01-06-2009 03:29 PM
Hello,
We have a Cisco PIX 515 with software 7.1(2). It accepts Cisco VPN Client connections without any problem, but no routing is performed towards the internal networks directly connected to the PIX. For instance, my PC is assigned IP address 172.16.2.57 and, then, internal Windows server 172.16.0.12 does not answer ping or RDP attempts. The most irritating thing is that these attempts are registered in Syslog, but always terminated with "SYN timeout", as follows:
2009-01-06 23:23:01 Local4.Info 217.15.42.214 %PIX-6-302013: Built inbound TCP connection 3315917 for outside:172.16.2.57/1283 (172.16.2.57/1283) to inside:ALAI2/3389 (ALAI2/3389)
2009-01-06 23:23:31 Local4.Info 217.15.42.214 %PIX-6-302014: Teardown TCP connection 3315917 for outside:172.16.2.57/1283 to inside:ALAI2/3389 duration 0:00:30 bytes 0 SYN Timeout
2009-01-06 23:23:31 Local4.Debug 217.15.42.214 %PIX-7-609002: Teardown local-host outside:172.16.2.57 duration 0:00:30
We tried to enable and disable "nat-control", "same-security-traffic permit inter-interface" and "same-security-traffic permit intra-interface" but results are the same: the VPN connection completes successfully but remote clients cannot reach the internal servers.
I'm attaching the relevant configurations to fully understand the problem:
interface Ethernet0
speed 100
duplex full
nameif outside
security-level 0
ip address xx.yy.zz.tt 255.255.255.240
!
interface Ethernet1
nameif inside
security-level 100
ip address 172.16.0.1 255.255.255.0
!
access-list inside_nat0_outbound extended permit ip 172.16.0.0 255.255.255.0 172.16.2.56 255.255.255.248
!
access-list outside_cryptomap_dyn_20 extended permit ip 172.16.0.0 255.255.255.0 172.16.2.56 255.255.255.248
!
access-list VPN_client_group_splitTunnelAcl standard permit 172.16.0.0 255.255.255.0
!
ip local pool pool_vpn_clientes 172.16.2.57-172.16.2.62 mask 255.255.255.248
!
nat-control
global (outside) 12 xx.yy.zz.tt
nat (inside) 0 access-list inside_nat0_outbound
nat (inside) 12 172.16.0.12 255.255.255.255
!
group-policy VPN_clientes internal
group-policy VPN_clientes attributes
default-domain value xxyyzz.net
group-policy VPN_client_group internal
group-policy VPN_client_group attributes
split-tunnel-policy tunnelspecified
split-tunnel-network-list value VPN_client_group_splitTunnelAcl
default-domain value xxyyzz.local
!
I'm not attaching any cryptographic algorithms details because the VPN is completed successfully, as I said at the beginning. Besides, routing tables are not relevant in my opinion, because the unreachable hosts are directly connected to the internal LAN of the PIX 515.
Thank you very much.
Solved! Go to Solution.
01-06-2009 03:47 PM
can you confirm asa have NAT traversal enable, if not, enable it in asa and have vpn clients try again.
PIX/ASA 7.1 and earlier
pix(config)#isakmp nat-traversal 20
PIX/ASA 7.2(1) and later
pix(config)#crypto isakmp nat-traversal 20
01-06-2009 03:47 PM
can you confirm asa have NAT traversal enable, if not, enable it in asa and have vpn clients try again.
PIX/ASA 7.1 and earlier
pix(config)#isakmp nat-traversal 20
PIX/ASA 7.2(1) and later
pix(config)#crypto isakmp nat-traversal 20
01-07-2009 02:49 PM
Great, Jorge!
nat-traversal was enough to solve the problem. Routing to internal servers is working now for remote VPN clients.
Thank you very much!
01-08-2009 03:09 PM
Comu, glad it was resolved and pleasure to hepl.. thanks for rating.
Regards
Jorge
01-15-2009 03:20 AM
test
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