Security Configuration Guide, Cisco IOS XE Fuji 16.8.x (Catalyst 9500 Switches)

Prerequisites for SSH Support over IPv6

An IPsec (Data Encryption Standard [DES] or 3DES) encryption software image is loaded on your device. IPv6 transport for the SSH server and SSH client requires an IPsec encryption software image.
A hostname and host domain are configured for your device.
A Rivest, Shamir, and Adelman (RSA) key pair, which automatically enables SSH, is generated for your device.
A user authentication mechanism for local or remote access is configured on your device.
To authenticate SSH clients, configure TACACS+ or RADIUS over an IPv4 transport and then connect to an SSH server over an IPv6 transport.

The basic restrictions for SSH over an IPv4 transport apply to SSH over an IPv6 transport. The use of locally stored usernames and passwords is the only user authentication mechanism supported by SSH over an IPv6 transport. TACACS+ and RADIUS user authentication mechanisms are not supported over an IPv6 transport.

SSH over an IPv6 Transport

Secure shell (SSH) SSH in IPv6 functions the same and offers the same benefits as SSH in IPv4. The SSH server feature enables an SSH client to make a secure, encrypted connection to a Cisco device, and the SSH client feature enables a Cisco device to make a secure, encrypted connection to another Cisco device or to any other device running an SSH server. IPv6 enhancements to SSH consist of support for IPv6 addresses that enable a Cisco device to accept and establish secure, encrypted connections with remote IPv6 nodes over an IPv6 transport.

Enabling SSH on an IPv6 Device

This task is optional. If you do not configure SSH parameters, then the default values will be used.

Procedure

	Command or Action	Purpose
Step 1	enable Example: `Device> enable`	Enables privileged EXEC mode. Enter your password if prompted.
Step 2	configure terminal Example: `Device# configure terminal`	Enters global configuration mode.
Step 3	ip ssh [timeout `seconds` \| authentication-retries `integer` ] Example: `Device(config)# IP ssh timeout 100 authentication-retries 2`	Configures SSH control variables on your device.
Step 4	exit Example: `Device(config)# exit`	Exits global configuration mode, and returns to privileged EXEC mode.
Step 5	ssh [ -v { 1 \| 2 } \| c { 3des \| aes128-cbc \| aes192-cbc \| aes256-cbc } \| -l `userid` \| -l `userid:vrfname number ip-address` `ip-address` \| -l `userid:rotary number` `ip-address` \| -m { hmac-md5 \| hmac-md5-96 \| hmac-sha1 \| hmac-sha1-96 } \| -o numberofpasswordprompts `n` \| -p `port-num`] { ip-addr \| hostname} [ command \| -vrf] Example: `Device# ssh -l userid1 2001:db8:2222:1044::72`	Starts an encrypted session with a remote networking device.

Example: Enabling SSH on an IPv6 Device

Device# configure terminal
Device(config)# ip ssh
Device(config)# exit
Device# ssh -l userid1 2001:db8:2222:1044::72

Additional References for SSH Support over IPv6

Related Topic	Document Title
SSH Version 1 and Version 2 Support	Configuring Secure Shell and Secure Shell Version 2 Support chapters of the Security Configuration Guide.

Standards and RFCs


Standard/RFC	Title
RFCs for IPv6	IPv6 RFCs

Technical Assistance


Description	Link
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Feature History for SSH Support over IPv6

This table provides release and related information for features explained in this module.

These features are available on all releases subsequent to the one they were introduced in, unless noted otherwise.


Release	Feature	Feature Information
Cisco IOS XE Everest 16.5.1a	SSH Support over IPv6	SSH provides support for IPv6 addresses that enable a Cisco device to accept and establish secure, encrypted connections with remote IPv6 nodes over an IPv6 transport. Support for this feature was introduced on all the models of the Cisco Catalyst 9500 Series Switches.
Cisco IOS XE Fuji 16.8.1a	SSH Support over IPv6	Support for this feature was introduced on the C9500-32C, C9500-32QC, C9500-48Y4C, and C9500-24Y4C models of the Cisco Catalyst 9500 Series Switches.

Use Cisco Feature Navigator to find information about platform and software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn.

Book Title

Chapter Title

Results

Chapter: SSH Support Over IPv6

SSH Support Over IPv6

Prerequisites for SSH Support over IPv6

SSH over an IPv6 Transport

Enabling SSH on an IPv6 Device

Procedure

Example:

Example:

Example:

Example:

Example:

Example: Enabling SSH on an IPv6 Device

Additional References for SSH Support over IPv6

Related Documents

Standards and RFCs

Technical Assistance

Feature History for SSH Support over IPv6

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