• How to reboot
• Getting DECnet Node Numbers
• Updating node name tables
• Current Configuration for CERN DECnet Routers
• Table of DDCMP circuits
• DECnet circuits down

How to reboot The DECnet routers reboot automatically in case of problems so it is extremely rare that they need to be rebooted by hand. The only condition under which this has proved useful so far is when the NML (Network Management Language) object crahes. This results in the ALARM system displaying the message "CERNxx is down". In fact the traffic is being routed correctly; only the monitoring capability is lost. The most effective way to reboot is to physically power off and on the router concerned. However first make sure that know how to restart the CAMTEC X.25 line (see the section 'DECnet Circuits Down'). @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Getting DECnet Node Numbers The Operations Group (in collaboration with CS Group) is responsible for allocating DECnet node numbers at CERN. Requests for node numbers should be sent to: decnet-support&commat.vxgift.cern.ch or vxgift::decnet-support If a request is urgent then the Network Operator can be contacted directly by telephone (4927). This phone number will always be answered and in the worst case the requestor is referred to a backup person for node number allocation. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Invoking NCP (Network Control Program) NCP (Network Control Program) is the utility for accessing the DECnet Data Base. You should define the NCP command in VMS by typing (or adding to your login.com file) the command: ncp :== $ncp Now from VMS or ULTRIX (running DECnet) you can invoke NCP by simply typing the command, ncp . @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Updating node name tables The CERN master copy of DECnet node names is VXCERN. CERN nodes are added to the NCP data base on VXCRNA automatically by the Oracle data base software which allocates the node numbers. VXCRNB is updated soon afterwards and the Interlink gateways (CERNVM and CRNVMB) are updated manually on roughly a weekly basis or on request.

To check if a node is defined on VXCERN:

To check if a node is defined locally:

To define a new node name: NCP> define node x.y name <name> NCP> set node x.y all where x.y refers to node number y in area x. The above commands must be issued from a privileged account. The define command updates the permanent data base. The set command updates the volatile data base from the permanent.

To update node names from the master copy on VXCRNB:

DECnet Circuits down If the ALARM system indicates that a DECnet circuit is down then normally the traffic will flow over a backup route. There is usually a degradation in performance but DECnet connections will continue to work. The only circuit without a backup route is x25-spain. (The backup route to Desy, via INFN, can be unstable). You can check the status of DECnet circuits on a router, e.g. cernr1, using the following NCP command from any DECnet node: NCP> tell cernr1 show know circuits The normal status of a DECnet circuit is 'on' followed by the DECnet node number of the adjacent router. A DECnet circuit is considered down when its status is 'on -synchronizing'. This means that the circuit is continually trying to restart itself but without success. When a DECnet circuit is down, this usually indicates a problem with the leased line to the remote site. If the circuit name starts with the prefix 'X25-' then the circuit requires X.25 to be functioning correctly. If an individual DECnet circuit is down, the problem is generally resolved after intervention of the PTT, although you should first try to contact the remote DECnet manager (see section 'HEP DECnet Contacts') to ensure that the problem is not due to changes at the remote site. If several DECnet circuits with the prefix 'X25-' are down simultaneously, this tends to indicate an X.25 problem at CERN. If several X25-xxx circuits are down on the same router, it may be necessary to restart CAMTEC line 1 on the appropriate CAMTEC switch. CERNR1 is connected to CAMTEC switch 0 and CERNR2 is connected to CAMTEC switch 1. There is a known problem with the line between the CAMTEC switch and the DECnet routers. When a router reboots (for whatever reason) the CAMTEC line generally needs to be restarted. To check for this situation on cernr1, invoke NCP on any DECnet node and type: NCP>tell cernr1 sho know dte If the dte is in state 'unsynchronized' then the X.25 line must be reset from the CAMTEC side. Resetting the line from the DECnet router has no effect. See also the normal statusof circuits on cernr1 and cernr2. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

How to restart a DECnet circuit Restarting a DECnet circuit rarely helps to resolve a problem, however telling somebody that you have tried restarting it often makes them happy, so all DECnet managers should know how to do it. Below is an example of restarting the circuit x25-spain on cernr1. Invoke NCP on any DECnet node and type: NCP> set exec node cernr1 user xxx pass yyy NCP> set circ x25-spain state off NCP> set circ x25-spain state on NCP> exit @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Changing a DECnet circuit cost Circuit costs are the mechanism DECnet uses for routing. An incorrect setting for a circuit cost can have a drastic affect on worldwide DECnet traffic. Changes to circuit costs require the agreement of the CERN DECnet coordinator (CS Group). If an urgent request is received in her absence, then the cost can be changed using the commands below. However, the request must come from or be agreed to by the relevant European HEP DECnet Manager. A list of the managers and their contact details is given in a later section. The example below changes the cost of the circuit x25-spain on cernr1 to the value 23. Invoke NCP on any DECnet node and type: NCP> set exec node cernr1 user xxx pass yyy NCP> set circ x25-spain state off NCP> set circ x25-spain cost 23 NCP> set circ x25-spain state on .br NCP> exit </HP2> The above commands only change the circuit cost in the volatile data base of the router itself so the changes will be lost next time the router reboots. Normally it will be sufficient to inform the DECnet coordinator so that she can update the permanent data base on her return. If you need the permanent data base updated before her return then follow the instructions in the section below. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ <H1>Updating the Permanent Data Base The master copies of the permanent data bases for the DECnet routers is on UXCSB1. Backup copies are stored on UXDDB1. Updating the permanent data base requires privileged access to these nodes and should be normally be performed by the DECnet Coordinator. The information given here is only expected to be used in case of urgent changes requiring a router to reboot. First update the permanent data base on UXCSB1: <XMP> $ run sys$system:x25rouperm it asks you for the name of the router you want to modify ... X25ROUPERM> enter here your NCP commands e.g. set circ x25-spain cost 23 X25ROUPERM> exit Now copy the files to UXDDB1: copy sys$common:[decserver]x25cernr*.sys uxddb1::sys$common:[decserver] You may need help from the UXDDB1 system manager for the copy. You must notify any changes of the permanent data base to the DECnet Coordinator since she does not configure the routers using the above mechanism. In order to have a documented record and to ease the configuration of future routers, the DECnet Coordinator has chosen to enter NCP commands in command files stored on UXCSB1 in the directory tree sys$common:[sysmgr.decnet]. These command files are invoked from within the X25ROUPERM program rather than entering the individual commands by hand. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Examining the log files The DECnet routers are configured to log a useful subset of DECnet events to the file uxcsb1::decnet$log:netevents.log Other useful files in the directory uxcsb1::decnet$log are: circ_counters.log Circuit counters for CERNR1 & CERNR2 line_counters.log Line counters for CERNR1 & CERNR2 cernit.log Circuit & Line counters for CERNIT All files in this directory have world read access from any DECnet node. All *.log files are renamed every morning at 08:00 to *.old with versions kept for the previous 10 days. @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Where to find more information Digital provide some excellent documentation for DECnet. My copy of the X25Router 2000 manual is on the shelf behind my terminal (office 31-2-016). Copies of the VMS manuals are on the shelfs on the floor beside the filing cabinets. The most useful manuals are listed below:

• X25Router 2000 V1.1 (Management Guide and Problem Solving Guide)
• VMS System Management Vol 5A, Networking, Networking Manual
• VMS System Management Vol 5B, Networking, Network Control Program (NCP)

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Security Incidents and Information channels In case of security incidents or informational messages of interest to all CERN DECnet connections (e.g. planned downtime), you can send mail to the following distribution list: cern-decnet-info&commat.vxgift.cern.ch or vxgift::cern-decnet-info

HEP DECnet Contacts Below is a list of contacts for the key DECnet circuits. The first name listed is the official DECnet contact for the circuit. Other names for each circuit are alternative people you can try to contact when the offical person is absent. X25-IN2P3 (area 32 on CERNR2) Noel Giraud IN2P3, Lyon tel. +33 78930880 E-mail: ccpnvx::giraud Daniel Charnay IN2P3, Lyon E-mail: ccpnvx::system Rene' Bilhaut Laboratoire de l'Accelerateur Lineaire (IN2P3) Bat. 200 91405 Orsay France tel. +33 1 64468338 E-mail: lalvax::bilhaut, or EARN, bilhaut&commat.frlal51 X25-DESY (area 13 on CERNR2) Matthias Clausen KRYK, Deutches Elektronen-Synchrotron DESY Notkestrasse 85 2000 Hamburg 52 Germany tel. +40 89 98 32 56 E-mail: claus&commat.heracc.vms.desy.dbp.de, or, heracc::claus Michael Ernst (X.25) DESY X25-NORDUNET (area 21 on CERNR1) Ingrid Dahl-Jensen UNI-C, Danish Computing Centre for Research and Education DTH, bygning 305 DK-2800 Lyngby tel. +45 45 93 83 55 E-mail: unic&commat.nbivax.dk, or, nbivax::unic G|ran Bengtson E-mail: goeran@ae.chalmers.se Peter Villemoes UNI-C tel. +45 45 93 83 55 E-mail: rkupv&commat.vm.uni-c.dk UK (area 19 on CERNR1) David Kelsey Particle Physics Department, Rutherford Appleton Laboratory Chilton, DIDCOT Oxon OX11 0QX United Kingdom tel. +44 235 44 5746 E-mail: Kelsey&commat.v2.rl.ac.uk, or, rlv2::kelsey Jason Leake RAL E-mail: leake&commat.v2.rl.ac.uk or rlv2::leake X25-CH (area 20 on CERNR2) Roland Kessi Computing Division, Paul Scherrer Institute CH-5232 Villigen tel. +41 56 993602 telefax: 993294 PSI CH E-mail: kessi&commat.rzsin.sin.ch, or, psiclu::kessi Herman Kneis PSI tel. +41 56 993610 E-mail: kneis&commat.rzsin.sin.ch INFN (areas 37-39 on CERNIT) Antonia Ghiselli Istituto Nazionale Fisica Nucleare, INFN-CNAF Vl. Ercolani 8 40138 - Bologna Italy Tel. +39 51 498267 telefax: 498135 E-mail: ghiselli&commat.cnaf.infn.it, or, infngw::ghiselli Umberto Zanotti (Multiplexor) INFN-CNAF Tel. +39 51 498284 CNAF Operations tel. +39 51 489327 E-mail: infngw::cnaf X25-SPAIN (area 16 on CERNR1) Angel Camacho Grupo de Altas Energias Universidad de Cantabria Avda. de los Castros s/n 39005 - Santander (Spain) Tel. +34 42 201464 (458) telefax: 201402 E-mail: esanmx::camacho, or camacho&commat.esanvx.unican.es Antonio Mollinedo CIEMAT Madrid Tel. +34 1 3466176 (direct) +34 1 3466000 (exchange) E-mail: ciemat::molli or psi%2145212025022::molli USA (areas 41-46 on CERNR2) Phil DeMar Fermilab P.O. Box 500; Ms 234 Batavia, Ill. 60510, U.S.A. Tel. 312 840 3678 Telefax. (312) 840 4343 E-mail: fnal::demar or demar&commat.fnal.bitnet or demar&commat.fnnet.fnal.gov Vyto Grigaliunas Fermilab Tel. (312) 840-2539 E-mail: fnal::vyto or vyto&commat.fnal.bitnet or vyto&commat.fnnet.fnal.gov