By default, the Cisco IOS runs some services that are unnecessary
Besides encryption, ACLs, and authorization, there are additional commands we can configure on our perimeter routers to limit access to it. By default, the Cisco IOS runs some services that are unnecessary to its normal operation, and if we don't disable them, they can be easy targets for DoS attacks and break-in attempts.
Plus, if we just use a Cisco router's default settings, it won't check routing paths to stop illegitimate traffic, and ARP traffic will be allowed to pass through its interfaces. We'll now look at how to turn off these unneeded services.
Lab_B(config)#no service tcp-small-servers
Lab_B(config)#no service udp-small-servers
Lab_B(config)#no service finger
Lab_B(config)#no ip boot server
Lab_B(config)#no service config
Lab_B(config)#no ip source-route
Lab_B(config-if)#no ip proxy-arp
Lab_B(config)#no ip forward-protocol udp 69
Lab_B(config)#no ip forward-protocol udp 53
Lab_B(config)#no ip forward-protocol udp 37
Lab_B(config)#no ip forward-protocol udp 137
Lab_B(config)#no ip forward-protocol udp 138
Lab_B(config)#no ip forward-protocol udp 68
Lab_B(config)#no ip forward-protocol udp 49
Guys, I want to know that,shall i disable all the above cited default service in cisco 1811 router or its already disabled...
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Re: By default, the Cisco IOS runs some services that are unnece
With regards to the ?no ip proxy-arp? on Ethernet or FastEthernet interface, what exactly it does? Please advice.
Lab_B(config)#no service config ( we do not have any configuration server in our network from where we can download configuration file)
I have found that we need to configure the Exec-timeout Command is used to drop an idle Exec session after the idle time specified in minutes and second occurs. The exec command enables or disables access to the EXEC process for line.
exec-timeout 5 0
And no tcp-keepalives-in and out generates keepalive packets on idle outgoing network connections (initiated by a user). To disable the keepalives, use the no form of this command
What are the other commands which we need to implement on our perimeter router for enhance the security?
Login to the FXOS chassis manager.
Direct your browser to https://hostname/, and log-in using the user-name and password.
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We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...