EEM script to update the description of an interface

alanssie · ‎06-12-2024

Information

This code is looking at neighbour discovery, learns remote name and remote interface and push it in the

description of the local interface

Note: the length of the remote interface name can be tuned by set len_intn [value]

code 2024-first_version

::cisco::eem::event_register_neighbor_discovery interface Gig cdp add

namespace import ::cisco::eem::*

namespace import ::cisco::lib::*

##################################################################################

#

# Redistribution and use in source and binary forms, with or without

# modification, are permitted provided that the following conditions

# are met:

# 1. Redistributions of source code must retain the above copyright

# notice, this list of conditions and the following disclaimer.

# 2. Redistributions in binary form must reproduce the above copyright

# notice, this list of conditions and the following disclaimer in the

# documentation and/or other materials provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

#Platform

#---------

# Tested on NCS (should work on any ios_xr platform)

# Purpose

# ========

# Grab CDP even and modify the description of the interface coming up

array set arr_einfo [event_reqinfo]

## Number of character of an interface needed, start counting from 0 (1 == 2 characters)

set len_intn 1

if [catch {cli_open} result] {

error $result $errorInfo

} else {

array set cli1 $result

}

if [catch {cli_exec $cli1(fd) "enable"} _cli_result] {

error $_cli_result $errorInfo

}

if [catch {cli_exec $cli1(fd) "config t"} _cli_result] {

error $_cli_result $errorInfo

}

if [catch {cli_exec $cli1(fd) "interface $arr_einfo(local_intf_name)"} _cli_result] {

error $_cli_result $errorInfo

}

if [catch {cli_exec $cli1(fd) "description *** [lindex [split $arr_einfo(cdp_entry_name) "."] 0] [string range $arr_einfo(port_id) 0 $len_intn] ***"} _cli_result] {

error $_cli_result $errorInfo

}

if [catch {cli_exec $cli1(fd) "commit"} _cli_result] {

error $_cli_result $errorInfo

}

if [catch {cli_exec $cli1(fd) "end"} _cli_result] {

error $_cli_result $errorInfo

}

action_syslog msg "EEM script updated description on $arr_einfo(local_intf_name) and commit config"

catch {cli_close $cli1(fd) $cli1(tty_id)} result

code 2024-1708 (split char. and slot...)

::cisco::eem::event_register_neighbor_discovery interface Gig cdp add
namespace import ::cisco::eem::*
namespace import ::cisco::lib::*

##################################################################################
#
# Copyright (c) 2024 Alain Lanssiers <alanssie@cisco.com>
#
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
#Platform
#---------
# Tested on NCS (should work on any ios_r, ios_xe platform)
# Purpose
# ========
# Grab CDP even and modify the description of the interface coming up
# version 2024-0718 added possibility to rstrict length of aplha character but keep the x/y/z/.. after

array set arr_einfo [event_reqinfo]

## Number of character of an interface needed, start counting from 0 (1 == 2 characters)
set len_intn 1
regsub -all {[[:alpha:]]+} $arr_einfo(port_id) {} int_num

if [catch {cli_open} result] {
error $result $errorInfo
} else {
array set cli1 $result
}

if [catch {cli_exec $cli1(fd) "enable"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "config t"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "interface $arr_einfo(local_intf_name)"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "description *** [lindex [split $arr_einfo(cdp_entry_name) "."] 0] [string range $arr_einfo(port_id) 0 $len_intn]$int_num ***"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "commit"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "end"} _cli_result] {
error $_cli_result $errorInfo
}

action_syslog msg "EEM script updated description on $arr_einfo(local_intf_name) and commit config"
catch {cli_close $cli1(fd) $cli1(tty_id)} result

code 2024-2024-1810 (adding wr for ios-xe)

::cisco::eem::event_register_neighbor_discovery interface Gig cdp add

namespace import ::cisco::eem::*
namespace import ::cisco::lib::*

##################################################################################
#
# Copyright (c) 2024 Alain Lanssiers <alanssie@cisco.com>
#
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
#Platform
#---------
# Tested on NCS (should work on any ios_r, ios_xe platform)
# Purpose
# ========
# Grab CDP even and modify the description of the interface coming up
# version 2024-0718 added possibility to rstrict length of aplha character but keep the x/y/z/.. after
# tested on ios-xr
# version 2024-1810 added wr for saving config on ios ios-xe
# tested on ios-xe

array set arr_einfo [event_reqinfo]

## Number of character of an interface needed, start counting from 0 (1 == 2 characters)
set len_intn 1
regsub -all {[[:alpha:]]+} $arr_einfo(port_id) {} int_num

if [catch {cli_open} result] {
error $result $errorInfo
} else {
array set cli1 $result
}

if [catch {cli_exec $cli1(fd) "enable"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "config t"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "interface $arr_einfo(local_intf_name)"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "description *** [lindex [split $arr_einfo(cdp_entry_name) "."] 0] [string range $arr_einfo(port_id) 0 $len_intn]$int_num ***"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "commit"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "end"} _cli_result] {
error $_cli_result $errorInfo
}
if [catch {cli_exec $cli1(fd) "wr"} _cli_result] {
error $_cli_result $errorInfo
}
action_syslog msg "EEM script updated description on $arr_einfo(local_intf_name) and commit config"
catch {cli_close $cli1(fd) $cli1(tty_id)} result

Volker Mueller · ‎10-14-2024

Hi Alan,

on NCS, a IOSXR-Box, it works.

But on a IOSXE, for Example ASR903 or Cat9300, it does not work.

I execute the script in the tclshell with:

source bootflash:EEM-Int-Desc-CDP-IOS-XR.tcl

I´m getting the following error:

invalid command name "::cisco::eem::event_register_neighbor_discovery" ^
% Invalid input detected at '^' marker.

How can I solve this?

Leo Laohoo · ‎10-14-2024

@Volker Mueller, this is what we use on our switches:

event manager applet update-port
 event neighbor-discovery interface regexp GigabitEthernet.* cdp add
 action 100 regexp "(Switch|Trans-Bridge|Router)" "$_nd_cdp_capabilities_string"
 action 110 if $_regexp_result eq "1"
 action 200  cli command "enable"
 action 210  cli command "config t"
 action 220  cli command "interface $_nd_local_intf_name"
 action 230  regexp "^([^\.]+)" "$_nd_cdp_entry_name" match host
 action 240  cli command "description $host"
 action 500 end

(This EEM was written by @Joe Clarke.)

The EEM looks at CDP neighbors and filters the "Capabilities" for "Routers", "Switches" and "Trans-Bridge" (aka wireless access points) and updates the interface names with the hostname.

alanssie · ‎10-18-2024

Hi Volker

> > invalid command name "::cisco::eem::event_register_neighbor_discovery" ^
> > % Invalid input detected at '^' marker.

> >How can I solve this?

This registry also exist in ios-xe, so I do not think the script should complain, looking at the ^ after the registration line, I think likely something introduced a hidden character and interpret this as a command.

Note the TCL was done because there is no applet in the ios-xr, I will verify this script later on ios-xe and let you know

Alain

alanssie · ‎10-18-2024

Hi Volker

I tested locally and it ran fine, I think the copy and paste into a file picked up some garbage

so what you need to do is choose your file editor

copy first :

::cisco::eem::event_register_neighbor_discovery interface Gig cdp add

namespace import ::cisco::eem::*

namespace import ::cisco::lib::*

press return after copying all the characters and only character of one line, repeat for each line above

after that copy the rest of the script in your file

save the file

Unfortunately I cannot attach the original file here but I believe the above procedure should help

BTW there will be a version 2024-1810 that will add the "wr" for ios-xe

but since it needs to be published as I did an edit on the first, it might take sometime

Alain

Volker Mueller · ‎10-20-2024

Hi Alain,

first, thank you for your time.

I´ve done as you said.

First with "my" file. Second with the version 2024-1810 on this post.

But I´m getting the same error.

After that I´ve also convert the file with dos2unix before I tranfer it to the device, but with no luck.

I´m getting always this error:

R01(tcl)#source bootflash:EEM-Int-Desc-CDP-IOS-XE.tcl
invalid command name "::cisco::eem::event_register_neighbor_discovery" ^
% Invalid input detected at '^' marker.

R01(tcl)#

So, on which platform do you tested it?

And how do you tested?

I´ve testet it on ASR903 Version 17.12.4 and on Cat9300L Version 17.3.4

Volker

alanssie · ‎10-20-2024

Hi Volker

to register the tcl script source does not really work

example

=======

net1(tcl)#source unix:description_cdp.tcl
invalid command name "::cisco::eem::event_register_neighbor_discovery"
::cisco::eem::event_register_neighbor_discovery interface Ethernet cdp add
^
% Invalid input detected at '^' marker.

But it works fine is you register via the cli

example

net1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
net1(config)#event manager policy description_cdp.tcl authorization bypass
net1(config)#^Z
net1#sh
*Oct 21 06:30:10.784: %SYS-5-CONFIG_I: Configured from console by ww on console

net1#sho event manager policy registered
No. Class Type Event Type Trap Time Registered Name
1 script user neighbor-discovery Off Mon Oct 21 00:30:08 2024 description_cdp.tcl
interface {Ethernet} cdp add
nice 0 queue-priority normal maxrun 20.000 scheduler rp_primary Secu none

Alain

Volker Mueller · ‎10-21-2024

Hi Alain,

sorry for my stupid questions, but I´m new in case of tcl and eem.

After registering the script via CLI, the script will be executed.

But the Interface description is not there.

R01#
014657: Oct 21 09:21:53.290 CEST: %HA_EM-6-LOG: EEM-Int-Desc-CDP-IOS-XE.tcl: EEM script updated description on GigabitEthernet0/4/2 and commit config

R01#sh run int GigabitEthernet0/4/2
Building configuration...

Current configuration : 578 bytes
!
interface GigabitEthernet0/4/2
dampening
bandwidth 1000000
ip address 10.x.x.x 255.255.255.252

Thats my CLI configuration:

event manager directory user policy "bootflash:/SCRIPTS"

event manager applet CDP-VIA-TCL authorization bypass
event none
action 1.0 cli command "EEM-Int-Desc-CDP-IOS-XE.tcl"
event manager policy EEM-Int-Desc-CDP-IOS-XE.tcl

Volker

Rich R · ‎10-21-2024

@Volker Mueller an EEM script needs an event configured to trigger it to run.
As you have configured it now (event none) you could run it manually from CLI but if you want it to run automatically you must configure an event.
Take a look at the example Leo provided above for EEM on IOS-XE, then you don't need to use TCL at all. As Alain says the TCL was only provided for IOS-XR because the applet capability did not exist.

Volker Mueller · ‎10-21-2024

Hi Rich,

I have a network with IOS-XE and IOS-XR devices and I want to take the same procedure to apply the interface description.

In Leos example I only get the Device without the port.

And as I said, the tcl-script from Alain on the IOS-XE box is executet, with event none or with event neighbor-discovery interface regexp .* cdp add, but without description.

Volker

alanssie · ‎10-21-2024

Hi Volker

there needs to be a cdp event in the ios-xe to configure the interface

if you have one interface with cdp neighbor, shut on the remote and wait until cdp neighbor disappear locally

then unshut on the remote

Potentially, debug event manager cli_library to see what the script is effectively writing in the config

Alain

Volker Mueller · ‎10-21-2024

Hi Alain,

the script is OK and works on IOSXE.

The problem was "Command authorization failed."

I thought, if I configure "authorization bypass", the problem was solved. But the problem still exists.

If I configure a AAA-User for EEM, the authorization failed is gone.

Do you know, why "authorization bypass" does not work in action between EEM and TCL?

Or how can I achieve, that the script will be executed without authorization, like "normal" EEM-Applets?

Volker

Rich R · ‎10-23-2024

Hi Volker
> I have a network with IOS-XE and IOS-XR devices and I want to take the same procedure
But they are different operating systems and sometimes you can't use the exact same solution on both.