topic Re: How to close port 161 corresponding to SNMP V1 ? in Switches, Hubs, and Modems

How to close port 161 corresponding to SNMP V1 ?

TOUCHET — Mon, 20 Dec 2010 14:44:10 GMT

Hello,
I am actually using the switch HP Procurve 2848 and 2910al and I would like to close the 161 port corresponding to snmpv1.
Even if I do a no snmpv3 enable, I am still observing the snmpv1 port open with nmap.
Is it possible to close the port snmpv1 (161) ?

Best regards,

Re: How to close port 161 corresponding to SNMP V1 ?

Mohammed Faiz — Tue, 21 Dec 2010 09:46:57 GMT

Hi,

The best way to do this is to use the "ip authorized-managers" command to lock access to those addresses (either whole subnets or specific IP addresses) you want.

HTH

Re: How to close port 161 corresponding to SNMP V1 ?

TOUCHET — Tue, 21 Dec 2010 13:36:15 GMT

Hello,
The snmpv1 and v2 is still living on the switch. I could only disable snmpv3 and restrict the IP authorized to access to the switch.
However it is not possible to kill or stop the snmpv1 "service" that is still running.

Best regards,

Re: How to close port 161 corresponding to SNMP V1 ?

Mohammed Faiz — Tue, 21 Dec 2010 14:51:10 GMT

Hi,

Yes, it won't stop the SNMP service running on the switch but only those addresses listed in ip auth-managers will be able to query the switch using SNMP.

Re: How to close port 161 corresponding to SNMP V1 ?

TOUCHET — Tue, 21 Dec 2010 15:07:26 GMT

Thanks for you quick response.

Another question :
When I do a telnet to the switch, I get a banner with a lot of information (switch model number, software revision,etc). Is it possible to reduce these information (banner) when we do a telnet (or http:\\) without disabling the web browser and telnet option ?

Best regards,
Anthony TOUCHET

Re: How to close port 161 corresponding to SNMP V1 ?

Mohammed Faiz — Tue, 21 Dec 2010 15:21:03 GMT

No, I don't believe there is a way of removing the text that's displayed after you login.

Re: How to close port 161 corresponding to SNMP V1 ?

TOUCHET — Tue, 21 Dec 2010 15:52:02 GMT

When we disable the web management, it disables the web browser interface through the port 80 http, but does it stop the https also ?
Best regards,

Re: How to close port 161 corresponding to SNMP V1 ?

Mohammed Faiz — Tue, 21 Dec 2010 15:55:27 GMT

If you don't have "web-management ssl" configured and you have set "no web-management" then both port 80 and 443 access to the switch are disabled.

Re: How to close port 161 corresponding to SNMP V1 ?

TOUCHET — Tue, 21 Dec 2010 16:18:46 GMT

Could we use SSL (by enabling SSL) through only one authorized address to secure and restrict the access to the switch ?

Re: How to close port 161 corresponding to SNMP V1 ?

Mohammed Faiz — Tue, 21 Dec 2010 16:20:40 GMT

That's what the "ip authorized-managers" command does.