NVRAM Help Please

[Nogi]

Hello,
I recently upgraded to 384.19 and now have a NVRAM warning. I have searched the forum and I see this may just be coincidental reference the upgrade in firmware and users have this from time to time.

I found a thread that stated to run this command: nvram show | awk '{print length(), $0 | "sort -n -r"}' | cut -d"=" -f 1 | head -n 20

And here is the output, can anyone assist on my next step please?

size: 65438 bytes (98 left)
4813 MULTIFILTER_TMP_T
1407 custom_clientlist
1089 sshd_hostkey
810 nc_setting_conf
624 sshd_dsskey
544 rc_support
338 sshd_ecdsakey
269 client_info_tmp
233 wl1_acs_excl_chans_base
228 wl1_acs_excl_chans
227 wl_acs_excl_chans
205 wl1_chansps
176 dhcp_staticlist
168 dhcp_hostnames
120 qos_rulelist
92 1:pa5ga2
92 1:pa5ga1
92 1:pa5ga0
80 asus_device_list
71 vpn_server2_ncp_ciphers

I am running a MAC so used terminal to SSH in. I have also found another script to try and run, but I don't know how to upload it using a MAC and tutorials mention using WinSCP which is a windows app.

This seems high? 4813 MULTIFILTER_TMP_T (seems to be related to scheduling if I am correct from reading other posts, but I don't use any scheduling)

Any advice appreciated. Thank you

 

[ColinTaylor]

That variable seems to be used by Parental Control. I suggest you just delete it (as is sounds like a temporary variable).

nvram unset MULTIFILTER_TMP_T
nvram commit

 

[L&LD]

What router is this?

 

[Nogi]

What router is this?

Hello,
This is a RT-AC68U

 

[Nogi]

That variable seems to be used by Parental Control. I suggest you just delete it (as is sounds like a temporary variable).

nvram unset MULTIFILTER_TMP_T
nvram commit

I will try this in a minute thanks.

Any other suggestions anyone?

 

[Nogi]

That variable seems to be used by Parental Control. I suggest you just delete it (as is sounds like a temporary variable).

nvram unset MULTIFILTER_TMP_T
nvram commit

So after running those two commands my output looks like so:

size: 60657 bytes (4879 left)
1407 custom_clientlist
1089 sshd_hostkey
810 nc_setting_conf
624 sshd_dsskey
544 rc_support
338 sshd_ecdsakey
269 client_info_tmp
233 wl1_acs_excl_chans_base
228 wl1_acs_excl_chans
227 wl_acs_excl_chans
205 wl1_chansps
176 dhcp_staticlist
168 dhcp_hostnames
120 qos_rulelist
92 1:pa5ga2
92 1:pa5ga1
92 1:pa5ga0
80 asus_device_list
71 vpn_server2_ncp_ciphers
71 vpn_server1_ncp_ciphers

and the NVRAM warning has gone. I have also rebooted the router to see if a reboot changed anything and the system isn't warning me anymore.

Does it matter that I removed or deleted something with that command? the next TWO larger values in that output does anyone know if I should be looking at deleting or streamlining them?

1407 custom_clientlist
1089 sshd_hostkey

I assume they are to do with my Clients Names or Icons I have set? and my OpenVPN connections? only have 1 VPN I run periodically.

Any explanations for my own knowledge and further instances of the NVRAM warning being low would be good.

@ColinTaylor and @L&LD thank you for replying so far.

 

[Nogi]

I've also used nano to create a script in the scripts folder and ran this:

#!/bin/sh

    echo "Removing unused cert/key from nvram..."

    for i in 1 2 3 4 5
    do
       nvram unset vpn_crt_client$i\_ca
       nvram unset vpn_crt_client$i\_extra
       nvram unset vpn_crt_client$i\_crt
       nvram unset vpn_crt_client$i\_key
       nvram unset vpn_crt_client$i\_crl
       nvram unset vpn_crt_client$i\_static
    done

    for i in 1 2
    do
       nvram unset vpn_crt_server$i\_ca
       nvram unset vpn_crt_server$i\_dh
       nvram unset vpn_crt_server$i\_ca_key
       nvram unset vpn_crt_server$i\_extra
       nvram unset vpn_crt_server$i\_client_crt
       nvram unset vpn_crt_server$i\_crl
       nvram unset vpn_crt_server$i\_crt
       nvram unset vpn_crt_server$i\_key
       nvram unset vpn_crt_server$i\_static
       nvram unset vpn_crt_server$i\_client_key
    done

    nvram commit

    echo "done."

Going to stop messing now unless someone suggests something as I have no idea what im doing

 

[ColinTaylor]

So after running those two commands my output looks like so:

size: 60657 bytes (4879 left)
:
:

Your NVRAM is fine now. No need to mess about with it any further.

FYI I think the creation of the MULTIFILTER_TMP_T variable is actually a bug as it doesn't appear to be used by the firmware at all, and normally doesn't exist.

 

[Nogi]

Your NVRAM is fine now. No need to mess about with it any further.

FYI I think the creation of the MULTIFILTER_TMP_T variable is actually a bug as it doesn't appear to be used by the firmware at all, and normally doesn't exist.

Thanks after running the other script to clear unused vpn certs my size is now:

size: 59547 bytes (5989 left)

So looks like these steps did the job. Would be nice to know why the MULTIFILTER_TMP_T variable got so large but anyway, thanks for your assistance

 

[dave14305]

1089 sshd_hostkey
624 sshd_dsskey
338 sshd_ecdsakey

I am 99% sure these particular ssh vars are obsolete in Merlin since 2017. The keys are stored in /jffs/.cert now.

ssh: store keys in /jffs/ to work around 1000 bytes limitation, and s… · RMerl/asuswrt-merlin.ng@8b800ea

…ave on nvram This fixes HND devices that would generate a new hostkey every reboot, as the router was unable to store the hostkey in nvram.

github.com