Cisco IOS Scripting with TCL Configuration Guide, Cisco IOS XE Amsterdam 17.x

Caution

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The use of Tcl server sockets to listen to telnet and FTP ports (23 and 21 respectively) will preempt the normal handling of these ports in Cisco IOS XE software.

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Table 1. Tcl Command Options That Behave Differently in Cisco IOS XE Software

Command

Keyword

Argument

Supported

Comments

after

script

Partially

When the CLI tclsh command is used, there is no event loop implemented unless Embedded Syslog Manager (ESM) is active on the same router. Commands entered using the after Tcl command will not run unless forced using the update command. Sleep mode (the after command) works only with the ms keyword.

-time

atime

The optional -time keyword to set the file access time is not supported in Cisco IOS XE software.

-time

mtime

The optional -time keyword to set the file modification time is not supported in Cisco IOS XE software.

fileevent

Partially

When the CLI tclsh command is used, there is no event loop implemented unless Embedded Syslog Manager (ESM) is active on the same router. Commands entered using the fileevent Tcl command will not run unless forced using the update command.

history

! n

Partially

The ! n shortcut does not work in Cisco IOS XE software. Use the history Tcl command with the redo n keyword.

When the CLI load command is used, an error message stating “dynamic loading not available on this system” is displayed.

Table 2. Cisco IOS XE Custom Tcl Command Extensions

Command

Description

ios_config

Runs a Cisco IOS XE CLI configuration command.

log_user

Toggles Tcl command output under Tcl configuration mode.

typeahead

Writes text to the router standard input (stdin) buffer file.

tclquit

Leave Tcl shell--synonym for exit .

Table 3. Cisco IOS XE Custom Tcl Command Extensions for SNMP MIB Access

Command

Description

snmp_getbulk

Retrieves a large section of a MIB table. This command is similar to the SNMP getbulk command. The syntax is in the following format:

snmp_getbulk community-string non-repeaters max-repetitions oid [oid2 oid3 ...]

• Use the community-string argument to specify the SNMP community from which the objects will be retrieved.

• Use the non-repeaters argument to specify the number of objects that can be retrieved with a get-next operation.

• Use the max-repetitions argument to specify the maximum number of get-next operations to attempt while trying to retrieve the remaining objects.

• Use the oid argument to specify the object ID(s) to retrieve.

snmp_getid

Retrieves the following variables from the SNMP entity on the router:

• sysDescr.0

• sysObjectID.0

• sysUpTime.0

• sysContact.0

• sysName.0

• sysLocation.0

This command is similar to the SNMP getid command. The syntax is in the following format:

snmp_getid community-string

snmp_getnext

Retrieves a set of individual variables from the SNMP entity on the router. This command is similar to the SNMP getnext command. The syntax is in the following format:

snmp_getnext community-string oid [oid2 oid3 ...]

snmp_getone

Retrieves a set of individual variables from the SNMP entity on the router. This command is similar to the SNMP getone command. The syntax is in the following format:

snmp_getone community-string oid [oid2 oid3 ...]

snmp_setany

Retrieves the current values of the specified variables and then performs a set request on the variables. This command is similar to the SNMP setany command. The syntax is in the following format:

snmp_setany community-string oid type val [oid2 type2 val2 ...]

• Use the type argument to specify the type of object to retrieve. The type can be one of the following:
  • -i --Integer. A 32-bit number used to specify a numbered type within the context of a managed object. For example, to set the operational status of a router interface, 1 represents up and 2 represents down.
  • -u --Unsigned32. A 32-bit number used to represent decimal values in the range from 0 to 2 32 - 1 inclusive.
  • -c --Counter32. A 32-bit number with a minimum value of 0 and a maximum value of 2 32 - 1. When the maximum value is reached, the counter resets to 0 and starts again.
  • -g --Gauge. A 32-bit number with a minimum value of 0 and a maximum value of 2 32 - 1. The number can increase or decrease at will. For example, the interface speed on a router is measured using a gauge object type.
  • -o --Octet string. An octet string--in hex notation--used to represent physical addresses.
  • -d --Display string. An octet string--in text notation--used to represent text strings.
  • -ipv4 --IP version 4 address.
  • -oid --Object ID.

• Use the val argument to specify the value of object ID(s) to retrieve.

Step 1

enable

Example:

Router> enable

Enables the privileged EXEC mode. Enter your password, if prompted.

If you're encoding your files, or if you're using an initialization script, or both, perform steps 2 through 6 in this procedure. Else, go to step 7.

Step 2

configure terminal

Example:

Router# configure terminal

Enters the global configuration mode.

Step 3

scripting tcl encdir location-url

Example:

Router(config)# scripting tcl encdir tftp://10.18.117.23/enctcl/

Specifies the default location of external encoding files used by the Tcl encoding command.

Step 4

scripting tcl init init-url

Example:

Router(config)# scripting tcl init ftp://user:[email protected]/tclscript/initfiles3.tcl

Specifies an initialization script to run when you enable the Tcl shell.

Step 5

scripting tcl low-memory bytes

Example:

Router(config)# scripting tcl low-memory 33117513

Specifies a low memory mark for free memory for the Tcl-based applications. You can set the memory threshold anywhere 0–4294967295 bytes.

Step 6

Example:

Router(config)# exit

Exits the global configuration mode and returns to the privileged EXEC mode.

Step 7

tclsh

Example:

Router# tclsh

Enables the interactive Tcl shell and enters the Tcl configuration mode.

Step 8

Enter the required Tcl command language syntax.

Example:

Router(tcl)# proc get_bri {}

The commands you enter in the Tcl configuration mode are sent first to the interactive Tcl interpreter. If the command isn't a valid Tcl command, it's then sent to the CLI parser.

Step 9

ios_config “ cmd ” “ cmd-option ”

Example:

Router(tcl)# ios_config “interface Ethernet 2/0” “no keepalive”

Modifies the router configuration using a Tcl script by specifying the Tcl command ios_config with CLI commands and options.

In this example, the first argument in quotes configures an Ethernet interface and enters the interface configuration mode. The second argument in quotes sets the keepalive option, which keeps the connection open for multiple servicing requests. If you entered these two CLI statements on separate Tcl command lines, the configuration does not work.

Step 10

socket -myaddr addr -myport port -myvrf vrf-table-name host port

Example:

Router(tcl)# socket -myaddr 10.4.9.34 -myport 12345 -myvrf testvrf 12346

Specifies the client socket and allows a TCL interpreter to connect via TCP over IPv4/IPv6 and opens a TCP network connection. You can specify a port and host to connect to; there must be a server to accept connections on this port.

• -myaddr addr – the domain name or the IP address of the client-side network interface. Use this option if the client machine has multiple network interfaces.

• -myport port -- the port number required for the client connection.

• -myvrf [vrf_table_name ]-- the vrf table name. This option returns the local VRF table name for the specified socket. If you have not configured a VRF table for the given socket the system displays a TCL_ERROR. A “No VRF table configured” message is appended to the interpreter result.

Step 11

socket - server -myaddr addr -myvrf vrf-table-name port

Example:

Router(tcl)# socket -server test -myvrf testvrf 12348

Specifies the server socket and allows a TCL interpreter to connect via TCP over IPv4/IPv6 and opens a TCP network connection. If the port is zero, Cisco IOS allocates a free port to the server socket by using the fconfigure command to read the -sock0 argument.

• -myaddr addr – the domain name or the IP address of the server-side network interface. Use this option if the client machine has multiple network interfaces.

• -myvrf vrf -- the vrf table name. This option returns the local VRF table name for the specified socket. If you do not configure the vrf table the command returns a TCL_ERROR. The system displays the “Cannot obtain VRF Table ID for VRF_table_name” message.

Step 12

fconfigure channelname - remote [host port ] - broadcast boolean - vrf [vrf_table_name ]

Example:

Router(tcl)# fconfigure sock1 -vrf vrf1 -remote [list 10.4.9.37 56009] -broadcast 1

Specifies the options in a channel.

• In case of UDP sockets that are created using the udp_open command, you can map the UDP socket to a VRF using the fconfigure command.

• This command also enables you to display the properties of the channel.

• -broadcast -- enables or disables broadcasting.

Step 13

udp_open -ipv6 port

Example:

Router(tcl)# udp_open -ipv6 56005

Opens a UDP socket.

If you specify a port, the UDP socket is opened on that port. Optionally, the system chooses a port and you can use the fconfigure command to obtain the port number. If you specify the -ipv6 argument, the socket is opened specifying the AF_INET6 protocol family.

Step 14

udp_peek sock -buffersize buffer-size

Example:

Router(tcl)# udp_peek sock0 -buffersize 100

Enables peeking into a UDP socket.

• -buffersize buffer-size --specifies the buffersize.

Step 15

exec “ exec-cmd ”

Example:

Router(tcl)# exec “show interfaces”

(Optional) Executes the Cisco IOS CLI EXEC mode commands from a Tcl script by specifying the Tcl command exec with the CLI commands.

• In this example, the system displays the interface information for the router.

Step 16

Example:

Router(tcl)# exit

Exits Tcl configuration mode and returns to privileged EXEC mode.

Router# tclsh
Router(tcl)# exec “show interfaces”
Ethernet 0 is up, line protocol is up
  Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c)
  Internet address is 10.108.28.8, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set, keepalive set (10 sec)
  ARP type: ARPA, ARP Timeout 4:00:00
  Last input 0:00:00, output 0:00:00, output hang never
  Last clearing of "show interface" counters 0:00:00
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 2000 bits/sec, 4 packets/sec
     1127576 packets input, 447251251 bytes, 0 no buffer
     Received 354125 broadcasts, 0 runts, 0 giants, 57186* throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     5332142 packets output, 496316039 bytes, 0 underruns
     0 output errors, 432 collisions, 0 interface resets, 0 restarts
.
.
.

Command or Action Purpose Step 1

enable

Example:

Router> enable

Enables privileged EXEC mode.

• Enter your password if prompted.

Step 2

tclsh

Example:

Router# tclsh

Enables the interactive Tcl shell and enters Tcl configuration mode.

Step 3

Enter the Tcl source command with the filename and path.

Example:

Router(tcl)# source slot0:test.tcl

Commands entered in Tcl configuration mode are sent first to the interactive Tcl interpreter. If the command is not a valid Tcl command, it is then sent to the CLI parser.

Step 4

Example:

Router(tcl)# exit

Exits Tcl configuration mode and returns to privileged EXEC mode.

tclsh
proc get_bri {} {
    set check ""
    set int_out [exec "show interfaces"]
    foreach int [regexp -all -line -inline "(^BRI\[0-9]/\[0-9])" $int_out] {
        if {![string equal $check $int]} {
            if {[info exists bri_out]} {
                append bri_out "," $int
             } else {
                 set bri_out $int
             }
             set check $int
        }
    }
    return $bri_out
}

##
## Place required comments here!!!
##
package provide sendmail 2.0
# Sendmail procedure for Support
namespace eval ::sendmail {
    namespace export initialize configure sendmessage sendfile
    array set ::sendmail::sendmail {
        smtphost    mailhub
        from        ""
        friendly    ""
    }
    proc configure {} {}
    proc initialize {smtphost from friendly} {
        variable sendmail
        if {[string length $smtphost]} then {
            set sendmail(smtphost) $smtphost 
        }
        if {[string length $from]} then {
            set sendmail(from) $from
        }
        if {[string length $friendly]} then {
            set sendmail(friendly) $friendly
        }
    }
    proc sendmessage {toList subject body {tcl_trace 0}} {
        variable sendmail
        set smtphost $sendmail(smtphost)
        set from $sendmail(from)
        set friendly $sendmail(friendly)
        if {$trace} then {
            puts stdout "Connecting to $smtphost:25"
        }
        set sockid [socket $smtphost 25]
## DEBUG
set status [catch {
        puts $sockid "HELO $smtphost"
        flush $sockid
        set result [gets $sockid]
        if {$trace} then {
            puts stdout "HELO $smtphost\n\t$result"
        }
        puts $sockid "MAIL From:<$from>"
        flush $sockid
        set result [gets $sockid]
        if {$trace} then {
            puts stdout "MAIL From:<$from>\n\t$result"
        }
        foreach to $toList {
            puts $sockid "RCPT To:<$to>"
            flush $sockid
        }
        set result [gets $sockid]
        if {$trace} then {
            puts stdout "RCPT To:<$to>\n\t$result"
        }
        puts  $sockid "DATA "
        flush $sockid
        set result [gets  $sockid]
        if {$trace} then {
            puts stdout "DATA \n\t$result"
        }
        puts  $sockid "From: $friendly <$from>"
        foreach to $toList {
            puts $sockid "To:<$to>"
        }
        puts  $sockid "Subject: $subject"
        puts  $sockid "\n"
        foreach line [split $body "\n"] {
            puts  $sockid " $line"
        }
        puts  $sockid "."
        puts  $sockid "QUIT"
        flush $sockid
        set result [gets  $sockid]
        if {$trace} then {
            puts stdout "QUIT\n\t$result"
        }
} result]
        catch {close $sockid }
        if {$status} then {
	      return -code error $result
        }
        return
    }
    proc sendfile {toList filename subject {tcl_trace 0}} {
        set fd [open $filename r]
        sendmessage $toList $subject [read $fd] $trace
        return
    }
}

snmp-server community public RO
snmp-server community private RW
tclsh
  snmp_getbulk public 1 5 1.3.6.1.2.1.1.2.0  1.3.6.1.2.1.2.2.1.2  1.3.6.1.2.1.2.2.1.3
  {<obj oid='sysUpTime.0' val='1336090'/>}
  {<obj oid='ifDescr.1' val='FastEthernet0/0'/>}
  {<obj oid='ifType.1' val='6'/>}
  {<obj oid='ifDescr.2' val='FastEthernet1/0'/>}
  {<obj oid='ifType.2' val='6'/>}
  {<obj oid='ifDescr.3' val='Ethernet2/0'/>}
  {<obj oid='ifType.3' val='6'/>}
  {<obj oid='ifDescr.4' val='Ethernet2/1'/>}
  {<obj oid='ifType.4' val='6'/>}
  {<obj oid='ifDescr.5' val='Ethernet2/2'/>}
  {<obj oid='ifType.5' val='6'/>}

tclsh
 snmp_getid public
 {<obj oid='system.1.0' val='Cisco Internetwork Operating System Software 
 Cisco IOS XE(tm) 7200 Software (C7200-IK9S-M), Experimental Version 12.3(20030507:225511)
 [geotpi2itd1 124]
 Copyright (c) 1986-2003 by Cisco Systems, Inc.
 Compiled Wed 21-May-03 16:16 by engineer'/>} 
 {<obj oid='system.2.0' val='products.223'/>}
 {<obj oid='sysUpTime.0' val='6664317'/>} 
 {<obj oid='system.4.0' val='1-800-553-2447 - phone the TAC'/>}
 {<obj oid='system.5.0' val='c7200.myCompany.com'/>}
 {<obj oid='system.6.0' val='Bldg 24, San Jose, CA'/>}

snmp_getnext public 1.3.6.1.2.1.1.1.0 1.3.6.1.2.1.1.2.0 
 {<obj oid='system.2.0' val='products.223'/>}
 {<obj oid='sysUpTime.0' val='6683320'/>}

snmp_getone public 1.3.6.1.2.1.1.1.0 1.3.6.1.2.1.1.2.0 
 {<obj oid='system.1.0' val='Cisco Internetwork Operating System Software 
 Cisco IOS XE(tm) 7200 Software (C7200-IK9S-M), Experimental Version 12.3(20030507:225511)
 [geotpi2itd1 124]
 Copyright (c) 1986-2003 by Cisco Systems, Inc.
 Compiled Wed 21-May-03 16:16 by engineer'/>} 
 {<obj oid='system.2.0' val='products.223'/>}

tclsh
 snmp_setany private 1.3.6.1.2.1.1.5.0 -d TCLSNMP-HOST
 {<obj oid='system.5.0' val='TCLSNMP-HOST'/>}

Related Topic

Document Title

Cisco PKI Overview: Understanding and Planning a PKI

Implementing and Managing a PKI

Security Configuration Guide, Release 12.4

PKI commands: complete command syntax, command mode, command history, defaults, usage guidelines, and examples.

Cisco IOS Security Command Reference, Release 12.4

Standard

Title

MIBs Link

To locate and download MIBs for selected platforms, Cisco software releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

Title

Description

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/techsupport

Table 4. Feature Information for Cisco IOS XE Scripting with Tcl

Feature Name

Releases

Feature Information

Cisco IOS XE Scripting with Tcl

Cisco IOS XE

The Cisco IOS XE Scripting with Tcl feature provides the ability to run Tool Command Language (Tcl) version 8.3.4 commands from the Cisco IOS XE command-line interface (CLI).

In Cisco IOS XE Release 2.1, this feature was introduced on Cisco ASR 1000 Series Aggregation Services Routers.

The following commands were introduced or modified: scripting tcl encdir , scripting tcl init , scripting tcl low-memory , tclquit , tclsh .

Tcl SNMP MIB Access

Cisco IOS XE

The Tcl SNMP MIB Access feature introduces a set of UNIX-like SNMP commands to make access to Simple Network Management Protocol (SNMP) MIB objects easier.