SSH connection error

[tedauction]

Hello, I am running the following:

WS-C2960CG-8TC-L   12.2(55)EX2

I cannot connect via SSH. I receive the following error logs. Does anyone have any suggestions ?

I have re-generated the keys to no avail. I am thinking perhaps the first key exchange algoritim 'diffie-hellman-group1-sha1' is to old for the SSH client I am connecting from ?

Thank you kindly for any information.

mySwitch# sh ip ssh
SSH Enabled - version 2.0
Authentication timeout: 120 secs; Authentication retries: 3
 

mySwitch#sh ver
Cisco IOS Software, C2960C Software (C2960c405ex-UNIVERSALK9-M), Version 12.2(55)EX2, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Wed 18-May-11 14:42 by prod_rel_team
Image text-base: 0x00003000, data-base: 0x01B00000

ROM: Bootstrap program is C2960C boot loader
BOOTLDR: C2960C Boot Loader (C2960C-HBOOT-M) Version 12.2(55r)EX11, RELEASE SOFTWARE (fc1)

MoreNewsBth uptime is 3 years, 34 weeks, 5 days, 22 hours, 48 minutes
System returned to ROM by power-on
System restarted at 13:17:17 NZST Thu Aug 28 2014
System image file is "flash:/c2960c405ex-universalk9-mz.122-55.EX2/c2960c405ex-universalk9-mz.122-55.EX2.bin"

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
--More--
Apr 28 12:13:29: %SYS-5-CONFIG_I: Configured from console by lastresort on vty0 (10compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

License Level: lanbase
License Type: Permanent
Next reload license Level: lanbase

cisco WS-C2960CG-8TC-L (PowerPC) processor (revision E0) with 131072K bytes of memory.
Processor board ID FOC1809Y12Q
Last reset from power-on
3 Virtual Ethernet interfaces
10 Gigabit Ethernet interfaces
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address : 2C:3E:CF:6B:88:80
Motherboard assembly number : 73-13271-07
Power supply part number : 341-0208-02
Motherboard serial number : FOC18083230
Power supply serial number : LIT18040RR0
Model revision number : E0
Motherboard revision number : A0
Model number : WS-C2960CG-8TC-L
System serial number : FOC1809Y12Q
Top Assembly Part Number : 800-33673-03
Top Assembly Revision Number : B0
Version ID : V03
CLEI Code Number : CMMDJ10ARC
Hardware Board Revision Number : 0x00

Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 10 WS-C2960CG-8TC-L 12.2(55)EX2 C2960c405ex-UNIVERSALK9-M

OUTPUT OF DEBUG IP SSH: 

Apr 28 00:15:49.484: SSH1: starting SSH control process
Apr 28 00:15:49.484: SSH1: sent protocol version id SSH-2.0-Cisco-1.25
Apr 28 00:15:49.489: SSH1: protocol version id is - SSH-2.0-OpenSSH_5.3
Apr 28 00:15:49.489: SSH2 1: send: len 280 (includes padlen 4)
Apr 28 00:15:49.489: SSH2 1: SSH2_MSG_KEXINIT sent
Apr 28 00:15:49.494: SSH2 1: ssh_receive: 864 bytes received
Apr 28 00:15:49.494: SSH2 1: input: packet len 864
Apr 28 00:15:49.494: SSH2 1: partial packet 8, need 856, maclen 0
Apr 28 00:15:49.494: SSH2 1: input: padlen 10
Apr 28 00:15:49.494: SSH2 1: received packet type 20
Apr 28 00:15:49.494: SSH2 1: SSH2_MSG_KEXINIT received
Apr 28 00:15:49.494: SSH2: kex: client->server aes128-cbc hmac-sha1 none
Apr 28 00:15:49.494: SSH2: kex: server->client aes128-cbc hmac-sha1 none
Apr 28 00:15:49.526: SSH2 1: expecting SSH2_MSG_KEXDH_INIT
Apr 28 00:15:49.704: SSH2 1: ssh_receive: 144 bytes received
Apr 28 00:15:49.704: SSH2 1: input: packet len 144
Apr 28 00:15:49.704: SSH2 1: partial packet 8, need 136, maclen 0
Apr 28 00:15:49.704: SSH2 1: input: padlen 6
Apr 28 00:15:49.704: SSH2 1: received packet type 30
Apr 28 00:15:49.704: SSH2 1: SSH2_MSG_KEXDH_INIT received
Apr 28 00:15:49.835: SSH2 1: signature length 143
Apr 28 00:15:49.835: SSH2 1: send: len 448 (includes padlen 8)
Apr 28 00:15:49.835: SSH2: kex_derive_keys complete
Apr 28 00:15:49.835: SSH2 1: send: len 16 (includes padlen 10)
Apr 28 00:15:49.835: SSH2 1: newkeys: mode 1
Apr 28 00:15:49.835: SSH2 1: SSH2_MSG_NEWKEYS sent
Apr 28 00:15:49.835: SSH2 1: waiting for SSH2_MSG_NEWKEYS
Apr 28 00:15:49.840: SSH2 1: ssh_receive: 16 bytes received
Apr 28 00:15:49.846: SSH2 1: input: packet len 16
Apr 28 00:15:49.846: SSH2 1: partial packet 8, need 8, maclen 0
Apr 28 00:15:49.846: SSH2 1: input: padlen 10
Apr 28 00:15:49.846: SSH2 1: newkeys: mode 0
Apr 28 00:15:49.846: SSH2 1: received packet type 21
Apr 28 00:15:49.846: SSH2 1: SSH2_MSG_NEWKEYS received
Apr 28 00:15:50.055: SSH2 1: ssh_receive: 52 bytes received
Apr 28 00:15:50.055: SSH2 1: input: packet len 32
Apr 28 00:15:50.055: SSH2 1: partial packet 16, need 16, maclen 20
Apr 28 00:15:50.055: SSH2 1: MAC #3 ok
Apr 28 00:15:50.061: SSH2 1: input: padlen 10
Apr 28 00:15:50.061: SSH2 1: received packet type 5
Apr 28 00:15:50.061: SSH2 1: send: len 32 (includes padlen 10)
Apr 28 00:15:50.061: SSH2 1: done calc MAC out #3
Apr 28 00:15:50.061: SSH2 1: send: len 656 (includes padlen 7)
Apr 28 00:15:50.061: SSH2 1: done calc MAC out #4
Apr 28 00:15:50.066: SSH2 1: ssh_receive: 84 bytes received
Apr 28 00:15:50.066: SSH2 1: input: packet len 64
Apr 28 00:15:50.066: SSH2 1: partial packet 16, need 48, maclen 20
Apr 28 00:15:50.066: SSH2 1: MAC #4 ok
Apr 28 00:15:50.344: SSH2 1: env request
Apr 28 00:15:50.344: SSH2 1: input: packet len 32
Apr 28 00:15:50.344: SSH2 1: partial packet 16, need 16, maclen 20
Apr 28 00:15:50.344: SSH2 1: MAC #10 ok
Apr 28 00:15:50.344: SSH2 1: input: padlen 12
Apr 28 00:15:50.344: SSH2 1: received packet type 98
Apr 28 00:15:50.344: SSH2 1: send: len 16 (includes padlen 6)
Apr 28 00:15:50.344: SSH2 1: done calc MAC out #10
Apr 28 00:15:50.344: SSH2 1: shell request
Apr 28 00:15:50.344: SSH2 1: shell message received
Apr 28 00:15:50.344: SSH2 1: starting shell for vty
Apr 28 00:15:50.344: SSH2 1: send: len 32 (includes padlen 4)
Apr 28 00:15:50.344: SSH2 1: done calc MAC out #11
Apr 28 00:15:50.428: SSH2 1: ssh_receive: 52 bytes received
Apr 28 00:15:50.438: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:50.438: SSH2 0: done calc MAC out #940
Apr 28 00:15:50.443: SSH2 1: input: packet len 32
Apr 28 00:15:50.443: SSH2 1: partial packet 16, need 16, maclen 20
Apr 28 00:15:50.443: SSH2 1: MAC #11 ok
Apr 28 00:15:50.443: SSH2 1: input: padlen 17
Apr 28 00:15:50.443: SSH2 1: received packet type 94
Apr 28 00:15:50.443: SSH2 1: send: len 32 (includes padlen 16)
Apr 28 00:15:50.443: SSH2 1: done calc MAC out #12
Apr 28 00:15:50.443: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:50.449: SSH2 0: done calc MAC out #941
Apr 28 00:15:50.449: SSH2 1: send: len 32 (includes padlen 6)
Apr 28 00:15:50.449: SSH2 1: done calc MAC out #13
Apr 28 00:15:50.449: SSH2 0: send: len 832 (includes padlen 5)
Apr 28 00:15:50.449: SSH2 0: done calc MAC out #942
Apr 28 00:15:50.506: SSH2 1: ssh_receive: 52 bytes received
Apr 28 00:15:50.517: SSH2 1: input: packet len 32
Apr 28 00:15:50.517: SSH2 1: partial packet 16, need 16, maclen 20
Apr 28 00:15:50.517: SSH2 1: MAC #12 ok
Apr 28 00:15:50.517: SSH2 1: input: padlen 17
Apr 28 00:15:50.517: SSH2 1: received packet type 94
Apr 28 00:15:50.517: SSH2 1: send: len 32 (includes padlen 16)
Apr 28 00:15:50.517: SSH2 1: done calc MAC out #14
Apr 28 00:15:50.522: SSH2 1: send: len 32 (includes padlen 6)
Apr 28 00:15:50.522: SSH2 1: done calc MAC out #15
Apr 28 00:15:50.627: SSH2 1: ssh_receive: 68 bytes received
Apr 28 00:15:50.632: SSH2 1: input: packet len 48
Apr 28 00:15:50.632: SSH2 1: partial packet 16, need 32, maclen 20
Apr 28 00:15:50.632: SSH2 1: MAC #13 ok
Apr 28 00:15:50.632: SSH2 1: input: padlen 16
Apr 28 00:15:50.632: SSH2 1: received packet type 94
Apr 28 00:15:50.632: SSH2 1: send: len 32 (includes padlen 17)
Apr 28 00:15:50.632: SSH2 1: done calc MAC out #16
Apr 28 00:15:50.637: SSH2 1: send: len 32 (includes padlen 17)
Apr 28 00:15:50.637: SSH2 1: done calc MAC out #17
Apr 28 00:15:50.637: SSH2 1: send: len 32 (includes padlen 17)
Apr 28 00:15:50.989: SSH2 1: send: len 1056 (includes padlen 18)
Apr 28 00:15:50.989: SSH2 1: done calc MAC out #49
Apr 28 00:15:51.072: SSH2 1: send: len 832 (includes padlen 19)
Apr 28 00:15:51.072: SSH2 1: done calc MAC out #50
Apr 28 00:15:51.104: SSH2 1: ssh_receive: 52 bytes received
Apr 28 00:15:51.104: SSH2 1: input: packet len 32
Apr 28 00:15:51.104: SSH2 1: partial packet 16, need 16, maclen 20
Apr 28 00:15:51.104: SSH2 1: MAC #15 ok
Apr 28 00:15:51.104: SSH2 1: input: padlen 17
Apr 28 00:15:51.104: SSH2 1: received packet type 94
Apr 28 00:15:51.104: SSH2 1: send: len 32 (includes padlen 17)
Apr 28 00:15:51.109: SSH2 1: done calc MAC out #51
Apr 28 00:15:51.460: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:51.460: SSH2 0: done calc MAC out #943
Apr 28 00:15:51.466: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:51.466: SSH2 0: done calc MAC out #944
Apr 28 00:15:51.471: SSH2 0: send: len 736 (includes padlen 8)
Apr 28 00:15:51.471: SSH2 0: done calc MAC out #945
Apr 28 00:15:51.550: SSH2 0: ssh_receive: 120 bytes received
Apr 28 00:15:51.560: SSH2 0: input: packet len 16
Apr 28 00:15:51.560: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:51.560: SSH2 0: MAC #1277 ok
Apr 28 00:15:51.560: SSH2 0: input: padlen 6
Apr 28 00:15:51.560: SSH2 0: received packet type 2
Apr 28 00:15:51.560: SSH2 0: input: packet len 64
Apr 28 00:15:51.560: SSH2 0: partial packet 16, need 48, maclen 20
Apr 28 00:15:51.560: SSH2 0: MAC #1278 ok
Apr 28 00:15:51.560: SSH2 0: input: padlen 15
Apr 28 00:15:51.560: SSH2 0: received packet type 98
Apr 28 00:15:51.560: SSH2 0: send: len 16 (includes padlen 6)
Apr 28 00:15:51.560: SSH2 0: done calc MAC out #946
Apr 28 00:15:51.560: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:51.560: SSH2 0: input: packet len 16
Apr 28 00:15:51.560: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:51.560: SSH2 0: MAC #1279 ok
Apr 28 00:15:51.560: SSH2 0: input: padlen 6
Apr 28 00:15:51.560: SSH2 0: received packet type 2
Apr 28 00:15:51.560: SSH2 0: input: packet len 32
Apr 28 00:15:51.560: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:51.560: SSH2 0: MAC #1280 ok
Apr 28 00:15:51.560: SSH2 0: input: padlen 18
Apr 28 00:15:51.560: SSH2 0: received packet type 93
Apr 28 00:15:51.560: SSH2 0: channel window adjust message received 8510
Apr 28 00:15:52.472: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:52.472: SSH2 0: done calc MAC out #947
Apr 28 00:15:52.483: SSH2 0: send: len 992 (includes padlen 5)
Apr 28 00:15:52.483: SSH2 0: done calc MAC out #948
Apr 28 00:15:53.489: SSH2 0: send: len 656 (includes padlen 16)
Apr 28 00:15:53.489: SSH2 0: done calc MAC out #949
Apr 28 00:15:55.503: SSH2 0: send: len 144 (includes padlen 12)
Apr 28 00:15:55.503: SSH2 0: done calc MAC out #950no d
Apr 28 00:15:57.516: SSH2 0: send: len 144 (includes padlen 12)
Apr 28 00:15:57.516: SSH2 0: done calc MAC out #951
Apr 28 00:15:58.088: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.088: SSH2 0: input: packet len 16
Apr 28 00:15:58.088: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.088: SSH2 0: MAC #1281 ok
Apr 28 00:15:58.088: SSH2 0: input: padlen 6
Apr 28 00:15:58.088: SSH2 0: received packet type 2
Apr 28 00:15:58.088: SSH2 0: input: packet len 32
Apr 28 00:15:58.088: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.088: SSH2 0: MAC #1282 ok
Apr 28 00:15:58.093: SSH2 0: input: padlen 17
Apr 28 00:15:58.093: SSH2 0: received packet type 94
Apr 28 00:15:58.093: SSH2 0: send: len 32 (includes padlen 17)
Apr 28 00:15:58.093: SSH2 0: done calc MAC out #952
Apr 28 00:15:58.145: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.145: SSH2 0: input: packet len 16
Apr 28 00:15:58.150: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.150: SSH2 0: MAC #1283 ok
Apr 28 00:15:58.150: SSH2 0: input: padlen 6
Apr 28 00:15:58.150: SSH2 0: received packet type 2
Apr 28 00:15:58.150: SSH2 0: input: packet len 32
Apr 28 00:15:58.150: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.150: SSH2 0: MAC #1284 ok
Apr 28 00:15:58.150: SSH2 0: input: padlen 17
Apr 28 00:15:58.150: SSH2 0: received packet type 94
Apr 28 00:15:58.150: SSH2 0: send: len 32 (includes padlen 17)
Apr 28 00:15:58.150: SSH2 0: done calc MAC out #953
Apr 28 00:15:58.208: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.208: SSH2 0: input: packet len 16
Apr 28 00:15:58.208: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.208: SSH2 0: MAC #1285 ok
Apr 28 00:15:58.208: SSH2 0: input: padlen 6
Apr 28 00:15:58.208: SSH2 0: received packet type 2
Apr 28 00:15:58.208: SSH2 0: input: packet len 32
Apr 28 00:15:58.208: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.213: SSH2 0: MAC #1286 ok
Apr 28 00:15:58.213: SSH2 0: input: padlen 17
Apr 28 00:15:58.213: SSH2 0: received packet type 94
Apr 28 00:15:58.213: SSH2 0: send: len 32 (includes padlen 17)
Apr 28 00:15:58.213: SSH2 0: done calc MAC out #954
Apr 28 00:15:58.339: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.339: SSH2 0: input: packet len 16
Apr 28 00:15:58.339: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.339: SSH2 0: MAC #1287 ok
Apr 28 00:15:58.339: SSH2 0: input: padlen 6
Apr 28 00:15:58.339: SSH2 0: received packet type 2
Apr 28 00:15:58.339: SSH2 0: input: packet len 32ebug all
Apr 28 00:15:58.339: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.339: SSH2 0: MAC #1288 ok
Apr 28 00:15:58.339: SSH2 0: input: padlen 17
Apr 28 00:15:58.339: SSH2 0: received packet type 94
Apr 28 00:15:58.339: SSH2 0: send: len 32 (includes padlen 17)
Apr 28 00:15:58.339: SSH2 0: done calc MAC out #955
Apr 28 00:15:58.523: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.533: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:58.533: SSH2 0: done calc MAC out #956
Apr 28 00:15:58.538: SSH2 0: send: len 1056 (includes padlen 18)
Apr 28 00:15:58.538: SSH2 0: done calc MAC out #957
Apr 28 00:15:58.544: SSH2 0: send: len 576 (includes padlen 17)
Apr 28 00:15:58.544: SSH2 0: done calc MAC out #958
Apr 28 00:15:58.580: SSH2 0: input: packet len 16
Apr 28 00:15:58.580: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.580: SSH2 0: MAC #1289 ok
Apr 28 00:15:58.580: SSH2 0: input: padlen 6
Apr 28 00:15:58.580: SSH2 0: received packet type 2
Apr 28 00:15:58.586: SSH2 0: input: packet len 32
Apr 28 00:15:58.586: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.586: SSH2 0: MAC #1290 ok
Apr 28 00:15:58.586: SSH2 0: input: padlen 17
Apr 28 00:15:58.586: SSH2 0: received packet type 94
Apr 28 00:15:58.586: SSH2 0: send: len 32 (includes padlen 17)
Apr 28 00:15:58.586: SSH2 0: done calc MAC out #959
Apr 28 00:15:58.711: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.717: SSH2 0: input: packet len 16
Apr 28 00:15:58.717: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.717: SSH2 0: MAC #1291 ok
Apr 28 00:15:58.717: SSH2 0: input: padlen 6
Apr 28 00:15:58.717: SSH2 0: received packet type 2
Apr 28 00:15:58.717: SSH2 0: input: packet len 32
Apr 28 00:15:58.717: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.717: SSH2 0: MAC #1292 ok
Apr 28 00:15:58.717: SSH2 0: input: padlen 17
Apr 28 00:15:58.717: SSH2 0: received packet type 94
Apr 28 00:15:58.717: SSH2 0: send: len 32 (includes padlen 17)
Apr 28 00:15:58.717: SSH2 0: done calc MAC out #960
Apr 28 00:15:58.916: SSH2 0: ssh_receive: 88 bytes received
Apr 28 00:15:58.921: SSH2 0: input: packet len 16
Apr 28 00:15:58.921: SSH2 0: partial packet 16, need 0, maclen 20
Apr 28 00:15:58.921: SSH2 0: MAC #1293 ok
Apr 28 00:15:58.921: SSH2 0: input: padlen 6
Apr 28 00:15:58.921: SSH2 0: received packet type 2
Apr 28 00:15:58.921: SSH2 0: input: packet len 32
Apr 28 00:15:58.921: SSH2 0: partial packet 16, need 16, maclen 20
Apr 28 00:15:58.921: SSH2 0: MAC #1294 ok
Apr 28 00:15:58.921: SSH2 0: input: padlen 17
Apr 28 00:15:58.921: SSH2 0: received packet type 94
Apr 28 00:15:58.921: SSH2 0: send: len 32 (includes padlen 17)

[Reza Sharifi]

Hi,

Can you post the output of "sh ver" and "sh ip ssh"? 

HTH

[tedauction]

Thanks Reza, I have update the first post with that information.

[cofee]

Is there any firewall in between? Making sure issue is not related to asymmetric routing. 

[Reza Sharifi]

Hi,

From the output you posted, it does not appear that you have generated the rsa key.

have a look at this document for an example:

https://www.thegeekstuff.com/2013/08/enable-ssh-cisco

HTH

[Julio E. Moisa]

Hi

Did you use the following command to re-generate the key?

crypto key zeroize rsa

it will remove the current key and once it is done you must execute again: crypto key generate rsa ...

[andrewcisco1]

Just a warning to anyone who comes across this article, the command below wipes ALL certificates and keys off the device, not just RSA as it suggests.
crypto key zeroize rsa