The "inside" interface is connected to the LAN and the "outside" interface
is connected to the WAN and terminates the IPSec tunnel.


On Sun, Apr 17, 2011 at 9:00 PM, Jimmy Larsson <[email protected]> wrote:

> And the "inside" interface is not the one that terminates you ipsec-tunnel?
>
> /Jimmy
>
> 2011/4/17 Andrei Lucian Coman <[email protected]>
>
>> This is my topology:
>>
>> CS-ACS server <--> Local ASA <-- IPSec tunnel --> Remote ASA
>>
>> Maybe it's version-dependant, but in this topology, with ASA OS 8.2(2) or
>> 8.2(4), and with the configuration outlined in my previous email, I'm
>> looking in the CS-ACS server access logs and I see the requests coming from
>> the remote ASA inside interface.
>>
>> Andrei
>>
>>
>> On Sun, Apr 17, 2011 at 8:31 PM, Jimmy Larsson <[email protected]>wrote:
>>
>>>
>>> Sorry, I dont follow. Whats your topology?
>>>
>>> Are you saying that you can source your tacacs+-packets from another
>>> interface than the one closest to the tacacs+-server? And thru a vpn-tunnel?
>>> Because my experience so far is that you cannot choose source-interface in
>>> any way. But i´d very much like to be over-conviced. :-)
>>>
>>> /Jimmy
>>>
>>> 2011/4/17 Andrei Lucian Coman <[email protected]>
>>>
>>>> Hey guys,
>>>>
>>>> I have two ASA's in a production networks configured with the same
>>>> requirement: one of the ASA should authenticate with a tacacs+ server
>>>> located behind the other ASA, using the existing IPSec tunnel between the
>>>> ASA's. This is how they both are configured:
>>>>
>>>> management-access inside
>>>> aaa-server CS-ACS protocol tacacs+
>>>> aaa-server CS-ACS (inside) host 192.168.254.10
>>>>
>>>> I think that "management-access inside" makes the difference. I'm pretty
>>>> sure that this works, because:
>>>>
>>>> 1. Looking at the CS-ACS passed authentication logs, I can see the
>>>> authentication requests coming from the inside interface of the remote ASA.
>>>> 2. The remote ASA falls back to local authentication when the WAN link
>>>> is down.
>>>>
>>>> Can someone test this in a lab?
>>>>
>>>>
>>>> Andrei Lucian Coman
>>>>
>>>>
>>>> On Thu, Apr 14, 2011 at 11:36 PM, Andrew Wurster <
>>>> [email protected]> wrote:
>>>>
>>>>> oh true i forgot about that aaa server interface.  that specifies the
>>>>> interface to egress to reach the aaa server.  so yes in your case specify
>>>>> the outside interface there and also that interface's address in your 
>>>>> crypto
>>>>> acls and you should be golden.  i am 99.9% sure you need to specify both 
>>>>> of
>>>>> those things using the outside interface.
>>>>>
>>>>> keep us posted.
>>>>> On Apr 14, 2011 12:59 PM, "Jimmy Larsson" <[email protected]> wrote:
>>>>> > Cool! This is mu gut feeling aswell, but I have never tried it. One
>>>>> question
>>>>> > is regarding the interface-relation when defining a radius-server. If
>>>>> I look
>>>>> > at the ASA-syntax it saids:
>>>>> >
>>>>> > ciscoasa(config)# aaa-server RAD ?
>>>>> >
>>>>> > configure mode commands/options:
>>>>> > ( Open parenthesis for the name of the network
>>>>> > interface
>>>>> > where the designated AAA server is accessed
>>>>> > deadtime Specify the amount of time that will elapse between
>>>>> > the
>>>>> > disabling of the last server in the group and the
>>>>> > subsequent re-enabling of all servers
>>>>> > host Enter this keyword to specify the IP address for the
>>>>> > server
>>>>> > max-failed-attempts Specify the maximum number of failures that will
>>>>> be
>>>>> > allowed for any server in the group before that
>>>>> > server
>>>>> > is deactivated
>>>>> > protocol Enter the protocol for a AAA server group
>>>>> >
>>>>> > In my world there is really no need for defining an interface for
>>>>> this since
>>>>> > it´s "all about routing". Given that the radius-server ip is x.x.x.x
>>>>> and
>>>>> > there is a rout for x.x.x.x, why defining an interface? My own
>>>>> feeling about
>>>>> > this is that this is for defining the source ip for outbound radius
>>>>> packets.
>>>>> > But looking at the syntax help above the interface-relationship is
>>>>> only a
>>>>> > way to define where to send the traffic (which in my world could be
>>>>> done
>>>>> > just by using the routing table).
>>>>> >
>>>>> > So you are saying that I should define my remote radius-server as
>>>>> (outside)?
>>>>> > Another hypothesis I had (if I were right regarding the
>>>>> interface-definition
>>>>> > above) was to use (inside) so that the radius-packets were sourced
>>>>> from the
>>>>> > inside ip and thereby included in the "normal" crypto-acl defining
>>>>> > inside-LAN-2-Inside-Lan (and sending it via outside only because of
>>>>> the
>>>>> > default route).
>>>>> >
>>>>> > Two theories. Mine is probably wrong. I will also lab it up quite
>>>>> soon if
>>>>> > noone else here knows for sure. ;)
>>>>> >
>>>>> > Thanks for your input!
>>>>> >
>>>>> > /Jimmy Larsson
>>>>> >
>>>>> >
>>>>> > 2011/4/14 Andrew Wurster <[email protected]>
>>>>> >
>>>>> >> jimmy -
>>>>> >>
>>>>> >> as bruno said - it's possible :) .
>>>>> >>
>>>>> >> think about it from a routing perspective. know that the crypto
>>>>> happens as
>>>>> >> the traffic is pushed towards the egress interface (post nat). this
>>>>> is true
>>>>> >> for routers and firewalls, but on firewall we choose the local
>>>>> address based
>>>>> >> on routing only, so we usually have no "source address" or looback
>>>>> interface
>>>>> >> selection commands like we do on the routers (think local-address
>>>>> for the
>>>>> >> crypto map commands in IOS).
>>>>> >>
>>>>> >> SO... you're most likely going to assume it will be sourced using
>>>>> the
>>>>> >> outside interface IP address. so all you've got to do is add the
>>>>> traffic
>>>>> >> between ASA1's outside interface IP address to the internal radius
>>>>> server
>>>>> >> behind ASA2. AND THEN of course you've got to tell your SNMP server
>>>>> that
>>>>> >> the client is at the public outside interface IP address (for
>>>>> instance
>>>>> >> 20.20.20.20) and not the private inside one. AND ALSO if you're
>>>>> doing NAT -
>>>>> >> make sure to exempt the NAT from the SNMP server to the new host
>>>>> address.
>>>>> >> it's all about the layers baby!!!
>>>>> >>
>>>>> >> so it might look something like:
>>>>> >>
>>>>> >> !!! ASA1 !!!
>>>>> >> access-list CRYPTO_ACL extend permit ip host 20.20.20.20 host
>>>>> 192.168.2.10
>>>>> >>
>>>>> >> !!! ASA2 !!!
>>>>> >> access-list CRYPTO_ACL extend permit ip host 192.168.2.10 host
>>>>> 20.20.20.20
>>>>> >> access-list NO_NAT extend permit ip host 192.168.2.10 host
>>>>> 20.20.20.20
>>>>> >>
>>>>> >> and bingo bango (hopefully)... give it a shot and let us know. i'll
>>>>> try to
>>>>> >> lab it up for you this weekend if i have time.
>>>>> >>
>>>>> >> cheers,
>>>>> >>
>>>>> >> andrew
>>>>> >>
>>>>> >> On Thu, Apr 14, 2011 at 11:36 AM, Jimmy Larsson <
>>>>> [email protected]>wrote:
>>>>> >>
>>>>> >>> Hi guys
>>>>> >>>
>>>>> >>> I have a question that I have tried to find time to lab out myself
>>>>> without
>>>>> >>> success so I am throwing it out here in hope for a quick answer.
>>>>> >>>
>>>>> >>> Lets say that my ASA1 has a Lan2Lan-tunnel to ASA2. On the inside
>>>>> of ASA2
>>>>> >>> is a radius-server and ASA1 needs to authenticate vpn-clients on
>>>>> that radius
>>>>> >>> server. Can I do that thru the vpn-tunnel? And if so, how do I
>>>>> define the
>>>>> >>> crypto acl and which interface should I specify in ASA1 that the
>>>>> >>> radius-server resides on?
>>>>> >>>
>>>>> >>> Topology:
>>>>> >>>
>>>>> >>> Radius-server .10 on Lan2 192.168.2.0/24 -----(.1) ASA2
>>>>> =====VPN-tunnel
>>>>> >>> over internet=====ASA1 .1 --- Lan1 192.168.1.0/24
>>>>> >>>
>>>>> >>> How do I configure aaa-server for radius on ASA1?
>>>>> >>>
>>>>> >>> Thanks in advance!
>>>>> >>>
>>>>> >>> Best regards
>>>>> >>> Jimmy Larsson
>>>>> >>>
>>>>> >>>
>>>>> >>> --
>>>>> >>> -------
>>>>> >>> Jimmy Larsson
>>>>> >>> Ryavagen 173
>>>>> >>> s-26030 Vallakra
>>>>> >>> Sweden
>>>>> >>> http://blogg.kvistofta.nu
>>>>> >>> -------
>>>>> >>>
>>>>> >>> _______________________________________________
>>>>> >>> For more information regarding industry leading CCIE Lab training,
>>>>> please
>>>>> >>> visit www.ipexpert.com
>>>>> >>>
>>>>> >>>
>>>>> >>
>>>>> >
>>>>> >
>>>>> > --
>>>>> > -------
>>>>> > Jimmy Larsson
>>>>> > Ryavagen 173
>>>>> > s-26030 Vallakra
>>>>> > Sweden
>>>>> > http://blogg.kvistofta.nu
>>>>> > -------
>>>>>
>>>>> _______________________________________________
>>>>> For more information regarding industry leading CCIE Lab training,
>>>>> please visit www.ipexpert.com
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> -------
>>> Jimmy Larsson
>>> Ryavagen 173
>>> s-26030 Vallakra
>>> Sweden
>>> http://blogg.kvistofta.nu
>>> -------
>>>
>>
>>
>
>
> --
> -------
> Jimmy Larsson
> Ryavagen 173
> s-26030 Vallakra
> Sweden
> http://blogg.kvistofta.nu
> -------
>
_______________________________________________
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