04-02-2018 12:25 PM - edited 02-21-2020 07:35 AM
Hi
I am just reviewing one of our L3 cisco router and I am seeing there are 4 different VLAN interfaces configured with IP addresses (wireless , Data , Video , Management ) when I do ssh to this switch from my desktop I am able to use any of these IP addresses on the switch and ssh works fine . MY concern is if this is a security issue or is there any other way we can only ssh to certain IP address on the switch for security concern ?
Thanks
Solved! Go to Solution.
04-02-2018 01:30 PM
You can make an extended ACL pointing to the device IP like this:
ip access-list extended NoSSH deny tcp host <IP> any eq 22 permit ip any any
and apply it to each of the SVI, for example:
ip access-list extended NoSSH deny tcp host 10.2.0.1 any eq 22 permit ip any any interface vlan 10 ip access-group NoSSH in
04-02-2018 12:59 PM
Hi
By default, your device answer ssh connections from all the interfaces VLAN, you can restrict that by using ACL that prohibits incoming SSH in the interfaces you want to
04-02-2018 01:22 PM
well only ACL for ssh I know is basically specifying individual hosts or networks that can access to my device and apply in under line vty connection . for example below is my current ssh configuration
access-list 100 permit ip 10.1.x.0 0.0.255.255 any
access-list 100 permit ip 10.x.x.0 0.0.0.255 any
line vty 0 4
access-class 100 in
exec-timeout 9 0
transport input ssh
so as far as I know this will give access to those networks below to my network device . but I want to to use only one of the SVI interfaces for ssh , if there is any ssh attempt o other SVIs it should be denied .
currently
I have fallowing SVIs are availables below
vlan 10 10.2.0.1
vlan 20 10.2.30.1
vlan 30 10.2.40.1
04-02-2018 01:30 PM
You can make an extended ACL pointing to the device IP like this:
ip access-list extended NoSSH deny tcp host <IP> any eq 22 permit ip any any
and apply it to each of the SVI, for example:
ip access-list extended NoSSH deny tcp host 10.2.0.1 any eq 22 permit ip any any interface vlan 10 ip access-group NoSSH in
04-02-2018 01:39 PM
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