forgot the link to the post:

http://blog.ipexpert.com/2010/01/18/cisco-ios-zone-based-firewalls/


Regards,

Brandon Carroll - CCIE #23837
Senior Technical Instructor - IPexpert
Mailto: [email protected]
Telephone: +1.810.326.1444
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On Wed, Feb 3, 2010 at 1:15 PM, Brandon Carroll <[email protected]>wrote:

> Hi Jimmy,
>
> ZBF is always a sticky topic.
>
> Here is my run down:
>
> the ICMP is going to be Stateful so you know it needs to be inspected.  Try
> the following:
>
> ip access-list extended acl-INSIDE-TO-OUTSIDE-no-inspect
>  permit icmp any any eq echo
>
> class-map type inspect class-INSIDE-TO-OUTSIDE-no-inspect
>  match access-group acl-INSIDE-TO-OUTSIDE-no-inspect
>
> policy-map type inspect policy-INSIDE-TO-OUTSIDE
>  class type inspect class-INSIDE-TO-OUTSIDE
>   inspect
>
> ! Next the ICMP- it actually does need to be inspected to allow for the
> reply.
>
> class type inspect class-INSIDE-TO-OUTSIDE-no-inspect
>   inspect
>  class class-default
>   drop
>
>
> You don't do any interfaces ACLs, rather they are handled my the
> class-maps, in other words you nest them in the policy-map.
>
> Here is a basic post I did on the ZBF.  There is another one coming but I'm
> a bit behind.  Hopefully this gives you a push in the right direction.
>
> Also- take a look at the DSG for Lab 2a.  Task 2.11 has ICMP allowed in the
> ZBF configuration.  Perhaps that will help a bit.
>
> Regards,
>
> Brandon Carroll - CCIE #23837
> Senior Technical Instructor - IPexpert
> Mailto: [email protected]
> Telephone: +1.810.326.1444
> Live Assistance, Please visit: www.ipexpert.com/chat
> eFax: +1.810.454.0130
>
> IPexpert is a premier provider of Classroom and Self-Study Cisco CCNA (R&S,
> Voice & Security), CCNP, CCVP, CCSP and CCIE (R&S, Voice, Security & Service
> Provider) Certification Training with locations throughout the United
> States, Europe and Australia. Be sure to check out our online communities at
> www.ipexpert.com/communities and our public website at www.ipexpert.com.
>
>
>
> On Wed, Feb 3, 2010 at 12:54 PM, Jimmy Larsson <[email protected]> wrote:
>
>>
>> Hi
>>
>> I am trying some zone based firewall configurations am getting confused.
>> My background is that I am very familiar with Pix/ASA and not very familiar
>> at all with the Firewall-features of IOS. Therefore I always compare these
>> which gets me confused.
>>
>> Now I´ve done a simple 2-zone firewall out of my 3-legged router. My goal
>> is this:
>> * Allow all outbound telnet stateful
>> * Allow all icmp-echos initiated from inside (and ofcourse the
>> corresponding echo replies)
>> * Deny everything else between the zones.
>>
>> I have configured the two zones and a policy-map that inspects and allows
>> my outbound telnet. It looks like this:
>>
>>
>>
>> class-map type inspect match-any class-INSIDE-TO-OUTSIDE
>>  match protocol telnet
>> !
>> !
>> policy-map type inspect policy-INSIDE-TO-OUTSIDE
>>  class type inspect class-INSIDE-TO-OUTSIDE
>>   inspect
>>  class class-default
>>   drop
>> !
>> zone security OUTSIDE
>> zone security INSIDE
>> zone-pair security INSIDE-TO-OUTSIDE source INSIDE destination OUTSIDE
>>  service-policy type inspect policy-INSIDE-TO-OUTSIDE
>>
>>
>> interface FastEthernet0
>>  description Outside
>>  zone-member security OUTSIDE
>> !
>> interface FastEthernet1
>>  description Inside
>>  zone-member security INSIDE
>> !
>> interface Vlan13
>>  zone-member security INSIDE
>> !
>>
>> So, now I can telnet from outside to telnet. But what about the icmp:s? My
>> idea was to create a class-map referring to an acl that defines non-stateful
>> outbound-traffic that should be allowed. Something like this:
>>
>> ip access-list extended acl-INSIDE-TO-OUTSIDE-no-inspect
>>  permit icmp any any eq echo
>>
>> class-map class-INSIDE-TO-OUTSIDE-no-inspect
>>  match access-group acl-INSIDE-TO-OUTSIDE-no-inspect
>>
>> But when trying to apply this to my policy-map (my goal was to do
>> "pass"-action on this) I get this error:
>> r1(config-pmap)#class class-INSIDE-TO-OUTSIDE-no-inspect
>> % class class-INSIDE-TO-OUTSIDE-no-inspect of type default is not allowed
>> in policy-map policy-INSIDE-TO-OUTSIDE of type inspect
>>
>> In what way am I thinking wrong here?
>>
>> Also, in my scenario, how should my interface acl:s look like when doing
>> this zone-thing? Since traffic between zones are blocked by default and
>> traffic inside a zone is permitted, I guess that I should´nt have any
>> interface acl:s since all transit traffic security is taken care of by the
>> zone-configuration. Right? Can there be any situation where interface acl:s
>> are needed when doing ZBFW?
>>
>> Thanks in advance!
>> --
>> -------
>> Jimmy Larsson
>> Ryavagen 173
>> s-26030 Vallakra
>> Sweden
>> http://blogg.kvistofta.nu
>> -------
>>
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>> visit www.ipexpert.com
>>
>>
>
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