10-26-2021 01:42 AM
Hello all,
I have cisco 2911 router with public IP enabled.
I am able to connect my router through putty SSH using my private IP, and it works fine.
But when I try to connect the router using public IP from outside the network, it says "Network error: Connection refused".
Here is some information about router configuration for your reference:
#show version
Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.4(3)M1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2014 by Cisco Systems, Inc.
Compiled Sat 25-Oct-14 03:34 by prod_rel_team
ROM: System Bootstrap, Version 15.0(1r)M6, RELEASE SOFTWARE (fc1)
DeaJon1 uptime is 5 days, 23 hours, 14 minutes
System returned to ROM by reload at 09:34:10 UTC Wed Oct 20 2021
System image file is "flash0:c2900-universalk9-mz.SPA.154-3.M1.bin"
Last reload type: Normal Reload
Last reload reason: Reload Command
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
compliance 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.
Cisco CISCO2911/K9 (revision 1.0) with 483328K/40960K bytes of memory.
Processor board ID FTX1427AHQ4
3 Gigabit Ethernet interfaces
1 terminal line
8 Voice FXO interfaces
DRAM configuration is 64 bits wide with parity enabled.
255K bytes of non-volatile configuration memory.
254464K bytes of ATA System CompactFlash 0 (Read/Write)
License Info:
License UDI:
-------------------------------------------------
Device# PID SN
-------------------------------------------------
*1 CISCO2911/K9 FTX1427AHQ4
Technology Package License Information for Module:'c2900'
------------------------------------------------------------------------
Technology Technology-package Technology-package
Current Type Next reboot
------------------------------------------------------------------------
ipbase ipbasek9 Permanent ipbasek9
security None None None
uc uck9 Permanent uck9
data None None None
NtwkEss None None None
CollabPro None None None
Configuration register is 0x2101
#show ip ssh
SSH Enabled - version 2.0
Authentication methods: publickey, keyboard-interactive, password
Authentication timeout: 120 secs; Authentication retries: 3
Minimum expected Diffie Hellman key size : 1024 bits
IOS Keys in SECSH format(ssh-rsa, base64 encoded):
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQCMueDzv0jZEIG/sbuDnTka5Td3cbnMo8XyPFkfR0ND
sD+RB+czPka7Xayj/9UvjficXJ6nabvBmpXvysZDrKiC4VEncBh6iG10QzZqnANhHLyMv3hjONhJW94W
5qEeYvRhLJG1689mTmrwX3aBSqF4vSH1auzRKW5+maKAaZmhcw==
#show run | s line
line con 0
exec-timeout 0 0
---------------
line aux 0
---------------
line 2
no activation-character
no exec
transport preferred none
transport output pad telnet rlogin lapb-ta mop udptn v120 ssh
stopbits 1
---------------
line vty 0 4
login local
transport input all
# show run (ip nat details)
ip nat pool NAT_POOL X.X.X.X X.X.X.X netmask X.X.X.X
ip nat inside source list 10 pool NAT_POOL overload
ip route X.X.X.X X.X.X.x X.X.X.X
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 dhcp
Please help and thanks in advance.
!
!
Solved! Go to Solution.
11-11-2021 10:57 PM
Hello All,
An IOS update has fixed this issue.
The previous version was "15.4(3)M1" and I have updated it to "15.7(3)M8".
Now I am able to ssh the router using its public IP address.
Thanks.
10-26-2021 01:58 AM
Hi there,
Are there any ACLs configured on Gi0/0 ?
cheers,
Seb.
10-26-2021 02:07 AM
10-26-2021 02:12 AM
10-26-2021 02:25 AM
Hi Seb,
More information here:
interface GigabitEthernet0/0
ip address dhcp
ip nat outside
ip virtual-reassembly in
duplex auto
speed auto
!
interface GigabitEthernet0/1
ip address X.X.X.X 255.255.255.0
ip nat inside
ip virtual-reassembly in
duplex auto
speed auto
h323-gateway voip interface
h323-gateway voip bind srcaddr X.X.X.X
!
!
ip nat pool NAT_POOL X.X.X.X X.X.X.X netmask 255.255.255.0
ip nat inside source list 10 pool NAT_POOL overload
ip route X.X.X.X 255.255.255.0 X.X.X.X
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 dhcp
!
!
!
access-list 10 permit X.X.X.X 0.0.0.255
!
10-28-2021 10:29 PM
Hi Seb,
I have not solved this problem yet, any advice?
10-28-2021 11:46 PM
Hello,
your router supports SSH version 2 only:
--> SSH Enabled - version 2.0 (version 1.99 would mean it is backwards compatible with version 1).
Make sure you use the very latest version of Putty (link below):
https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html
You could also try to zeroize and regenerate the crypto key, that often helps:
crypto key zeroize
crypto key generate
10-29-2021 12:31 AM
Hi Mr. Georg,
Thanks for attending my question.
1. I am using the latest version of putty, I even uninstalled my putty and reinstalled from the given link.
2. Like you suggested, I have regenerated the crypto key
But still the problem exist, I am not able to access my router using public IP.
any other options please!!
thanks again
11-11-2021 10:57 PM
Hello All,
An IOS update has fixed this issue.
The previous version was "15.4(3)M1" and I have updated it to "15.7(3)M8".
Now I am able to ssh the router using its public IP address.
Thanks.
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