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ssh to 2350 routers result in (derive_ssh1_session_id: bad server modulus (len 48) mesages

09.21.09   |  
‎09-21-2009 12:16 AM

Hi all,

 

I generated a identity  as described:

 

[mbp1@tftp .ssh]$ ssh-keygen -b 1024 -t rsa1
Generating public/private rsa1 key pair.
Enter file in which to save the key (/home/mbp1/.ssh/identity):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/mbp1/.ssh/identity.
Your public key has been saved in /home/mbp1/.ssh/identity.pub.
The key fingerprint is:
1d:cf:65:37:37:d0:63:13:ea:ea:7c:7c:52:6d:a3:19

 

loaded this in the router:

root@2350-1# set system root-authentication load-key-file identity.pub  ( and commit)

 

now when I try to ssh to this router I get the following error:

 

[mbp1@tftp .ssh]$ ssh -v -l root -1 172.30.6.52
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 172.30.6.52 [172.30.6.52] port 22.
debug1: Connection established.
debug1: identity file /home/mbp1/.ssh/identity type 0
debug1: loaded 1 keys
debug1: Remote protocol version 1.5, remote software version OpenSSH_4.4
debug1: match: OpenSSH_4.4 pat OpenSSH*
debug1: Local version string SSH-1.5-OpenSSH_4.3
debug1: Waiting for server public key.
debug1: Received server public key (384 bits) and host key (512 bits).
The authenticity of host '172.30.6.52 (172.30.6.52)' can't be established.
RSA1 key fingerprint is c1:ef:af:f7:c4:7b:5a:98:28:42:ea:ca:28:14:a0:85.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.30.6.52' (RSA1) to the list of known hosts.
derive_ssh1_session_id: bad server modulus (len 48)

 

Has anyone any Idea what went wrong ? (juniper to juniper is working well)

 

 

Thanks in advance,

Michel

5 REPLIES
Junos

Re: ssh to 2350 routers result in (derive_ssh1_session_id: bad server modulus (len 48) mesages

09.21.09   |  
‎09-21-2009 12:38 AM

Hi,

 

it seems to be a known issue with Export software version. Please install Domestic Junos version (strong encryption) and you should not see this problem again. 

 

If this worked for you please flag my post as an "Accepted Solution" so others can benefit. A kudo would be cool if you think I earned it. 

 

Kind Regards

Michael Pergament

Junos
Solution
Accepted by topic author Mickey
‎08-26-2015 01:27 AM

Re: ssh to 2350 routers result in (derive_ssh1_session_id: bad server modulus (len 48) mesages

10.27.09   |  
‎10-27-2009 07:53 AM

It took a while for Juniper to figure it out but the solution is to remove everthing from the .ssh directory on the juniper after the key is installed.

Junos

Re: ssh to 2350 routers result in (derive_ssh1_session_id: bad server modulus (len 48) mesages

[ Edited ]
11.17.09   |  
‎11-17-2009 12:38 AM

Hi, I got also "derive_ssh1_session_id: bad server modulus (len 48)" when I try to login from my debian to a J6350.

My .ssh directory is empty.. any ideas?

 

hostname:~# ssh 172.16.1.130 -l usaername -v -1

OpenSSH_5.1p1 Debian-5, OpenSSL 0.9.8g 19 Oct 2007

debug1: Reading configuration data /etc/ssh/ssh_config debug1: Applying options for *

debug1: Connecting to 172.16.1.130 [172.16.1.130] port 22. debug1: Connection established.

debug1: permanently_set_uid: 0/0 debug1: identity file /root/.ssh/identity type -1

debug1: Remote protocol version 1.5, remote software version OpenSSH_4.4

debug1: match: OpenSSH_4.4 pat OpenSSH_4*

debug1: Local version string SSH-1.5-OpenSSH_5.1p1 Debian-5 debug1: Waiting for server public key.

debug1: Received server public key (384 bits) and host key (512 bits).

debug1: Host '172.16.1.130' is known and matches the RSA1 host key.

debug1: Found key in /root/.ssh/known_hosts:15

derive_ssh1_session_id: bad server modulus (len 48)

Junos

Re: ssh to 2350 routers result in (derive_ssh1_session_id: bad server modulus (len 48) mesages

11.17.09   |  
‎11-17-2009 12:41 AM

Hi,

 

you have export version without strong encryption. Please install Domestic Junos version.

 

Kind Regards

Michael Pergament

Junos

Re: ssh to 2350 routers result in (derive_ssh1_session_id: bad server modulus (len 48) mesages

07.22.10   |  
‎07-22-2010 10:06 AM

Hi,

 

Just to say, I had the exact same problem, I've just upgraded to 9.6R4.4 domestic and am now able to ssh to my J2350.

 

Thanks !