[MLandi]

[tatsuya46]

so how is this fixed..? cause the build is unusable, no ssh, no telnet, unbound hangs, dnsmasq in some half frozen state..

there no ed25519 anything anywhere in winscp, nothing worked was basically locked out of my own router as downgrading in web ui didnt work, look 3x longer than usual, looked like it was rebooting but it wasnt.. had to use physdiskwrite to fix all of this for x86_64.

[ho1Aetoo]

[Alozaros]

Hi Guys...well im tempted to update my R7800, but there are few questions arising:

-Im using 3072bit RSA ssh-2 key pasted on the router in putty format + custom port and i use putty to connect either from linux or win machines...will ssh work after update with no reset...?
-Will the update keep the currently configured ssh key as it is?
-I also dont have a physical, nor GUI access to the router as i use ssh over the WAN at the moment will ssh work out of the box after the update or i have to fiddle with it...?
-Shall i wait until i get back and have a physical access ?
-If i update would it be possible to fiddle with ssh nvram values before reboot and make it work after the reboot...what exactly i need to do ?
-If i enable telnet over WAN before the update will, i be able to fiddle with the SSh changes and paste the new ssh key in the nvram...after the update ?

y tatsuya46 said no telnet too ??

[ho1Aetoo]

RSA also works, other public keys like Ed25519 or ECDSA also work.

However, the HOST key, i.e. the fingerprint of the router, has changed.

You don't have to reset the router if programs don't want to connect via SSH anymore because another HOST key (fingerprint) is stored.

Here in the thread is described several times how to delete the stored fingerprint under Linux or Windows.

As a suggestion, just activate Telnet briefly.
If you get no ssh access for a short time you can still log in via telnet and check which public key is stored in the nvram.

It's not that complicated ... actually you only have to remove the old fingerprints from the "known_hosts" - then ssh access works.

[Alozaros]

[ho1Aetoo]

Sorry no idea what this has to do with telnet.
Telnet works exactly like ssh

[Alozaros]

well im doing things over the WAN, so telnet is a bad plan..for remote access as its a crap and not encrypted...so ill need to change the router password after i use it i guess...

as well tatsuya46 mentioned above on that build no telnet whatever that means...


the thing is i dont want to end up with no access to the unit and have telnet over the WAN left on...

[ho1Aetoo]

Yes I mean only the changes affect only ssh.
Telnet does not use host key etc

[Alozaros]

[strange]

I'm running linux. It appears that the simplest thing to do is to delete my host file and reconnect to my devices if I run into any connection issues with my xr500. Does that sound right?

[ho1Aetoo]

Yes either delete the .ssh/known_host or just the router entry.

If you connect with "ssh root@192.186.1.1" you can delete the entry with "ssh-keygen -R 192.168.1.1"...

depending on the case, with another IP or with the hostname

[Alozaros]

well on the router side the nvram value shows (on my router this looks exactly as i posted below..)

sshd_rsa_host_key=-----BEGIN RSA PRIVATE KEY-----

is this correct? and on update this will be replaced with this i guess with no value

sshd_ed25519_host_key=

does this mean i need to generate and paste an ed25519 key instead of rsa
or the current nvram rsa value will stay as well..as well the old

sshd_authorized_keys=....

i guess im asking too much questions..and it gets confusing..

can anyone post the output of (50906) delete the private data
nvram show | grep ssh

[ho1Aetoo]

as already said several times, the HOST key is the fingerprint of the router.

The host key is only used for identification.

An ed25519 host key also works with a public RSA key.

[Alozaros]