Comware

 View Only
  • 1.  ARP-protection/DHCP-snooping behaviour questions/logging

    Posted Jul 23, 2010 03:42 AM
    Hi all,

    I ‘m about to implement some LAN protection measures, like dhcp-snooing and arp-protection.

    I have some questions about the behaviour and log-messages of both.

    Switches:
    - 5406zl with uplink to 3500yl and downlink to 5406zl
    o Uplink and downlink are trusted for arp
    o Uplink is trusted for DHCP-snooping
    - 5406zl with uplink to 5406zl
    o Uplink is trusted for arp
    o Uplink is trusted for DHCP-snooping

    ARP-protection

    If a port is “arp-protected”

    1. A pc/server with a fixed IP-address gets its connection refused. Ping results in:

    I 07/22/10 09:22:45 00912 arp-protect: Ceasing bad binding ARP logs for 1m
    I 07/22/10 09:22:45 00911 arp-protect: Deny ARP Reply ‘mac’, ‘ip’ port E11, vlan 194
    I 07/22/10 09:22:45 00911 arp-protect: Deny ARP Reply ‘mac’, ‘ip’ port E11, vlan 194

    2. A pc with a ‘DHCP-address works fine

    DHCP-snooping

    If authorized DHCP-servers are configured.

    1. If a non authorized DHCP-server is connected on a local port ( trusted arp-protect port )

    The next log appears:

    I 07/23/10 08:32:10 00912 arp-protect: Ceasing bad binding ARP logs for 1m
    I 07/23/10 08:32:10 00911 arp-protect: Deny ARP Req ‘mac’,0.0.0.0 port C20, vlan 194
    I 07/23/10 08:32:09 00911 arp-protect: Deny ARP Req ‘mac’,0.0.0.0 port C20, vlan 194

    2. If a non authorized DHCP-server is connected to an uplink switch

    W 07/23/10 09:32:22 00855 dhcp-snoop: backplane: Ceasing unauthorized server log
    s for 5m
    W 07/23/10 09:32:22 00854 dhcp-snoop: backplane: Unauthorized server ‘ip’
    2 detected on port E1

    3. In both cases no log message appears on the downlink switch

    Is this as it should work/log?

    Thanx Jaap


  • 2.  RE: ARP-protection/DHCP-snooping behaviour questions/logging

    Posted Jul 25, 2010 06:41 AM
    Hi Jaap

    Your test setup seem to work pretty much as dfesigned :)

    And logs seem to be good.



  • 3.  RE: ARP-protection/DHCP-snooping behaviour questions/logging

    Posted Jul 30, 2010 07:05 AM
    Tore Valberg Jul 25, 2010 11:40:34 GMT
    Hi Jaap

    Your test setup seem to work pretty much as dfesigned :)

    And logs seem to be good.