other) pressy@mp-wst01 # telnet -l "-froot" 192.168.40.1 Trying 192.168.40.1... Connected to 192.168.40.1. Escape character is... (3 Replies)
Discussion started by: pressy
3 Replies

5. UNIX for Dummies Questions & Answers

telnetd: all network ports in use

I hope someone can enlighten me on this. A few weeks ago, the root file system my UnixWare 7.1.1 server became corrupt so I ended up doing a full restore of the OS from tape backup. Since then, after I get about 270 users on the system, the message "telnetd: all network ports in use" is... (1 Reply)
Discussion started by: davekox
1 Replies

6. UNIX for Dummies Questions & Answers

Get telnetd to start a process other than login

I want to be able to get telnetd to start a program of my choice or one that I have written . . . or . . . write a daemon of my own to listen on a port other than 23 and when a connection arrives it should create a controlling tty/pty and then launch my program on the client side of the pty. A... (2 Replies)
Discussion started by: pdenaro
2 Replies

7. IP Networking

in.telnetd[5115] -- compromised?

/* Linux Slackware */ looking in my logs I see tons of entries similar to below. Does anyone know what these mean, and should I be concerned. I looked up a few of the IP's at Arin.net and saw that many of them belong to isp's (not good).. Any information is helpful.. Body of Messages log... (1 Reply)
Discussion started by: LowOrderBit
1 Replies

8. UNIX for Dummies Questions & Answers

Linux and in.telnetd problems

Hi, This is not the usual "unable to telnet to my machine" post. I: * have ensured that in.telnetd is started from inet.conf * that hosts.allow/deny are correctly configured * in.telnetd is listening, and on the correct port When I check my syslog i notice that tcpd (as I have... (3 Replies)
Discussion started by: sam_pointer
3 Replies
Login or Register to Ask a Question
telnetd(8c)															       telnetd(8c)

Name
       telnetd - DARPA TELNET protocol server

Syntax
       /etc/telnetd

Description
       The  server  supports the DARPA standard TELNET virtual terminal protocol.  The TELNET server is invoked when receives a connection request
       on the port indicated in the TELNET service description.

       The server operates by allocating a pseudo-terminal device for a client, then creating a login process which has  the  slave  side  of  the
       pseudo-terminal	as stdin, stdout, and stderr.  The server manipulates the master side of the pseudo terminal, implementing the TELNET pro-
       tocol and passing characters between the client and login process.

       When a TELNET session is started up, sends a TELNET option to the client side indicating a willingness to do remote echo of characters,	to
       suppress  go  ahead, and to receive terminal type information from the remote client.  If the remote client is willing, the remote terminal
       type is propagated in the environment of the created login process.  The pseudo terminal allocated to the client is configured  to  operate
       in cooked mode and with XTABS and CRMOD enabled.

       Aside  from  this  initial  setup, the only mode changes will carry out are those required for echoing characters at the client side of the
       connection.

       The server supports binary mode, suppress go ahead, echo, and timing mark.  It also allows a remote client to do binary, terminal type, and
       suppress go ahead.

Restrictions
       Some TELNET commands are only partially implemented.

       The TELNET protocol allows the exchange of the number of lines and columns on the user's terminal, but does not make use of them.

       The terminal type name received from the remote client is converted to lower case.

       The server never sends TELNET go ahead commands.

See Also
       telnet(1c), pty(4), tty(4), services(5), inetd(8c)

																       telnetd(8c)