Configuring SSH Access | Cisco Systems OL-5650-02 manual

Chapter 2 Configuring the Secure Shell Daemon Protocol

Configuring SSH Access

Configuring SSH Access

SSH access to the CSS is enabled by default through the no restrict ssh command. You can verify the SSH access selection in the running-config file.

To enhance security when using SSHD, disable Telnet access (Telnet access is enabled by default). Use the telnet-access disable command as described in Chapter 1, Controlling CSS Access.

To enable SSH access to the CSS, enter:

(config)# no restrict ssh

To disable SSH access, enter:

(config)# restrict ssh

Configuring SSHD in the CSS

The CSS provides the following commands for configuring SSHD:

•sshd keepalive - Enables TCP keepalive messages

•sshd port - Specifies the SSHD port

•sshd server-keybits- Sets the number of bits in the ephemeral protocol server key (SSH v1 only)

•sshd version - Configures the version of SSH protocol that the CSS supports.

Ensure you enable SSHD access to the CSS for SSHD to accept connections from SSH clients. By default, SSH access is enabled through the no restrict ssh global command.

Configuring SSHD Keepalive

The CSS supports sending TCP keepalive messages to the client as a means for the server to determine whether the SSHD connection to the client is functioning (for example, if the network has gone down or the client has become unresponsive). If you disable sending SSHD keepalives to a client, sessions may hang indefinitely on the server, which consumes system resources.

		Cisco Content Services Switch Security Configuration Guide
		Cisco Content Services Switch Security Configuration Guide
	OL-5650-02			2-3
	OL-5650-02			2-3

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Cisco Systems OL-5650-02 manual Configuring SSH Access, Configuring Sshd in the CSS, Configuring Sshd Keepalive

Contents

Cisco Content Services Switch Security Configuration Guide Cisco Content Services Switch Security Configuration Guide Iii N T E N T S ACL Overview Configuring the CSS as a Client of a Radius Server Configuring Firewall Load Balancing Vii Example of Fwlb Viii B L E S OL-5650-02 Preface Xii How to Use This GuideAudience Xiii Related Documentation Xiv Rmon Document Title Description Xvi Symbols and Conventions Xvii Obtaining DocumentationCisco.com Documentation DVD Documentation FeedbackOrdering Documentation Xviii Xix Reporting Security Problems in Cisco ProductsCisco Product Security Overview Cisco Technical Support Website Obtaining Technical Assistance Xxi Submitting a Service Request Xxii Definitions of Service Request Severity Xxiii Xxiv Controlling CSS Access Config# username-offdm bobo password secret Changing the Administrative Username and Password Config# username picard password captain superuser Creating Usernames and Passwords Controlling CSS Access Creating Usernames and Passwords Config# username picard password flute superuser Config# username picard password captain superuser NwbnnnrConfig# no username picard Controlling Remote User Access to the CSS Configuring Virtual Authentication #config virtual authentication secondary local Configuring Console Authentication#config virtual authentication primary tacacs #config no console authentication #config console authentication primary tacacs#config console authentication secondary local Enabling Administrative Access to the CSS Controlling Administrative Access to the CSS Config# no restrict web-mgmt Disabling Administrative Access to the CSS Config# restrict telnet Controlling CSS Network Traffic Through Access Control Lists ACL Overview ACL ACL Configuration Quick Start Config-acl7#apply circuit-VLAN1 Config-acl7#clause 10 deny any any destination range 20Config-acl7#clause 15 permit any any destination any Creating an ACL Deleting an ACL Config# acl disableConfig-acl7#remove circuit-VLAN1 Configuring Clauses Cisco Content Services Switch Security Configuration Guide Variables Options Parameters Destination content ownername/ rulename for an Variables OptionsParameters Show group ? Variables Options Parameters Prefer Adding a Clause When ACLs are Globally Enabled Deleting a Clause Config-acl7remove circuit-VLAN1Config-acl7apply circuit-VLAN1 Applying an ACL to a Circuit or DNS Queries Removing an ACL from Circuits or DNS Queries Enabling ACLs on the CSS Showing ACLs Disabling ACLs on the CSS Field Description Logging ACL Activity Setting the Show ACL Counters to Zero Config-acl7#clause 1 log disable Config-acl7#clause 1 log enable ACL Example Config# no logging subsystem acl Configuring Network Qualifier Lists for ACLs Adding Networks to an NQL Creating an NQLDescribing an NQL Config-nqlbypassnql#no ip address 192.168.0.0/16 Config# logging subsystem nql level debug-7 Adding an NQL to an ACL Clause Showing NQL Configurations Configuring the Secure Shell Daemon Protocol # license Enabling SSH Configuring Sshd in the CSS Configuring SSH AccessConfiguring Sshd Keepalive Config# no restrict ssh Configuring Sshd Server-Keybits Configuring Sshd Port Config# sshd server-keybits Configuring Sshd VersionConfig# no sshd server-keybits Config# sshd version Showing Sshd Configurations Configuring Telnet Access When Using SshdConfig# no restrict telnet # show sshd config # show sshd sessions # show sshd version Ptyfd Radius Server Configuring the CSS as a Client of a Radius Server Config# radius-server secondary 172.27.56.79 secret Hello Radius Configuration Quick StartConfig# radius-server primary 172.27.56.76 secret Hello #config virtual authentication primary radius Configuring a Radius Server for Use with the CSS Configuring Authorization Settings Configuring Authentication Settings Specifying a Primary Radius Server Specifying a Secondary Radius Server Config# no radius-server primaryConfig# no radius-server secondary Configuring the Radius Server Retransmits Configuring the Radius Server TimeoutsConfig# radius-server timeout Config# no radius-server timeout Config# no radius-server retransmit Configuring the Radius Server Dead-TimeConfig# radius-server dead-time Config# no radius-server dead-time DOWN, Unknown Config# show radius statistics secondary 3describes the fields in the show radius statistics output OL-5650-02 TACACS+ Server TACACS+ Configuration Quick Start Config# show tacacs-server Configuring Authorization Settings Configuring Global TACACS+ Attributes #config no tacacs-server timeout Setting the Global CSS TACACS+ Timeout Period#config tacacs-server timeout #config tacacs-server key market Setting the Global TACACS+ Keepalive Frequency#config tacacs-server key acskefterefesdtx #config no tacacs-server key Defining a TACACS+ Server Config# no tacacs-server frequency OL-5650-02 #config no tacacs-server 192.168.11.1 Setting TACACS+ Authorization #config tacacs-server authorize non-config #config tacacs-server authorize config#config no tacacs-server authorize config #config no tacacs-server authorize non-config Setting TACACS+ Accounting Showing TACACS+ Server Configuration Information Field Description OL-5650-02 Configuring Firewall Load Balancing Overview of Fwlb Firewall Synchronization Configuring Fwlb Config# no ip firewall Configuring a Keepalive Timeout for a FirewallConfig# ip firewall 1 192.168.27.1 192.168.28.1 Config# no ip firewall timeout Configuring an IP Static Route for a FirewallConfig# ip firewall timeout Config# ip route 192.168.2.0/24 firewall 1 Configuring Ospf to Advertise Firewall RoutesConfig# no ip route 192.168.2.0/24 firewall Config# ospf redistribute firewall metric 3 type1 Example of Fwlb Static Route Configuration Configuring RIP to Advertise Firewall RoutesConfig# no ospf redistribute firewall Config# rip redistribute firewall Config# ip route 192.168.2.0/24 firewall Config# ip firewall 1 192.168.28.1 192.168.27.1Config# ip firewall 2 192.168.28.2 192.168.27.2 Config# ip route 0.0.0.0/0 firewall Example of Fwlb Configuring Fwlb with VIP and Virtual Interface Redundancy Fwlb with VIP/Interface Redundancy Configuration Cisco Content Services Switch Security Configuration Guide CSS-OUT-L Configuration Example of Firewall and Route Configurations CSS-IN-L Configuration Displaying Firewall Flow Summaries Config# show flows 192.165.22.1Config# show flows Displaying Firewall IP Routes Config# show ip routes firewall Displaying Firewall IP Information Config# show ip firewall OL-5650-02 IN-1 D E IN-2 IN-3 FTP IN-4 Radius IN-5 XML IN-6