Remote target behind console server

Remote target behind console server

[KONG, Gangfeng]

Hi,

I have a target sitting behind a console server. I can use any box to
telnet to the console server and access the console port of my target. This 
target
runs Linux kgdb stub on it. I have tested with serial cable, for my gdb host to
debug the kgdb target, everything is perfect. But in our situation, we must 
debug
our target remotely through console server.

The question is whether it's feasible for gdb to remote debug this target 
through
console server, which is a telnet / serial converter?

Thanks
GF

Re: Remote target behind console server

[Andrew Cagney]

> Hi,
> 
> I have a target sitting behind a console server. I can use any box to
> telnet to the console server and access the console port of my target. This target
> runs Linux kgdb stub on it. I have tested with serial cable, for my gdb host to
> debug the kgdb target, everything is perfect. But in our situation, we must debug
> our target remotely through console server.
> 
> The question is whether it's feasible for gdb to remote debug this target through
> console server, which is a telnet / serial converter?

You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so 
that  the terminal server automatically connects the GDB session through 
to the serial port.  There isn't an easy way, from GDB, to send terminal 
server commands.

enjoy,
Andrew

Re: Remote target behind console server

[Quality Quorum]

On Fri, 28 Jun 2002, Andrew Cagney wrote:

> > Hi,
> >
> > I have a target sitting behind a console server. I can use any box to
> > telnet to the console server and access the console port of my target. This target
> > runs Linux kgdb stub on it. I have tested with serial cable, for my gdb host to
> > debug the kgdb target, everything is perfect. But in our situation, we must debug
> > our target remotely through console server.
> >
> > The question is whether it's feasible for gdb to remote debug this target through
> > console server, which is a telnet / serial converter?
>
> You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so
> that  the terminal server automatically connects the GDB session through
> to the serial port.  There isn't an easy way, from GDB, to send terminal
> server commands.

You have to configure your terminal server appropriately (either enable
'raw' mode on the terminal server or disable 'X' command on the stub/gdb)
and this is basically it, people do it all the time.

If you are going to do 'load' over this connection big terminal server
buffers may screw it up.

>
> enjoy,
> Andrew
>
>

Thanks,

Aleksey

Re: Remote target behind console server

[KONG, Gangfeng]

>
> >
> > You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so
> > that  the terminal server automatically connects the GDB session through
> > to the serial port.  There isn't an easy way, from GDB, to send terminal
> > server commands.
>
>You have to configure your terminal server appropriately (either enable
>'raw' mode on the terminal server or disable 'X' command on the stub/gdb)
>and this is basically it, people do it all the time.
>
>If you are going to do 'load' over this connection big terminal server
>buffers may screw it up.
Thanks for your message,

Basically I need to use 'telnet' to the ip-addr of my terminal server to access
the serial port of my target box. I may reconfigure the terminal server, but
how can I let gdb to setup an telnet connection to the terminal server and
then take this connection as media for its serial access to the stub on
the target?

Thanks
GF.

Re: Remote target behind console server

[Daniel Jacobowitz]

On Fri, Jun 28, 2002 at 06:45:17PM -0700, KONG, Gangfeng wrote:
> 
> >
> >>
> >> You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so
> >> that  the terminal server automatically connects the GDB session through
> >> to the serial port.  There isn't an easy way, from GDB, to send terminal
> >> server commands.
> >
> >You have to configure your terminal server appropriately (either enable
> >'raw' mode on the terminal server or disable 'X' command on the stub/gdb)
> >and this is basically it, people do it all the time.
> >
> >If you are going to do 'load' over this connection big terminal server
> >buffers may screw it up.
> Thanks for your message,
> 
> Basically I need to use 'telnet' to the ip-addr of my terminal server to 
> access
> the serial port of my target box. I may reconfigure the terminal server, but
> how can I let gdb to setup an telnet connection to the terminal server and
> then take this connection as media for its serial access to the stub on
> the target?

Have you tried using 'target remote ip-addr:port' to the terminal
server directly?

-- 
Daniel Jacobowitz                           Carnegie Mellon University
MontaVista Software                         Debian GNU/Linux Developer

Re: Remote target behind console server

[Quality Quorum]

On Fri, 28 Jun 2002, KONG, Gangfeng wrote:

>
> >
> > >
> > > You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so
> > > that  the terminal server automatically connects the GDB session through
> > > to the serial port.  There isn't an easy way, from GDB, to send terminal
> > > server commands.
> >
> >You have to configure your terminal server appropriately (either enable
> >'raw' mode on the terminal server or disable 'X' command on the stub/gdb)
> >and this is basically it, people do it all the time.
> >
> >If you are going to do 'load' over this connection big terminal server
> >buffers may screw it up.
> Thanks for your message,
>
> Basically I need to use 'telnet' to the ip-addr of my terminal server to access
> the serial port of my target box. I may reconfigure the terminal server, but
> how can I let gdb to setup an telnet connection to the terminal server and
> then take this connection as media for its serial access to the stub on
> the target?

target remote host:port

I do not have gdb on the system I am typing, but I hope the syntax is
correct

>
> Thanks
> GF.
>

Thanks,

Aleksey

Re: Remote target behind console server

[KONG, Gangfeng]

At 12:28 AM 6/29/2002 -0400, Daniel Jacobowitz wrote:
>On Fri, Jun 28, 2002 at 06:45:17PM -0700, KONG, Gangfeng wrote:
> >
> > >
> > >>
> > >> You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so
> > >> that  the terminal server automatically connects the GDB session through
> > >> to the serial port.  There isn't an easy way, from GDB, to send terminal
> > >> server commands.
> > >
> > >You have to configure your terminal server appropriately (either enable
> > >'raw' mode on the terminal server or disable 'X' command on the stub/gdb)
> > >and this is basically it, people do it all the time.
> > >
> > >If you are going to do 'load' over this connection big terminal server
> > >buffers may screw it up.
> > Thanks for your message,
> >
> > Basically I need to use 'telnet' to the ip-addr of my terminal server to
> > access
> > the serial port of my target box. I may reconfigure the terminal 
> server, but
> > how can I let gdb to setup an telnet connection to the terminal server and
> > then take this connection as media for its serial access to the stub on
> > the target?
>
>Have you tried using 'target remote ip-addr:port' to the terminal
>server directly?


Hi,

I start the gdb stub on the target by:
         gdbstart -s 38400 -t /dev/ttyS0
and start the gdb on the development box by:
         gdb vmlinux
         gdb)
         gdb) set remotebaud 38400
         gdb) target remote my-server-ipaddr:port  #note, the port I put 
here is the serial port# on the server,
                                                 #not L4 port, correct?
Now I only get error message:
         ignoring packet error, continuing....

If I replace the console server by a direct serial cable for the above 2 
boxes,
and use 'target remote /dev/ttyS0' instead. Everything works fine. So I know
except the serial connection, the rest configs are correct.

Could anybody correct me where I did wrongly ?

Thanks
GF

Re: Remote target behind console server

[Quality Quorum]

On Tue, 2 Jul 2002, KONG, Gangfeng wrote:

> At 12:28 AM 6/29/2002 -0400, Daniel Jacobowitz wrote:
> >On Fri, Jun 28, 2002 at 06:45:17PM -0700, KONG, Gangfeng wrote:
> > >
> > > >
> > > >>
> > > >> You mean an ``annex[tm]''?  Yes.  You'll likely need to tweak things so
> > > >> that  the terminal server automatically connects the GDB session through
> > > >> to the serial port.  There isn't an easy way, from GDB, to send terminal
> > > >> server commands.
> > > >
> > > >You have to configure your terminal server appropriately (either enable
> > > >'raw' mode on the terminal server or disable 'X' command on the stub/gdb)
> > > >and this is basically it, people do it all the time.
> > > >
> > > >If you are going to do 'load' over this connection big terminal server
> > > >buffers may screw it up.
> > > Thanks for your message,
> > >
> > > Basically I need to use 'telnet' to the ip-addr of my terminal server to
> > > access
> > > the serial port of my target box. I may reconfigure the terminal
> > server, but
> > > how can I let gdb to setup an telnet connection to the terminal server and
> > > then take this connection as media for its serial access to the stub on
> > > the target?
> >
> >Have you tried using 'target remote ip-addr:port' to the terminal
> >server directly?
>
>
> Hi,
>
> I start the gdb stub on the target by:
>          gdbstart -s 38400 -t /dev/ttyS0
> and start the gdb on the development box by:
>          gdb vmlinux
>          gdb)
>          gdb) set remotebaud 38400
>          gdb) target remote my-server-ipaddr:port  #note, the port I put
> here is the serial port# on the server,
>                                                  #not L4 port, correct?

No, you have to use telnet port here.


> Now I only get error message:
>          ignoring packet error, continuing....
>
> If I replace the console server by a direct serial cable for the above 2
> boxes,
> and use 'target remote /dev/ttyS0' instead. Everything works fine. So I know
> except the serial connection, the rest configs are correct.
>
> Could anybody correct me where I did wrongly ?
>
> Thanks
> GF
>
>
Thanks,

Aleksey

Re: Remote target behind console server

[Andrew Cagney]

> I start the gdb stub on the target by:
>         gdbstart -s 38400 -t /dev/ttyS0
> and start the gdb on the development box by:
>         gdb vmlinux
>         gdb)
>         gdb) set remotebaud 38400

Just BTW, since it is TCP, setting the remote baud won't have any effect.

Suggest adding a:

(gdb) set debug remote 1

here.  It will cause GDB to print all remote traffic and that will 
hopefully make it easier to see why things are going wrong.  You should 
be able to compare it to a working direct connection.

>         gdb) target remote my-server-ipaddr:port  #note, the port I put here is the serial port# on the server,
>  

enjoy,
Andrew

Re: Remote target behind console server

[KONG, Gangfeng]

At 11:40 AM 7/3/2002 -0400, Andrew Cagney wrote:
>>I start the gdb stub on the target by:
>>         gdbstart -s 38400 -t /dev/ttyS0
>>and start the gdb on the development box by:
>>         gdb vmlinux
>>         gdb)
>>         gdb) set remotebaud 38400
>
>Just BTW, since it is TCP, setting the remote baud won't have any effect.
>
>Suggest adding a:
>
>(gdb) set debug remote 1
>
>here.  It will cause GDB to print all remote traffic and that will 
>hopefully make it easier to see why things are going wrong.  You should be 
>able to compare it to a working direct connection.

Hi,

I attached the output from my development box after I 'set debug remote 1'.
It looks like it didn't get reponse from target box. I have no idea......

--------------------------------------------------
(gdb) set debug remote 1
(gdb) target remote 4.22.79.12:2001
Remote debugging using 4.22.79.12:2001
Sending packet: $Hc-1#09...putpkt: Junk: {{}?s!t
Packet instead of Ack, ignoring it
Timeout in mid-packet, retrying
Sending packet: $Hc-1#09...putpkt: Junk: s!u
H 1!st
|
Sending packet: $Hc-1#09...putpkt: Junk: s!u
H 1!st
|
Sending packet: $Hc-1#09...putpkt: Junk: s!u
H 1!su
x
Timed out.
Timed out.
Timed out.
Ignoring packet error, continuing...
Sending packet: $qC#b4...putpkt: Junk: s!uD ss_}!u
H 1!st
Sending packet: $qC#b4...putpkt: Junk: s v1!ubs}
Sending packet: $qC#b4...putpkt: Junk: s!vYmubs}
Sending packet: $qC#b4...putpkt: Junk: s!ub 1!sv
Timed out.
Timed out.
Timed out.
Ignoring packet error, continuing...
Sending packet: $qOffsets#4b...putpkt: Junk: s!u! ssW}!u
b 1!u
b 1!su
Sending packet: $qOffsets#4b...putpkt: Junk: s!ub 1!u
Sending packet: $qOffsets#4b...putpkt: Junk: s*vb 1!u
Sending packet: $qOffsets#4b...putpkt: Junk: s!ub 1!u
Timed out.
Timed out.
Timed out.
Ignoring packet error, continuing...
Couldn't establish connection to remote target
Malformed response to offset query, timeout
(gdb)

Re: Remote target behind console server

[KONG, Gangfeng]

> >
> > Hi,
> >
> > I start the gdb stub on the target by:
> >          gdbstart -s 38400 -t /dev/ttyS0
> > and start the gdb on the development box by:
> >          gdb vmlinux
> >          gdb)
> >          gdb) set remotebaud 38400
> >          gdb) target remote my-server-ipaddr:port  #note, the port I put
> > here is the serial port# on the server,
> >                                                  #not L4 port, correct?
>
>No, you have to use telnet port here.

Hi,

normally, I use the command:
         telent server-ipaddr 2001
to access its port 1. (2002 for port 2, 2003 for port 3 ...)

It looks like console server already map its L4 port into serial port.

Thanks
GF

Re: Remote target behind console server

[Quality Quorum]

On Wed, 3 Jul 2002, KONG, Gangfeng wrote:

>
> > >
> > > Hi,
> > >
> > > I start the gdb stub on the target by:
> > >          gdbstart -s 38400 -t /dev/ttyS0
> > > and start the gdb on the development box by:
> > >          gdb vmlinux
> > >          gdb)
> > >          gdb) set remotebaud 38400
> > >          gdb) target remote my-server-ipaddr:port  #note, the port I put
> > > here is the serial port# on the server,
> > >                                                  #not L4 port, correct?
> >
> >No, you have to use telnet port here.
>
> Hi,
>
> normally, I use the command:
>          telent server-ipaddr 2001
> to access its port 1. (2002 for port 2, 2003 for port 3 ...)
>
> It looks like console server already map its L4 port into serial port.

I suppose that L4 means port 4 on the server and /dev/ttyS0 on the target
then you have to use 'target server-ipaddr 2004'.


If L4 means something else, then use another port.


How to debug a connection:

1. Make sure that terminal server is properly configured and the
   cable is good:  connect port 4 on the terminal server to the some known
   working target, e.g. standar UNIX serial port, do 'telnet server-ip
   2004' and type stuff on console and check responses.

2. Make sure that gdb stub is workin properly: connect port 4 on the
   terminal server to debug port on the targe, start gdb stub, again do
   'telnet server-ip 2004' and make sure that by hitting return you
   cause gdb to send you properly formed packets.

3. Start gdb and do 'target remote server-ip:2004' I would be very
   surprised if it does not work at the point.

>
> Thanks
> GF
>

Thanks,

Aleksey

Re: Remote target behind console server

[Eli Zaretskii]

On Thu, 4 Jul 2002, Quality Quorum wrote:

> On Wed, 3 Jul 2002, KONG, Gangfeng wrote:
> 
> > > > I start the gdb stub on the target by:
> > > >          gdbstart -s 38400 -t /dev/ttyS0
> > > > and start the gdb on the development box by:
> > > >          gdb vmlinux
> > > >          gdb)
> > > >          gdb) set remotebaud 38400
> > > >          gdb) target remote my-server-ipaddr:port  #note, the port I put
> > > > here is the serial port# on the server,
> > > >                                                  #not L4 port, correct?
> > >
> > >No, you have to use telnet port here.
> >
> > Hi,
> >
> > normally, I use the command:
> >          telent server-ipaddr 2001
> > to access its port 1. (2002 for port 2, 2003 for port 3 ...)
> >
> > It looks like console server already map its L4 port into serial port.
> 
> I suppose that L4 means port 4 on the server and /dev/ttyS0 on the target
> then you have to use 'target server-ipaddr 2004'.
> 
> 
> If L4 means something else, then use another port.
> 
> 
> How to debug a connection:
> 
> 1. Make sure that terminal server is properly configured and the
>    cable is good:  connect port 4 on the terminal server to the some known
>    working target, e.g. standar UNIX serial port, do 'telnet server-ip
>    2004' and type stuff on console and check responses.
> 
> 2. Make sure that gdb stub is workin properly: connect port 4 on the
>    terminal server to debug port on the targe, start gdb stub, again do
>    'telnet server-ip 2004' and make sure that by hitting return you
>    cause gdb to send you properly formed packets.
> 
> 3. Start gdb and do 'target remote server-ip:2004' I would be very
>    surprised if it does not work at the point.

Does anyone think that some of the above should be in the manual?

Re: Remote target behind console server

[KONG, Gangfeng]

At 12:33 AM 7/4/2002 -0400, Quality Quorum wrote:


>On Wed, 3 Jul 2002, KONG, Gangfeng wrote:
>
> >
> > > >
> > > > Hi,
> > > >
> > > > I start the gdb stub on the target by:
> > > >          gdbstart -s 38400 -t /dev/ttyS0
> > > > and start the gdb on the development box by:
> > > >          gdb vmlinux
> > > >          gdb)
> > > >          gdb) set remotebaud 38400
> > > >          gdb) target remote my-server-ipaddr:port  #note, the port 
> I put
> > > > here is the serial port# on the server,
> > > >                                                  #not L4 port, correct?
> > >
> > >No, you have to use telnet port here.
> >
> > Hi,
> >
> > normally, I use the command:
> >          telent server-ipaddr 2001
> > to access its port 1. (2002 for port 2, 2003 for port 3 ...)
> >
> > It looks like console server already map its L4 port into serial port.
>
>I suppose that L4 means port 4 on the server and /dev/ttyS0 on the target
>then you have to use 'target server-ipaddr 2004'.

In fact, L4 port, I mean Layer 4 (transport layer) port. Sorry for the 
confusion.
I am very sure I was assigned at port 1. And I use 'telnet server-ipaddr 2001'
to access the target console normally.,



>If L4 means something else, then use another port.
>
>
>How to debug a connection:
>
>1. Make sure that terminal server is properly configured and the
>    cable is good:  connect port 4 on the terminal server to the some known
>    working target, e.g. standar UNIX serial port, do 'telnet server-ip
>    2004' and type stuff on console and check responses.
>
>2. Make sure that gdb stub is workin properly: connect port 4 on the
>    terminal server to debug port on the targe, start gdb stub, again do
>    'telnet server-ip 2004' and make sure that by hitting return you
>    cause gdb to send you properly formed packets.
>
>3. Start gdb and do 'target remote server-ip:2004' I would be very
>    surprised if it does not work at the point.
>

In order to check the whole system, I did install a kgdb stub of linux on my
laptop, so that I can move it around. What I have done are:
1. enable the /dev/ttyS0 in /etc/inittab, then I can login through serial port
     the check whether it works. I connect it to the port 1 of my console 
server,
     then, I remotely login into it by 'telnet server-ipaddr 2001'. Works!
     SO:
         - target serial port works
         - console server works
2. I move the laptop target close to my development box, and I use serial cable
     to connect them directly. I start the stub on target by 'gdbstart -s 
38400 -t
     /dev/ttyS0'. And then start the gdb on the development box. Now I can use
     gdb to debug my target box as expected.
     SO:
         - the stub on target is ok
         - the gdb on the development box is ok
3. Now I move the laptop target back to the console server and connect the port
     1 to its serial port and start the stub by 'gdbstart -s 38400 -t 
/dev/ttyS0', and
     go the development box to start the gdb and try to access the target 
box by
     'target remote server-ipaddr:2001'.
     But it fails......

I don't know what's wrong.

Thanks
GF

Re: Remote target behind console server

[Quality Quorum]

On Thu, 4 Jul 2002, KONG, Gangfeng wrote:

> At 12:33 AM 7/4/2002 -0400, Quality Quorum wrote:
>
>
> >On Wed, 3 Jul 2002, KONG, Gangfeng wrote:
> >
> > >
> > > > >
> > > > > Hi,
> > > > >
> > > > > I start the gdb stub on the target by:
> > > > >          gdbstart -s 38400 -t /dev/ttyS0
> > > > > and start the gdb on the development box by:
> > > > >          gdb vmlinux
> > > > >          gdb)
> > > > >          gdb) set remotebaud 38400
> > > > >          gdb) target remote my-server-ipaddr:port  #note, the port
> > I put
> > > > > here is the serial port# on the server,
> > > > >                                                  #not L4 port, correct?
> > > >
> > > >No, you have to use telnet port here.
> > >
> > > Hi,
> > >
> > > normally, I use the command:
> > >          telent server-ipaddr 2001
> > > to access its port 1. (2002 for port 2, 2003 for port 3 ...)
> > >
> > > It looks like console server already map its L4 port into serial port.
> >
> >I suppose that L4 means port 4 on the server and /dev/ttyS0 on the target
> >then you have to use 'target server-ipaddr 2004'.
>
> In fact, L4 port, I mean Layer 4 (transport layer) port. Sorry for the
> confusion.
> I am very sure I was assigned at port 1. And I use 'telnet server-ipaddr 2001'
> to access the target console normally.,
>
>
>
> >If L4 means something else, then use another port.
> >
> >
> >How to debug a connection:
> >
> >1. Make sure that terminal server is properly configured and the
> >    cable is good:  connect port 4 on the terminal server to the some known
> >    working target, e.g. standar UNIX serial port, do 'telnet server-ip
> >    2004' and type stuff on console and check responses.
> >
> >2. Make sure that gdb stub is workin properly: connect port 4 on the
> >    terminal server to debug port on the targe, start gdb stub, again do
> >    'telnet server-ip 2004' and make sure that by hitting return you
> >    cause gdb to send you properly formed packets.
> >
> >3. Start gdb and do 'target remote server-ip:2004' I would be very
> >    surprised if it does not work at the point.
> >
>
> In order to check the whole system, I did install a kgdb stub of linux on my
> laptop, so that I can move it around. What I have done are:
> 1. enable the /dev/ttyS0 in /etc/inittab, then I can login through serial port
>      the check whether it works. I connect it to the port 1 of my console
> server,
>      then, I remotely login into it by 'telnet server-ipaddr 2001'. Works!
>      SO:
>          - target serial port works
>          - console server works
> 2. I move the laptop target close to my development box, and I use serial cable
>      to connect them directly. I start the stub on target by 'gdbstart -s
> 38400 -t
>      /dev/ttyS0'. And then start the gdb on the development box. Now I can use
>      gdb to debug my target box as expected.
>      SO:
>          - the stub on target is ok
>          - the gdb on the development box is ok


I suppose that you are using null-modem cable at the point.


> 3. Now I move the laptop target back to the console server and connect the port
>      1 to its serial port and start the stub by 'gdbstart -s 38400 -t
> /dev/ttyS0', and
>      go the development box to start the gdb and try to access the target
> box by
>      'target remote server-ipaddr:2001'.
>      But it fails......
>
> I don't know what's wrong.

I suppose port configuration or wrong cable or wrong baud rate, I
suppose you have to use stright cable here and in many cases authobaud
feature does not work with gdb stub.

Anyway, connect you rtarget to the terminal server, start gdb stub, do
'telnet serverip 2001' and try to figure out what is going wrong until
you see '$...#yy in response to pressing ENTER.


>
> Thanks
> GF
>
>

Thanks,

Aleksey

Re: Remote target behind console server

[KONG, Gangfeng]

>
> >
> > In order to check the whole system, I did install a kgdb stub of linux 
> on my
> > laptop, so that I can move it around. What I have done are:
> > 1. enable the /dev/ttyS0 in /etc/inittab, then I can login through 
> serial port
> >      the check whether it works. I connect it to the port 1 of my console
> > server,
> >      then, I remotely login into it by 'telnet server-ipaddr 2001'. Works!
> >      SO:
> >          - target serial port works
> >          - console server works
> > 2. I move the laptop target close to my development box, and I use 
> serial cable
> >      to connect them directly. I start the stub on target by 'gdbstart -s
> > 38400 -t
> >      /dev/ttyS0'. And then start the gdb on the development box. Now I 
> can use
> >      gdb to debug my target box as expected.
> >      SO:
> >          - the stub on target is ok
> >          - the gdb on the development box is ok
>
>
>I suppose that you are using null-modem cable at the point.

Yes.



> > 3. Now I move the laptop target back to the console server and connect 
> the port
> >      1 to its serial port and start the stub by 'gdbstart -s 38400 -t
> > /dev/ttyS0', and
> >      go the development box to start the gdb and try to access the target
> > box by
> >      'target remote server-ipaddr:2001'.
> >      But it fails......
> >
> > I don't know what's wrong.
>
>I suppose port configuration or wrong cable or wrong baud rate, I
>suppose you have to use stright cable here and in many cases authobaud
>feature does not work with gdb stub.
>
>Anyway, connect you rtarget to the terminal server, start gdb stub, do
>'telnet serverip 2001' and try to figure out what is going wrong until
>you see '$...#yy in response to pressing ENTER.

Hi,

You are definitely right. The baudrate is wrong, the console server seems not
to be able to auto-configure the baudrate of its ports. I use your suggestion
'telnet serverip 2001' to talk to every possible baudrate of the target from
9600 to 115200. I can not get '$...#yy' reply in any baudrate. But 9600 set 
did give
a me persistent reply '$s05#b8', all of the other baudrate set gave me a series
of changing replies. Late I tried 'target remote serverip:2001' with a 9600 
baudrate
stub. I works!

Thank you very much for your help, I understand it better now!
GF

Re: Remote target behind console server

[Quality Quorum]

>
> You are definitely right. The baudrate is wrong, the console server seems not
> to be able to auto-configure the baudrate of its ports. I use your suggestion
> 'telnet serverip 2001' to talk to every possible baudrate of the target from
> 9600 to 115200. I can not get '$...#yy' reply in any baudrate. But 9600 set
> did give
> a me persistent reply '$s05#b8', all of the other baudrate set gave me a series
> of changing replies. Late I tried 'target remote serverip:2001' with a 9600
> baudrate
> stub. I works!
>
> Thank you very much for your help, I understand it better now!
> GF
>
>

You are welcome, it may be a good idea to reconfigure the port on the
server and disable autobaud.

Thanks,

Aleksey

Re: Remote target behind console server

[Andrew Cagney]

> If L4 means something else, then use another port.
>> 
>> 
>> How to debug a connection:
>> 
>> 1. Make sure that terminal server is properly configured and the
>>    cable is good:  connect port 4 on the terminal server to the some known
>>    working target, e.g. standar UNIX serial port, do 'telnet server-ip
>>    2004' and type stuff on console and check responses.
>> 
>> 2. Make sure that gdb stub is workin properly: connect port 4 on the
>>    terminal server to debug port on the targe, start gdb stub, again do
>>    'telnet server-ip 2004' and make sure that by hitting return you
>>    cause gdb to send you properly formed packets.
>> 
>> 3. Start gdb and do 'target remote server-ip:2004' I would be very
>>    surprised if it does not work at the point.
> 
> 
> Does anyone think that some of the above should be in the manual?

Yes!