1

I have configured a couple of VLANs on a Cisco Catalyst switch with IOS, i will put all the ports that clients is connected to, into these VLANs. I want to configure the native VLAN [vlan 1] as management VLAN so i can use a telnet client to connect to the switch.

How can i block all but one specific IP-address to telnet into the switch? As i understand vlan 1 has many task regarding different protocols and i do not want to break that but only allow one specific IP-address to connect to the switch with a telnet client [actually the gateway ip address of the switch].

  • IOS or CatOS? Version? – pehrs Apr 17 '10 at 9:29
  • I forgot to mention that i the post. It is IOS – cha789 Apr 17 '10 at 9:31
  • It's bad form to use VLAN 1 for anything but a parking vlan for unused ports. – Zypher Apr 17 '10 at 18:01
3

You can apply an ACL just to management access. For instance:

! replace x.x.x.x with the IP to permit
access-list 1 permit host x.x.x.x

! some switches range from 0 to 15 instead of 0 to 4, adjust as necessary
line vty 0 4
 access-class 1 in

This applies standard access list 1 to just inbound access on virtual terminals (which includes telnet and ssh access), irrespective of VLAN. You can use a more sophisticated access-list if needed. Chopper3 provided a good link for that.

2

I'd suggest you use an ACL - they can be quite complex to setup but HERE is Cisco's guide on how to.

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