The aaa server command is what makes the difference. I didn't use the management command in lab 20 and it works. But what you did is good practice.
Regards, Tyson Scott CCIE # 13513 (R&S, Security, SP) Managing Partner/Technical Instructor - IPexpert Inc. [email protected] ----- Reply message ----- From: "Andrei Lucian Coman" <[email protected]> Date: Sun, Apr 17, 2011 3:31 am Subject: [OSL | CCIE_Security] ASA-generated traffic thru lan2lan-tunnel? To: "Andrew Wurster" <[email protected]> Cc: "OSL Security" <[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 > >
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