Enhancement - Cisco - add support for if a VRF does not exist

[vv0bbLeS]

My current TextFSM version: 2.1.0
My current ntc-templates version: 8.0.0

Many Cisco switches have commands with a vrf parameter, such as show ip arp or show ip route , and if you pass a VRF that doesn't exist on the switch, the switch will let you know:

Switch1#show ip arp vrf CAMERAS
% VRF CAMERAS does not exist.
Switch1#
Switch1#
Switch1#show ip route vrf CAMERAS
% IP routing table vrf CAMERAS does not exist
Switch1#

However, these output lines of the VRF not existing are not supported in TextFSM 2.1.0, and results in an error:

  File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\clitable.py", line 278, in ParseCmd
    self.table = self._ParseCmdItem(self.raw, template_file=template_files[0])
                 ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\clitable.py", line 312, in _ParseCmdItem
    for record in fsm.ParseText(cmd_input):
                  ~~~~~~~~~~~~~^^^^^^^^^^^
  File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\parser.py", line 912, in ParseText
    self._CheckLine(line)
    ~~~~~~~~~~~~~~~^^^^^^
  File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\parser.py", line 961, in _CheckLine
    if self._Operations(rule, line):
       ~~~~~~~~~~~~~~~~^^^^^^^^^^^^
  File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\parser.py", line 1043, in _Operations
    raise TextFSMError(
    ...<2 lines>...
    )
textfsm.parser.TextFSMError: State Error raised. Rule Line: 15. Input Line: % VRF CAMERAS does not exist.

Can we add support to handle this switch output if a given VRF does not exist on a switch? The outputs seem to all carry the string vrf [x] does not exist.

[harro]

Looks like a straight forward template change rather than a change in TextFSM per se. As I see it, you can parse the error message silently parsing, or by throwing a TextFSM error. Alternatively you could make no changes and catch the TextFSM exception and handle it in your Python script - as calls to a non-existent vrf may be something you want to know about?

…

On Wed, 27 Aug 2025, 3:36 am vv0bbLeS, ***@***.***> wrote: *vv0bbLeS* created an issue (google/textfsm#136) <#136> My current TextFSM version: 2.1.0 My current ntc-templates version: 8.0.0 Many Cisco switches have commands with a vrf parameter, such as show ip arp or show ip route , and if you pass a VRF that doesn't exist on the switch, the switch will let you know: Switch1#show ip arp vrf CAMERAS % VRF CAMERAS does not exist. Switch1# Switch1# Switch1#show ip route vrf CAMERAS % IP routing table vrf CAMERAS does not exist Switch1# However, these output lines of the VRF not existing are not supported in TextFSM 2.1.0, and results in an error: File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\clitable.py", line 278, in ParseCmd self.table = self._ParseCmdItem(self.raw, template_file=template_files[0]) ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\clitable.py", line 312, in _ParseCmdItem for record in fsm.ParseText(cmd_input): ~~~~~~~~~~~~~^^^^^^^^^^^ File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\parser.py", line 912, in ParseText self._CheckLine(line) ~~~~~~~~~~~~~~~^^^^^^ File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\parser.py", line 961, in _CheckLine if self._Operations(rule, line): ~~~~~~~~~~~~~~~~^^^^^^^^^^^^ File "C:\Users\JohnDoe\AppData\Local\Programs\Python\Python313\Lib\site-packages\textfsm\parser.py", line 1043, in _Operations raise TextFSMError( ...<2 lines>... ) textfsm.parser.TextFSMError: State Error raised. Rule Line: 15. Input Line: % VRF CAMERAS does not exist. Can we add support to handle this switch output if a given VRF does not exist on a switch? The outputs seem to all carry the string vrf [x] does not exist. — Reply to this email directly, view it on GitHub <#136>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADD2VEU5POTUSNXTXBBO6LT3PSLJ7AVCNFSM6AAAAACE3XXAXSVHI2DSMVQWIX3LMV43ASLTON2WKOZTGM2TMNJTGY3TQMA> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[vv0bbLeS]

hmm, so I do currently use the TextFSMError class from textfsm.parser to catch any TextFSM errors, but when I encounter a TextFSMError it signals to me that something very wrong happened, or some very weird output was generated.

In this case, the output is seemingly normal output - it's just telling me that a VRF doesn't exist.

• If that output string was added to the template, then TextFSM would treat it as a "normal" result and then I could just add logic on my side to account for that.
• On the other hand, if we leave it as a TextFSMError , I would need to parse the TextFSMError message and look for the "VRF does not exist" string, but that seems kind of messy and against the "spirit" of a TextFSMError .

So I guess in the end this becomes more of a "philosophy" question - for me for something like this, I would rather TextFSM not throw an error, but give me the plain result that I can parse on my side. :)