linux-decnet-user — Discussion for users of DECnet on Linux

Re: [Linux-decnet-user] Fwd: Re: DECnet - Malformed Packet: DEC_DNA

[Christine C. <chr...@go...>]

Pavel Pokorný wrote:
> <  ------------ Původní zpráva ------------
> <  Od: Christine Caulfield <chr...@go...>
> <  Předmět: Re: [Linux-decnet-user] Fwd: Re: DECnet - Malformed Packet: DEC_DNA
> <  Datum: 15.7.2008 10:09:48
> <  ----------------------------------------
> <  Pavel Pokorný wrote:
> <  > Hi all,
> <  > 
> <  >    could please anybody confirm or disconfirm me that packets, I have sent to
> <  list, are malformed?
> <  > 
> <  > Thank you.
> <  
> <  Yes, they look truncated to me.
> <  
> <  
> <  -- 
> <  
> <  Chrissie
> <  
> <  -------------------------------------------------------------------------
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> <  Build the coolest Linux based applications with Moblin SDK & win great prizes
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> <  _______________________________________________
> <  Project Home Page: http://linux-decnet.wiki.sourceforge.net/
> <  
> <  Linux-decnet-user mailing list
> <  Lin...@li...
> <  https://lists.sourceforge.net/lists/listinfo/linux-decnet-user
> <  
> <  
> <  
> <  
> 
> Thank you Chrissie. Do you have any idea what could be wrong? dnping has stopped working suddenly. It's interesting when I dnping CentOS itself it works despite malformed packets.

I have no idea, sorry. Steve might, or someone with more low-level Linux 
network knowledge, I've never seen that happen before. I can only assume 
it's happening below the DECnet layer, either in the card driver or the 
card itself perhaps.

It doesn't entirely surprise me that ping TO linux works, VMS is very 
fussy about its packets whereas Linux DECnet is a little more tolerant :)

-- 

Chrissie

Re: [Linux-decnet-user] Fwd: Re: DECnet - Malformed Packet: DEC_DNA

[Pavel P. <Pa...@se...>]

<  ------------ Původní zpráva ------------
<  Od: Christine Caulfield <chr...@go...>
<  Předmět: Re: [Linux-decnet-user] Fwd: Re: DECnet - Malformed Packet: DEC_DNA
<  Datum: 15.7.2008 10:09:48
<  ----------------------------------------
<  Pavel Pokorný wrote:
<  > Hi all,
<  > 
<  >    could please anybody confirm or disconfirm me that packets, I have sent to
<  list, are malformed?
<  > 
<  > Thank you.
<  
<  Yes, they look truncated to me.
<  
<  
<  -- 
<  
<  Chrissie
<  
<  -------------------------------------------------------------------------
<  This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
<  Build the coolest Linux based applications with Moblin SDK & win great prizes
<  Grand prize is a trip for two to an Open Source event anywhere in the world
<  http://moblin-contest.org/redirect.php?banner_id=100&url=/
<  _______________________________________________
<  Project Home Page: http://linux-decnet.wiki.sourceforge.net/
<  
<  Linux-decnet-user mailing list
<  Lin...@li...
<  https://lists.sourceforge.net/lists/listinfo/linux-decnet-user
<  
<  
<  
<  

Thank you Chrissie. Do you have any idea what could be wrong? dnping has stopped working suddenly. It's interesting when I dnping CentOS itself it works despite malformed packets.

Thanks.

Pavel

Re: [Linux-decnet-user] Fwd: Re: DECnet - Malformed Packet: DEC_DNA

[Christine C. <chr...@go...>]

Pavel Pokorný wrote:
> Hi all,
> 
>    could please anybody confirm or disconfirm me that packets, I have sent to list, are malformed?
> 
> Thank you.

Yes, they look truncated to me.


-- 

Chrissie

[Linux-decnet-user] Fwd: Re: DECnet - Malformed Packet: DEC_DNA

[Pavel P. <Pa...@se...>]

Hi all,

   could please anybody confirm or disconfirm me that packets, I have sent to list, are malformed?

Thank you.

Pavel

Re: [Linux-decnet-user] DECnet - Malformed Packet: DEC_DNA

[Pavel P. <Pa...@se...>]

<  ------------ Původní zpráva ------------
<  Od: Steven Whitehouse <st...@ch...>
<  Předmět: Re: [Linux-decnet-user] DECnet - Malformed Packet: DEC_DNA
<  Datum: 14.7.2008 14:08:05
<  ----------------------------------------
<  Hi,
<  
<  On Mon, Jul 14, 2008 at 02:01:44PM +0200, Pavel Pokorný wrote:
<  > Hi,
<  > 
<  >    does anybody have experience with DECnet on Linux and malformed packet in
<  communication? I have CentOS 5 with DECnet
<  (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and I have problem with dnping
<  utility. When I sniffered the DECnet ping communication and opened the sniff
<  file in Ethereal, Ethereal displays that packet are malformed. Could anybody
<  help me with this issue?
<  > 
<  > Thank you.
<  > 
<  > Pavel
<  >
<  What does ethereal use to parse the packet? If its using libpcap like
<  tcpdump, then its largely broken for DECnet. Otherwise please post a
<  dump of the packet which you think is malformed,
<  
<  Steve.
<   
<  > -------------------------------------------------------------------------
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<  > _______________________________________________
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<  > 
<  > Linux-decnet-user mailing list
<  > Lin...@li...
<  > https://lists.sourceforge.net/lists/listinfo/linux-decnet-user
<  > 
<  
<  -------------------------------------------------------------------------
<  Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW!
<  Studies have shown that voting for your favorite open source project,
<  along with a healthy diet, reduces your potential for chronic lameness
<  and boredom. Vote Now at http://www.sourceforge.net/community/cca08
<  _______________________________________________
<  Project Home Page: http://linux-decnet.wiki.sourceforge.net/
<  
<  Linux-decnet-user mailing list
<  Lin...@li...
<  https://lists.sourceforge.net/lists/listinfo/linux-decnet-user
<  
<  
<  
<

I use WinPcap 4.0.2 with Ethereal for parsing the packets. I have attached example of communication (my node is 30.459).

The issue appears suddenly. The dnping was working but now finish with timeout. I don't know what the reason is  - if there is an issue in network or on my DECnet server with CentOS. When I send dnping from CentOS to the VAX server I don't receive response. When the VAX server ping my CentOS server, I receive  "Connect initiate packet" on CentOS and send "acknowledge" and "Connect confirm" back to the VAX. But the VAX server send "Retransmitted connect initiate packet" back to CentOS and CentOS send "Connect confirm again". I think that either packets are really malformed or they are filtered in network and they don't reach the VAX server.

Thanks for help.

Pavel

Pavel

Re: [Linux-decnet-user] DECnet - Malformed Packet: DEC_DNA

[Christine C. <chr...@go...>]

Pavel Pokorný wrote:
> Hi,
> 
>    does anybody have experience with DECnet on Linux and malformed packet in communication? I have CentOS 5 with DECnet (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and I have problem with dnping utility. When I sniffered the DECnet ping communication and opened the sniff file in Ethereal, Ethereal displays that packet are malformed. Could anybody help me with this issue?
> 

Without wanting to be judgemental on the issue I would first suspect 
ethereal/wireshark. If the packets are returned correctly from a remote 
(DEC) host then they are likely to be OK. If you're getting actually 
malformed packets then a VMS system won't touch them.

If they are malformed then I would suspect your ethernet card, driver or 
other things that are in the way of the traffic.


Is this symptomatic of another problem you are having ?
-- 

Chrissie

Re: [Linux-decnet-user] DECnet - Malformed Packet: DEC_DNA

[Steven W. <st...@ch...>]

Hi,

On Mon, Jul 14, 2008 at 02:01:44PM +0200, Pavel Pokorný wrote:
> Hi,
> 
>    does anybody have experience with DECnet on Linux and malformed packet in communication? I have CentOS 5 with DECnet (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and I have problem with dnping utility. When I sniffered the DECnet ping communication and opened the sniff file in Ethereal, Ethereal displays that packet are malformed. Could anybody help me with this issue?
> 
> Thank you.
> 
> Pavel
>
What does ethereal use to parse the packet? If its using libpcap like
tcpdump, then its largely broken for DECnet. Otherwise please post a
dump of the packet which you think is malformed,

Steve.
 
> -------------------------------------------------------------------------
> Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW!
> Studies have shown that voting for your favorite open source project,
> along with a healthy diet, reduces your potential for chronic lameness
> and boredom. Vote Now at http://www.sourceforge.net/community/cca08
> _______________________________________________
> Project Home Page: http://linux-decnet.wiki.sourceforge.net/
> 
> Linux-decnet-user mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linux-decnet-user
> 

[Linux-decnet-user] DECnet - Malformed Packet: DEC_DNA

[Pavel P. <Pa...@se...>]

Hi,

   does anybody have experience with DECnet on Linux and malformed packet in communication? I have CentOS 5 with DECnet (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and I have problem with dnping utility. When I sniffered the DECnet ping communication and opened the sniff file in Ethereal, Ethereal displays that packet are malformed. Could anybody help me with this issue?

Thank you.

Pavel

Re: [Linux-decnet-user] dnping, socket: Connection refused

[Christine C. <chr...@go...>]

Pavel Pokorný wrote:
> 
> <  ------------ Původní zpráva ------------
> <  Od: Christine Caulfield <chr...@go...>
> <  Předmět: Re: [Linux-decnet-user] dnping, socket: Connection refused
> <  Datum: 11.7.2008 15:15:44
> <  ----------------------------------------
> <  Pavel Pokorný wrote:
> <  > <  ------------ Původní zpráva ------------
> <  > <  Od: Christine Caulfield <chr...@go...>
> <  > <  Předmět: Re: [Linux-decnet-user] dnping, socket: Connection refused
> <  > <  Datum: 11.7.2008 14:18:36
> <  > <  ----------------------------------------
> <  > <  Pavel Pokorný wrote:
> <  > <  > Hi all,
> <  > <  > <  >    could anybody help me with following issue? We have 
> CentOS <  > 5.0 server with
> <  > <  DECnet support (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and 
> dnprogs
> <  > <  (dnprogs-2.38-1.i386.rpm) installed. On the network is Cisco 
> router <  > that works
> <  > <  like DECnet router. When I try to ping this router via dnping I 
> receive
> <  > <  following response "socket: Connection refused". I sniffered 
> network
> <  > <  communication and investigated that the CentOS server sent "connect
> <  > <  confirm/initiate message" to the router but the router responded 
> with
> <  > <  "disconnect initiate/confirm message" with reason: "The 
> destination <  > end user
> <  > <  does not exist". Does anybody know what is wrong? This 
> communication <  > was working
> <  > <  but unreasonably stopped.
> <  > <  > <  <  <  That message means that the remote end  isn't running 
> a <  > MIRROR object. <  dnping isn't a ping in the same low-level sense 
> that <  > an IP ping is. It <  needs a listening process at the other 
> end to <  > respond to it.
> <  > <  <  -- <  <  Chrissie
> <  > <  <  < <  > Chrissie, thank you for quick answer.
> <  > But interresting for me is following. When I pinged my CentOS from 
> <  > router and sniffered the communication the communication was 
> different. <  > There was not "connect confirm/initiate message" but 
> just "Link service <  > message". In this case there is not 
> authorization, isn't it?
> <  > <  <  Probably yes. Without seeing the trace and/or the error 
> message that <  sounds likely. A proper installation of DECnet on Linux 
> DOES install a <  mirror object (as part of dnetd).
> <  <  <  -- <  <  Chrissie
> <  <  < 
> 
> And do you know if is it possible to turn off this authentication part 
> of DECnet communication (dnping) on CentOS? I mean that CentOS send only 
> "Link service message" without "connect confirm/initiate message". So 
> the CentOS ping will be like router ping.
> 

it will never be the same as a router ping. (see the FAQ for more info) 
but you can disable the authentication, yes.

edit /etc/dnetd.conf so that the mirror line looks like this:

MIRROR         25         N         nobody     internal

--
Chrissie

Re: [Linux-decnet-user] dnping, socket: Connection refused

[Pavel P. <Pa...@se...>]

<  ------------ Původní zpráva ------------
<  Od: Christine Caulfield <chr...@go...>
<  Předmět: Re: [Linux-decnet-user] dnping, socket: Connection refused
<  Datum: 11.7.2008 15:15:44
<  ----------------------------------------
<  Pavel Pokorný wrote:
<  > <  ------------ Původní zpráva ------------
<  > <  Od: Christine Caulfield <chr...@go...>
<  > <  Předmět: Re: [Linux-decnet-user] dnping, socket: Connection refused
<  > <  Datum: 11.7.2008 14:18:36
<  > <  ----------------------------------------
<  > <  Pavel Pokorný wrote:
<  > <  > Hi all,
<  > <  > <  >    could anybody help me with following issue? We have CentOS 
<  > 5.0 server with
<  > <  DECnet support (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and dnprogs
<  > <  (dnprogs-2.38-1.i386.rpm) installed. On the network is Cisco router 
<  > that works
<  > <  like DECnet router. When I try to ping this router via dnping I receive
<  > <  following response "socket: Connection refused". I sniffered network
<  > <  communication and investigated that the CentOS server sent "connect
<  > <  confirm/initiate message" to the router but the router responded with
<  > <  "disconnect initiate/confirm message" with reason: "The destination 
<  > end user
<  > <  does not exist". Does anybody know what is wrong? This communication 
<  > was working
<  > <  but unreasonably stopped.
<  > <  > <  <  <  That message means that the remote end  isn't running a 
<  > MIRROR object. <  dnping isn't a ping in the same low-level sense that 
<  > an IP ping is. It <  needs a listening process at the other end to 
<  > respond to it.
<  > <  <  -- <  <  Chrissie
<  > <  <  < 
<  > Chrissie, thank you for quick answer.
<  > But interresting for me is following. When I pinged my CentOS from 
<  > router and sniffered the communication the communication was different. 
<  > There was not "connect confirm/initiate message" but just "Link service 
<  > message". In this case there is not authorization, isn't it?
<  > 
<  
<  Probably yes. Without seeing the trace and/or the error message that 
<  sounds likely. A proper installation of DECnet on Linux DOES install a 
<  mirror object (as part of dnetd).
<  
<  
<  -- 
<  
<  Chrissie
<  
<  
<  


And do you know if is it possible to turn off this authentication part of DECnet communication (dnping) on CentOS? I mean that CentOS send only "Link service message" without "connect confirm/initiate message". So the CentOS ping will be like router ping.

Thanks.

Pavel

Re: [Linux-decnet-user] dnping, socket: Connection refused

[Pavel P. <Pa...@se...>]

<  ------------ Původní zpráva ------------
<  Od: Christine Caulfield <chr...@go...>
<  Předmět: Re: [Linux-decnet-user] dnping, socket: Connection refused
<  Datum: 11.7.2008 14:18:36
<  ----------------------------------------
<  Pavel Pokorný wrote:
<  > Hi all,
<  > 
<  >    could anybody help me with following issue? We have CentOS 5.0 server with
<  DECnet support (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and dnprogs
<  (dnprogs-2.38-1.i386.rpm) installed. On the network is Cisco router that works
<  like DECnet router. When I try to ping this router via dnping I receive
<  following response "socket: Connection refused". I sniffered network
<  communication and investigated that the CentOS server sent "connect
<  confirm/initiate message" to the router but the router responded with
<  "disconnect initiate/confirm message" with reason: "The destination end user
<  does not exist". Does anybody know what is wrong? This communication was working
<  but unreasonably stopped.
<  > 
<  
<  
<  That message means that the remote end  isn't running a MIRROR object. 
<  dnping isn't a ping in the same low-level sense that an IP ping is. It 
<  needs a listening process at the other end to respond to it.
<  
<  -- 
<  
<  Chrissie
<  
<  
<  

Chrissie, thank you for quick answer.
But interesting for me is following. When I pinged my CentOS from router and sniffered the communication the communication was different. There was not "connect confirm/initiate message" but just "Link service message". In this case there is not authorization, isn't it?

Thank you.

Pavel

Re: [Linux-decnet-user] dnping, socket: Connection refused

[Christine C. <chr...@go...>]

Pavel Pokorný wrote:
> Hi all,
> 
>    could anybody help me with following issue? We have CentOS 5.0 server with DECnet support (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and dnprogs (dnprogs-2.38-1.i386.rpm) installed. On the network is Cisco router that works like DECnet router. When I try to ping this router via dnping I receive following response "socket: Connection refused". I sniffered network communication and investigated that the CentOS server sent "connect confirm/initiate message" to the router but the router responded with "disconnect initiate/confirm message" with reason: "The destination end user does not exist". Does anybody know what is wrong? This communication was working but unreasonably stopped.
> 
> Thank for help.
> 

I've added a note about this to the FAQ as it seems to come up quite 
frequently.

http://linux-decnet.wiki.sourceforge.net/FAQ5#ping

-- 

Chrissie

Re: [Linux-decnet-user] dnping, socket: Connection refused

[Christine C. <chr...@go...>]

Pavel Pokorný wrote:
> Hi all,
> 
>    could anybody help me with following issue? We have CentOS 5.0 server with DECnet support (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and dnprogs (dnprogs-2.38-1.i386.rpm) installed. On the network is Cisco router that works like DECnet router. When I try to ping this router via dnping I receive following response "socket: Connection refused". I sniffered network communication and investigated that the CentOS server sent "connect confirm/initiate message" to the router but the router responded with "disconnect initiate/confirm message" with reason: "The destination end user does not exist". Does anybody know what is wrong? This communication was working but unreasonably stopped.
> 


That message means that the remote end  isn't running a MIRROR object. 
dnping isn't a ping in the same low-level sense that an IP ping is. It 
needs a listening process at the other end to respond to it.

-- 

Chrissie

[Linux-decnet-user] dnping, socket: Connection refused

[Pavel P. <Pa...@se...>]

Hi all,

   could anybody help me with following issue? We have CentOS 5.0 server with DECnet support (kernel-2.6.18-53.1.14.el5.decnet.i686.rpm) and dnprogs (dnprogs-2.38-1.i386.rpm) installed. On the network is Cisco router that works like DECnet router. When I try to ping this router via dnping I receive following response "socket: Connection refused". I sniffered network communication and investigated that the CentOS server sent "connect confirm/initiate message" to the router but the router responded with "disconnect initiate/confirm message" with reason: "The destination end user does not exist". Does anybody know what is wrong? This communication was working but unreasonably stopped.

Thank for help.

Pava