This is a new article for the blog serie called "RARE Day One". Today we will explore one of freeRouter features meant to fine tune terminal user environment and behaviour in order to best match your taste/preferences.

Requirement

  • Basic Linux/Unix knowledge
  • Service provider networking knowledge

Overview

We all have our habits that are inherited from our past experience. Some people are used to IOS, IOS-XR, NX-OX, IOS-XE others prefer Junos etc. Using freeRouter provides a different user experience. Some feature such as show/view/watch/differ diagnosis commands are pretty unique to freeRouter. However, freeRouter have some cards in its sleeves in order to provide you a familiar experience.

Article objective

In this article, we will focus on these features:

  • monitor
  • length
  • width
  • spacetab
  • tablemode
  • timestamps
  • colorized

Basically these commands are accessed through freeRouter user mode. If you need to use them from config mode, please use the "do" keyword.

[ #003 ] - "monitor/length/width/spacetab/tablemode/timestamps/colorized"

If you are familiar with Cisco operating system you will feel at home with "terminal monitor" mode. This mode is usually used in combination with "debug" diagnosis command and actually redirect console amd debug output also in your current terminal session. (VTY in Cisco language)

Let's assume we want to debug IPv4 BGP

show BGP configuration from running config
r1#debug proto bgp ?                                                      
  computation - computation events
  event       - table events
  full        - full events
  incremental - incremental events
  traffic     - interface packets

Let's activate BGP debug event

Check BGP IPv4 peers status in VRF dn42
r1#debug rtr.rtrBgpSpeak.packRecv:rtrBgpSpeak.java:1134 got update from 172.23.215.177
debug rtr.rtrBgp.routerCreateComputed:rtrBgp.java:1902 create table
debug rtr.rtrBgpSpeak.packSend:rtrBgpSpeak.java:1080 sending update to 172.23.215.177
r1#                                                                       
r1#debug rtr.rtrBgpSpeak.packRecv:rtrBgpSpeak.java:1134 got keepalive from 172.23.215.177
debug rtr.rtrBgpSpeak.packSend:rtrBgpSpeak.java:1080 sending keepalive to 172.23.215.177
debug rtr.rtrBgpSpeak.packRecv:rtrBgpSpeak.java:1134 got update from fd40:cc1e:c0de::151
debug rtr.rtrBgp.routerCreateComputed:rtrBgp.java:1902 create table
debug rtr.rtrBgpSpeak.packSend:rtrBgpSpeak.java:1080 sending update to fd40:cc1e:c0de::151
debug rtr.rtrBgpSpeak.packRecv:rtrBgpSpeak.java:1134 got update from fd40:cc1e:c0de::151
debug rtr.rtrBgp.routerCreateComputed:rtrBgp.java:1902 create table
debug rtr.rtrBgpSpeak.packRecv:rtrBgpSpeak.java:1134 got update from fd40:cc1e:c0de::151
debug rtr.rtrBgp.routerCreateComputed:rtrBgp.java:1902 create table
debug rtr.rtrBgpSpeak.packSend:rtrBgpSpeak.java:1080 sending update to fd40:cc1e:c0de::151
debug rtr.rtrBgpSpeak.packRecv:rtrBgpSpeak.java:1134 got update from fd40:cc1e:c0de::151
debug rtr.rtrBgp.routerCreateComputed:rtrBgp.java:1902 create table
...

in order to cancel debug:

undebug all (or specific debug)
r1#un all
...

in order to stop console output from your terminal session:

termonal no monitor
r1#term no mon
...

Note

Similar to Cisco gear, "debug" can be very chatty. Therefore, be ready to issue "term no mon" or better log debug into a file for further off-line forensics.

In my previous examples, the output of "show ipv4 bgp 42 unicast database" command could not fit my window as the output as tomany lines. "terminal length" can be used to alter the number of  lines of the terminal.

Check hardware traffic counters
r1##terminal length ?                                                      
  <num> - height in lines

r1#terminal length
...

Note

"terminal length" can have no effect if you are using a more sophisticated terminal. However, this will have a visible impact on view/display/differ buffer.

"terminal spacetab" is specifically decidated to Junos user. It basically does the same effect as the <TAB> key, but it add also contextual completion with the <SPACE>

Check hardware traffic counters
r1#terminal spacetab ?                                                    
  <cr>

r1#terminal spacetab                                                      
...

Note

"terminal spacetab" does not remove <TAB> key behaviour.

"terminal tablemode" provide pre-formatted table output. 

"terminal tablemode" available format
mjolnir#terminal tablemode ?                                                   
  csv    - select csv mode
  fancy  - select fancy mode
  html   - select html mode
  normal - select normal mode
  raw    - select raw mode
  table  - select table mode
r1#terminal spacetab ?                                                    
  <cr>

Let's select "fancy"

Fancy mode
r1#show ipv4 bgp 42 summary                                               
 |~~~~~~~~~~~~|~~~~~~~|~~~~~~|~~~~~~~|~~~~~~~~~~~~~~~~|~~~~~~~~~~|
 | as         | learn | done | ready | neighbor       | uptime   |
 |------------|-------|------|-------|----------------|----------|
 | 4242421955 | 516   | 517  | true  | 172.23.215.177 | 01:16:23 |
 |____________|_______|______|_______|________________|__________|

Note

Feel free to play all format proposed by "terminal tablemode". This is pretty useful when you have to prepare some report related to the VPN or network you are currently managing.

"terminal timestamps" will simply prepend command timestamps.

Fancy mode
r1#show ipv4 bgp 42 summary                                               
2020-09-30 09:46:32
 |~~~~~~~~~~~~|~~~~~~~|~~~~~~|~~~~~~~|~~~~~~~~~~~~~~~~|~~~~~~~~~~|
 | as         | learn | done | ready | neighbor       | uptime   |
 |------------|-------|------|-------|----------------|----------|
 | 4242421955 | 516   | 517  | true  | 172.23.215.177 | 01:18:45 |
 |____________|_______|______|_______|________________|__________|

Note

As you can see, you can stack these modes. Here we activated "terminal tablemode + timestamps"

"terminal colorized" will simply  color  your prompt

"terminal <mode>" is specific to your current session. If you want a persistent behaviour you would need to activate these features from the  "server telnet" stanza. Which as its name wrongly implies, is not about configuring a telnet server only. From this stanza you'll able to configure any type of server dedicated to terminal connection. (SSH)

Fancy mode
r1#(cfg-server)#exec ?                                                     
  authorization - set authorization
  autocommand   - set automatic command
  autohangup    - disconnect user after autocommand
  bye           - set goodbye message
  colorized     - enable colorization
  height        - set height of terminal
  interface     - set interface to use for framing
  logging       - enable logging
  privilege     - set default privilege
  ready         - set ready message
  spacetab      - enable space as tab
  tablemode     - set table mode
  timeout       - set timeout value
  timestamp     - enable timestamps
  welcome       - set welcome message
  width         - number of columns

Note

This "server telnet" section will provide you lots of possibility to fine tune your terminal access !  Feel free to use them in order to feel at home !

Discussion

monitor/length/width/spacetab/tablemode/timestamps/colorized is a set of feature meant to ease your experience with freeRouter in mimic'ing well know behaviour and proposing you additional convenient features. One main behaviour is that all command issue from the CLI is instantly taken into account. 

Conclusion

In this 3rd article:

  • We presented freeRouter monitor/length/width/spacetab/tablemode/timestamps/colorized terminal customization command
  • These are very useful if you come from Cisco or Junos world as it mimic some termnal behaviour.

Final words

As said, these are terminal commands are not specific to freeRouter. Some behaviour are mimic'ed from IOS and Junos. Anyway, these have been developed for one purpose:

"Make network engineers feel at ease and provide then an enjoyable operation experience "

Feel free to try and use them according to your environment taste!

Last but not least, you can play with these different mode from this sandbox:

type "telnet dl.nop.hu" in a terminal and choose "1"
telnet dl.nop.hu
Trying 193.224.23.5...
Connected to dl.nop.hu.
Escape character is '^]'.
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXX XXXXX XXX    XXX     XXX XX XX XXXX XXXXXXXXXXXXXXXXXXX
XXXX  XXXX XX XXXX XX XXXX XX XX XX XXXX XXXXX/~~~~~~\XXXXXX
XXXX X XXX XX XXXX XX XXXX XX XX XX XXXX XXXX| player |XXXXX
XXXX XX XX XX XXXX XX     XXX    XX XXXX XXXXX\______/XXXXXX
XXXX XXX X XX XXXX XX XXXXXXX XX XX XXXX XXXXXXXXXXXXXXXXXXX
XXXX XXXX  XX XXXX XX XXXXXXX XX XX XXXX XXXXXXXXXXXXXXXXXXX
XXXX XXXXX XXX    XXX XXX XXX XX XXX    XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
welcome
line ready
menu lab:
# - reboot router1
$ - reboot router2
% - reboot router3
1 - connect to router1
2 - connect to router2
3 - connect to router3
^ - rebuild routers
l - connect to lg.nop.dn42
x - exit
choose:1 - attach vdc lab1 

welcome
line ready
yourname#terminal ?                                                            
  colorized  - sending to ansi terminal
  length     - set terminal length
  monitor    - log to this terminal
  no         - negate a parameter
  spacetab   - treat space as tabulator
  tablemode  - select table formatting mode
  timestamps - put time before each executed command
  width      - set terminal width

yourname#terminal                            
...

In order to exit the sandbox session use the following escape sequence: Ctrl-c + Ctrl-x