- Generate A Rsa Crypto Key Cisco Router Account
- Generate Rsa Crypto Key Cisco
- Cisco Router Crypto Key Generate Rsa
- Crypto Key Generate Rsa
router(config)# hostname R1
R1(config)# ip domain-name ccie.com
–> To define a default domain name that the Cisco IOS software uses to complete unqualified host names
R1(config)# ip domain-name ccie.com
–> To define a default domain name that the Cisco IOS software uses to complete unqualified host names
Generate A Rsa Crypto Key Cisco Router Account
This article shows how to configure and setup SSH for remote management of Cisco IOS Routers.We’ll show you how to check if SSH is supported by your IOS version, how to enable it, generate an RSA key for your router and finally configure SSH as the preferred management protocol under the VTY interfaces. Secure Shell (SSH) provides a secure and reliable mean of. How many bits in the modulus 512: 512% Rsa keys cannot be generated, as system clock is invalid cryptolibkeypairget failed to get RouterD.inter-vlan.com RouterD(config)#crypto key generate rsa general-keys? Exportable Allow the key to be exported label Provide a label modulus Provide number of modulus bits on the command line storage. How to create self-signed certificates An article by Fabio Semperboni Tutorial A digital certificate or identity certificate is an electronic document which uses a digital signature to bind a public key with an identity, information such as the name of a person or an organization, their address, and so forth.
R1(config)# crypto key generate rsa
–> To generate RSA key pairs
–> To generate RSA key pairs
The name for the keys will be: R1.ccie.com
Choose the size of the key modulus in the range of 360 to 2048 for your General purpose keys. Choosing a key modulus
greater than 512 may take a few minutes
Choose the size of the key modulus in the range of 360 to 2048 for your General purpose keys. Choosing a key modulus
greater than 512 may take a few minutes
How many bits in the modulus [512]: 1024
–> modulus : determines the strength of the key , the higher the modulus number the strong the key is
the higher the modulus number the more CPU cycles you are going to have to use encrypt and decrypt
–> modulus : determines the strength of the key , the higher the modulus number the strong the key is
the higher the modulus number the more CPU cycles you are going to have to use encrypt and decrypt
R1(config)# username edaoud privilege 15 secret cisco
–> To establish a username-based authentication system
–> To establish a username-based authentication system
R1(config)# line vty 0 4
–> for telnet per default, there is five lines, 0 to 4
–> for telnet per default, there is five lines, 0 to 4
R1(config-line)# login local
–> To enable password checking at login
–> To enable password checking at login
R1(config-line)# transport input ssh
–> To define protocol SSH to be used to connect to a specific line of the router
–> To define protocol SSH to be used to connect to a specific line of the router
R1(config)# ip ssh version 2
–> Specify protocol version to be supported
–> Specify protocol version to be supported
R1(config)# ip ssh time-out <0-120> ms
–> Specify SSH time-out interval
–> Specify SSH time-out interval
R1(config)# ip ssh authentication-retries <0-5>
–> Specify number of authentication retries
–> Specify number of authentication retries
R1(config)# ip ssh maxstartups
–> Max concurrent session allowed
–> Max concurrent session allowed
R2# ssh -l edaoud 10.1.12.1
–> Specifies the user ID to use when logging in on the remote networking device that is running the SSH server.
–> Specifies the user ID to use when logging in on the remote networking device that is running the SSH server.
router# show ssh
%No SSHv2 server connections running.
%No SSHv1 server connections running.
%No SSHv2 server connections running.
%No SSHv1 server connections running.
router# sh ip ssh
SSH Disabled – version 1.99
%Please create RSA keys to enable SSH (and of atleast 768 bits for SSH v2).
Authentication timeout: 120 secs; Authentication retries: 3
Minimum expected Diffie Hellman key size : 1024 bits
IOS Keys in SECSH format(ssh-rsa, base64 encoded): NONE
SSH Disabled – version 1.99
%Please create RSA keys to enable SSH (and of atleast 768 bits for SSH v2).
Authentication timeout: 120 secs; Authentication retries: 3
Minimum expected Diffie Hellman key size : 1024 bits
IOS Keys in SECSH format(ssh-rsa, base64 encoded): NONE
router# show control-plan host open-ports
router# show tcp
router# show tcp
Below Quote are taken from CCIE Routing and Switching Exam Certification Guide 4th Edition.
Using Secure Shell Protocol
Telnethas long been used to manage network devices; however, Telnet traffic is sent in clear text. Anyone
able to sniff that traffic would see your password and any other information sent during the Telnet
session. Secure Shell (SSH) is a much more secure way to manage your routers and switches. It
is a client/server protocol that encrypts the traffic in and out through the vty ports.
Cisco routers and switches can act as SSH clients by default, but must be configured to be SSH
servers. That is, they can use SSH when connecting to another device, but require configuration
before allowing devices to connect via SSH to them. They also require some method of
authenticating the client. This can be either a local username and password, or authentication with
a AAA server (AAA is detailed in the next section).
There are two versions of SSH. SSH Version 2 is an IETF standard that is more secure than version
1. Version 1 is more vulnerable to man-in-the-middle attacks, for instance. Cisco devices support
both types of connections, but you can specify which version to use.
Telnet is enabled by default, but configuring even a basic SSH server requires several steps:
1. Ensure that your IOS supports SSH. You need a K9 image for this.
2. Configure a host name, unless this was done previously.
3. Configure a domain name, unless this was done previously.
4. Configure a client authentication method.
5. Tell the router or switch to generate the Rivest, Shamir, and Adelman (RSA) keys that will be
used to encrypt the session.
6. Specify the SSH version, if you want to use version 2.
7. Disable Telnet on the VTY lines.
8. Enable SSH on the VTY lines.
Example 18-4 shows a router being configured to act as an SSH server.
able to sniff that traffic would see your password and any other information sent during the Telnet
session. Secure Shell (SSH) is a much more secure way to manage your routers and switches. It
is a client/server protocol that encrypts the traffic in and out through the vty ports.
Cisco routers and switches can act as SSH clients by default, but must be configured to be SSH
servers. That is, they can use SSH when connecting to another device, but require configuration
before allowing devices to connect via SSH to them. They also require some method of
authenticating the client. This can be either a local username and password, or authentication with
a AAA server (AAA is detailed in the next section).
There are two versions of SSH. SSH Version 2 is an IETF standard that is more secure than version
1. Version 1 is more vulnerable to man-in-the-middle attacks, for instance. Cisco devices support
both types of connections, but you can specify which version to use.
Telnet is enabled by default, but configuring even a basic SSH server requires several steps:
1. Ensure that your IOS supports SSH. You need a K9 image for this.
2. Configure a host name, unless this was done previously.
3. Configure a domain name, unless this was done previously.
4. Configure a client authentication method.
5. Tell the router or switch to generate the Rivest, Shamir, and Adelman (RSA) keys that will be
used to encrypt the session.
6. Specify the SSH version, if you want to use version 2.
7. Disable Telnet on the VTY lines.
8. Enable SSH on the VTY lines.
Example 18-4 shows a router being configured to act as an SSH server.
Example 18-4 SSH Configuration
router(config)# hostname R3
R3(config)# ip domain-name CCIE2B
R3(config)# username cisco password Cisco
R3(config)# crypto key generate rsa
The name for the keys will be: R3.CCIE2B
Choose the size of the key modulus in the range of 360 to 2048 for your
General Purpose Keys. Choosing a key modulus greater than 512 may take
a few minutes.
How many bits in the modulus [512]: 1024
% Generating 1024 bit RSA keys …[OK]
R3(config)#
*May 22 02:06:51.923: %SSH-5-ENABLED: SSH 1.99 has been enabled
R3(config)# ip ssh version 2
!
R3(config)# line vty 0 4
R3(config-line)# transport input none
R3(config-line)# transport input ssh
R3(config-line)#^Z
!
R3# show ip ssh
SSH Enabled- version 2.0
Authentication timeout: 120 secs; Authentication retries: 3
router(config)# hostname R3
R3(config)# ip domain-name CCIE2B
R3(config)# username cisco password Cisco
R3(config)# crypto key generate rsa
The name for the keys will be: R3.CCIE2B
Choose the size of the key modulus in the range of 360 to 2048 for your
General Purpose Keys. Choosing a key modulus greater than 512 may take
a few minutes.
How many bits in the modulus [512]: 1024
% Generating 1024 bit RSA keys …[OK]
R3(config)#
*May 22 02:06:51.923: %SSH-5-ENABLED: SSH 1.99 has been enabled
R3(config)# ip ssh version 2
!
R3(config)# line vty 0 4
R3(config-line)# transport input none
R3(config-line)# transport input ssh
R3(config-line)#^Z
!
R3# show ip ssh
SSH Enabled- version 2.0
Authentication timeout: 120 secs; Authentication retries: 3
- October 2, 2015
- Posted by: Syed Shujaat
- Category: Cisco, Networking Solutions
Use this command to generate RSA key pairs for your Cisco device (such as a router). keys are generated in pairs–one public RSA key and one private RSA key.
If your router already has RSA keys when you issue this command, you will be warned and prompted to replace the existing keys with new keys.
NOTE: Before issuing this command, ensure that your router has a hostname and IP domain name configured (with the hostname and ipdomain-name commands).
You will be unable to complete the cryptokeygeneratersacommand without a hostname and IP domain name. (This situation is not true when you generate only a named key pair.)
Here are the steps to Enable SSH and Crypto Key setup : 2 config must requried for SSH
1 Setup Local VTY line User ID and password
router (Config) # Line VTY 0 15
router (Config-line)# login local
router (Config-line)# Exit
!!! create local login ID/Pass
router (Config)# username [loginid] password [cisco]
router (Config)# username loginid1 password cisco1
2. router (Config)# ip domain-name example.com
router (Config)# crypto key generate rsa
how many bits in the modulus [512] :1024
router (Config)# ip ssh version2
router (Config)# CTRL Z
Note | Secure Shell (SSH) may generate an additional RSA key pair if you generate a key pair on a router having no RSA keys. The additional key pair is used only by SSH and will have a name such as {router_FQDN }.server. For example, if a router name is “router1.cisco.com,” the key name is “router1.cisco.com.server.” |
This command is not saved in the router configuration; however, the RSA keys generated by this command are saved in the private configuration in NVRAM (which is never displayed to the user or backed up to another device) the next time the configuration is written to NVRAM.
Modulus Length
When you generate RSA keys, you will be prompted to enter a modulus length. The longer the modulus, the stronger the security. However, a longer modules take longer to generate (see the table below for sample times) and takes longer to use.
The size of Key Modulus range from 360 to 2048. Choosing modulus greater than 512 will take longer time.
Generate Rsa Crypto Key Cisco
Router | 360 bits | 512 bits | 1024 bits | 2048 bits (maximum) |
---|---|---|---|---|
Cisco 2500 | 11 seconds | 20 seconds | 4 minutes, 38 seconds | More than 1 hour |
Cisco 4700 | Less than 1 second | 1 second | 4 seconds | 50 seconds |
Cisco IOS software does not support a modulus greater than 4096 bits. A length of less than 512 bits is normally not recommended. In certain situations, the shorter modulus may not function properly with IKE, so we recommend using a minimum modulus of 2048 bits.
Syntax Description : Optional Strings to embed with SSH Crypto key
Cisco Router Crypto Key Generate Rsa
general-keys | (Optional) Specifies that a general-purpose key pair will be generated, which is the default. | ||
usage-keys | (Optional) Specifies that two RSA special-usage key pairs, one encryption pair and one signature pair, will be generated. | ||
signature | (Optional) Specifies that the RSA public key generated will be a signature special usage key. | ||
encryption | (Optional) Specifies that the RSA public key generated will be an encryption special usage key. | ||
labelkey-label | (Optional) Specifies the name that is used for an RSA key pair when they are being exported.If a key label is not specified, the fully qualified domain name (FQDN) of the router is used. | ||
exportable | (Optional) Specifies that the RSA key pair can be exported to another Cisco device, such as a router. | ||
modulusmodulus-size | (Optional) Specifies the IP size of the key modulus.By default, the modulus of a certification authority (CA) key is 1024 bits. The recommended modulus for a CA key is 2048 bits. The range of a CA key modulus is from 350 to 4096 bits.
| ||
storagedevicename: | (Optional) Specifies the key storage location. The name of the storage device is followed by a colon (:). | ||
redundancy | (Optional) Specifies that the key should be synchronized to the standby CA. | ||
ondevicename: | (Optional) Specifies that the RSA key pair will be created on the specified device, including a Universal Serial Bus (USB) token, local disk, or NVRAM. The name of the device is followed by a colon (:).Keys created on a USB token must be 2048 bits or less. |
Command | Description |
---|---|
copy | Copies any file from a source to a destination, use the copy command in privileged EXEC mode. |
cryptokeystorage | Sets the default storage location for RSA key pairs. |
debugcryptoengine | Displays debug messages about crypto engines. |
hostname | Specifies or modifies the hostname for the network server. |
ipdomain-name | Defines a default domain name to complete unqualified hostnames (names without a dotted-decimal domain name). |
showcryptokeymypubkeyrsa | Displays the RSA public keys of your router. |
show crypto pki certificates | Displays information about your PKI certificate, certification authority, and any registration authority certificates. |