Comware

 View Only
Expand all | Collapse all

can we disable ICMP netmask reply in HP 5500 Switch?

This thread has been viewed 0 times
  • 1.  can we disable ICMP netmask reply in HP 5500 Switch?

    Posted Jul 01, 2015 11:20 PM

    customer has both cisco/hp devices in their network and is able to enable/disable 'ip mask-reply' on cisco units, but wondering what's the substitute in 3com/H3C (hp 5500IE switch)..

    I could see that the function 'netmask request/reply' works on h3c switch, however, not sure how to configure these functions on the switch?
    what's the default state of 'netmask reply'... is it disabled by default?

    ******************************
    ******************************
    dis ip interface Vlan-interface 1

    Vlan-interface1 current state :UP
    Line protocol current state :UP
    Internet Address is 16.48.50.125/24, acquired via DHCP
    Broadcast address : 16.48.50.255
    The Maximum Transmit Unit : 1500 bytes
    input packets : 1005412, bytes : 126354989, multicasts : 0
    output packets : 493581, bytes : 33711876, multicasts : 0
    ARP packet input number: 104031313
    Request packet: 103992340
    Reply packet: 38973
    Unknown packet: 0
    TTL invalid packet number: 0
    ICMP packet input number: 269054
    Echo reply: 5
    Unreachable: 73
    Source quench: 0
    Routing redirect: 0
    Echo request: 268740
    Router advert: 0
    Router solicit: 0
    Time exceed: 0
    IP header bad: 0
    Timestamp request: 24
    Timestamp reply: 0
    Information request: 0
    Information reply: 0
    Netmask request: 24
    Netmask reply: 0
    Unknown type: 188



  • 2.  RE: can we disable ICMP netmask reply in HP 5500 Switch?

    Posted Jul 10, 2015 03:46 PM

    I failed to locate a specific command to allow/disallow ICMP netmask replies.

     

    However  you can setup ACL's to filter either type 17 code 0 (request, which is the preferred since you normally want to block the original request and not waste any system resources on a reply which will be dropped anyway) or type 18 code 0 (reply itself).

     

    Like so:

     

    rule 1234 deny icmp icmp-type 17 0 destination 1.2.3.4 0

     

    Where 1.2.3.4 is the ip of the router you wish to protect, or you could just drop any address mask requests like so:

     

    rule 1234 deny icmp icmp-type 17 0

     

    For more info:

     

    https://en.wikipedia.org/wiki/Internet_Control_Message_Protocol