Re: [fw-wiz] Cisco acls

From: Kevin (kkadow_at_gmail.com)
Date: 03/16/05

  • Next message: Mark Teicher: "Re: [fw-wiz] Cisco acls"
    To: firewall-wizards@honor.icsalabs.com
    Date: Wed, 16 Mar 2005 00:41:47 -0600
    
    

    On Tue, 08 Mar 2005 07:06:23 -0500, Mark Teicher wrote:
    > Has anyone seen or heard of a Cisco ACL lint checker to validate
    > whether a certain acl is being utilized or at all.

    By 'lint' are you suggesting a tool to check whether a line in an ACL
    is redundant, can never be matched because it is "overshadowed" by a
    rule higher up in a "first-match" policy? That *would* be neat.

    IIRC, OpenBSD has something close in the latest 'pf' rule optimization
    efforts, however pf rules are "last match" unlike Cisco's "first
    match" model.

    > What about old acls that have been around for a while,
    > and no one understands why they were inserted in the first place.

    Cisco has counters for how many times an ACL line has matched a
    packet, since the last time the counters were cleared, the ACL
    changed, or the device rebooted.
    Extended ACLs support comments. I include a date, a name, and a
    couple of words as to why the following rule exists. Audit loves
    this, CCIE's hate it.

    Kevin Kadow
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  • Next message: Mark Teicher: "Re: [fw-wiz] Cisco acls"

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