Need help for nftables : nft commands throwing " error - Operation not supported"

Hi everyone,

Request for your kind help related to nftables.

Exploring nft, as part of it i'm trying nft configuration commands.

only nft

tried couple of them i'm getting below error .
Error: Could not process rule: Operation not supported

Debian - 10.

root@localhost:~# uname -a
Linux localhost 4.19.81-OpenNetworkLinux-thanos #1 SMP Tue Apr 28 08:24:05 UTC 2020 x86_64 GNU/Linux

root@localhost:~# nft -v
nftables v0.9.0 (Fearless Fosdick)

Confirmed nft and dependent packages are installed.

root@localhost:~# sudo dpkg-query -l
...
ii libnftables0:amd64 0.9.0-2 amd64 Netfilter nftables high level userspace API library
ii libnftnl11:amd64 1.1.2-2 amd64 Netfilter nftables userspace API library
ii nftables 0.9.0-2 amd64 Program to control packet filtering rules by Netfilter project
ii libmnl0:amd64 1.0.4-2 amd64 minimalistic Netlink communication library
...

Tried below commands:

1) root@localhost:~# nft --debug all flush ruleset

2) root@localhost:~# nft --debug all add table ip filter

Below is the debug output for the above 2) add command

similar "operation unsupported" error was for 1) as well.

"
Entering state 0
Reducing stack by rule 1 (line 747):
-> $$ = nterm input (: )
Stack now 0
Entering state 1
Reading a token: --accepting rule at line 275 ("add")
Next token is token "add" (: )
Shifting token "add" (: )
Entering state 19
Reading a token: --accepting rule at line 631 (" ")
--accepting rule at line 245 ("table")
Next token is token "table" (: )
Shifting token "table" (: )
Entering state 10
Reading a token: --accepting rule at line 631 (" ")
--accepting rule at line 388 ("ip")
Next token is token "ip" (: )
Shifting token "ip" (: )
Entering state 35
Reducing stack by rule 246 (line 1845):
$1 = token "ip" (: )
-> $$ = nterm family_spec_explicit (: )
Stack now 0 1 19 10
Entering state 47
Reducing stack by rule 245 (line 1842):
$1 = nterm family_spec_explicit (: )
-> $$ = nterm family_spec (: )
Reducing stack by rule 245 (line 1842):
$1 = nterm family_spec_explicit (: )
-> $$ = nterm family_spec (: )
Stack now 0 1 19 10
Entering state 46
Reading a token: --accepting rule at line 631 (" ")
--accepting rule at line 602 ("filter")
Next token is token "string" (: )
Shifting token "string" (: )
Entering state 53
Reducing stack by rule 239 (line 1818):
$1 = token "string" (: )
-> $$ = nterm identifier (: )
Stack now 0 1 19 10 46
Entering state 250
Reducing stack by rule 252 (line 1853):
$1 = nterm family_spec (: )
$2 = nterm identifier (: )
-> $$ = nterm table_spec (: )
Stack now 0 1 19 10
Entering state 57
Reading a token: --accepting rule at line 611 ("
")
Next token is token "newline" (: )
Reducing stack by rule 31 (line 874):
$1 = token "table" (: )
$2 = nterm table_spec (: )
-> $$ = nterm add_cmd (: )
Stack now 0 1 19
Entering state 66
Reducing stack by rule 17 (line 858):
$1 = token "add" (: )
$2 = nterm add_cmd (: )
-> $$ = nterm base_cmd (: )
Stack now 0 1
Entering state 44
Next token is token "newline" (: )
Shifting token "newline" (: )
Entering state 4
Reducing stack by rule 3 (line 766):
$1 = token "newline" (: )
-> $$ = nterm stmt_separator (: )
Stack now 0 1 44
Entering state 249
Reducing stack by rule 14 (line 824):
$1 = nterm base_cmd (: )
$2 = nterm stmt_separator (: )
-> $$ = nterm line (: )
Stack now 0 1
Entering state 43
Reducing stack by rule 2 (line 748):
$1 = nterm input (: )
$2 = nterm line (: )

Evaluate add
add table ip filter
^^^^^^^^^^^^^^^^^^^^

-> $$ = nterm input (: )
Stack now 0
Entering state 1
Reading a token: --(end of buffer or a NUL)
--EOF (start condition 0)
Now at end of input.
Shifting token "end of file" (: )
Entering state 2
Stack now 0 1 2
Cleanup: popping token "end of file" (: )
Cleanup: popping nterm input (: )
---------------- ------------------
| 0000000020 | | message length |
| 00016 | R--- | | type | flags |
| 0000000000 | | sequence number|
| 0000000000 | | port ID |
---------------- ------------------
| 00 00 0a 00 | | extra header |"
.....

Error: Could not process rule: Operation not supported
add table ip filter
^^^^^^^^^^^^^^

Appreciate your help.

Thanks all,

Santosh