Anyconnect client not getting return traffic.

[prakkdangc]

Hi All,

I have setup AnyConnect on an ASA and after successful authentication from the client, no traffic passes from the firewall to the client. I only get packages sent, not recieved. The client is sucessfully getting an address from the local pool, but cannot go anyhere.

The firewall log shows inside connections being built .. but that's it!

TIA

Dave

[Jennifer Halim]

Can you please share the ASA configuration so we can confirm if it's configuration or other issues?

Also, please kindly ensure that you have configure NAT exemption between the internal subnets and the ip pool subnet.

Also, ensure that your internal host that you are trying to access from the AnyConnect does not have Windows firewall or any other firewall that might prevent inbound access from different subnet. if you do, try to turn it off and see if that works.

[prakkdangc]

Thanks for your help!

Here is a sanitized version of the config. I may have been overzelous editing it.

ASA Version 8.2(4)
!
hostname hidden

names
dns-guard
!
interface GigabitEthernet0/0
nameif outside
security-level 0
ip address 2.2.2.2 255.255.255.0
!
interface GigabitEthernet0/1
speed 100
duplex full
nameif inside
security-level 100
ip address 1.1.1.1 255.255.255.0
!
!
interface Management0/0
shutdown
nameif management
security-level 100
no ip address
management-only
!
banner motd ********************************************************************************
banner motd *  Access to Northrop Grumman's computer network ("Network") is only for       *
banner motd *  authorized users and for authorized purposes. Transmission via the          *
banner motd *  Network of export controlled information abroad or to a foreign person in   *
banner motd *  the U.S. is an export which requires U.S. Government export authorization.  *
banner motd *  You have no expectation of privacy in any information passing through or    *
banner motd *  stored on the Network. Communications and data that pass through or are     *
banner motd *  stored on this Network are monitored and may be intercepted, searched,      *
banner motd *  disclosed or used for any lawful purpose.                                   *
banner motd ********************************************************************************
boot system disk0:/asa824-k8.bin
ftp mode passive
clock timezone EST -5
clock summer-time EDT recurring
dns domain-lookup outside
dns domain-lookup inside
dns domain-lookup dmz
dns server-group DefaultDNS
name-server 10.10.10.10
name-server 11.11.11.11
name-server 90.90.90.90
domain-name hidden.com

object-group service web-ports tcp
port-object eq www
port-object eq https
object-group service Auth-Svcs-TCP tcp
port-object eq domain
port-object eq 135
port-object eq ldap
port-object eq 445
port-object eq ldaps
port-object range 3268 3269
port-object range 61000 61001
port-object eq 88
port-object eq 5723
port-object eq 5724
port-object range 5000 5100

access-list inside-nonat remark NAT return traffic for Anyconnect
access-list inside-nonat extended permit ip any 10.241.66.0 255.255.255.0
access-list outside_nat0_outbound extended deny ip 10.241.66.0 255.255.255.0 any
pager lines 24
logging enable
logging timestamp
logging buffered informational
logging trap informational
logging asdm informational
logging device-id hostname
no logging message 302021
no logging message 302020
mtu outside 1500
mtu inside 1500
mtu dmz 1500
mtu Auth-DMZ 1500
mtu Sandbox 1500
mtu management 1500
ip local pool AnyConnectPool 10.241.66.2-10.241.66.254 mask 255.255.255.0

no failover
icmp unreachable rate-limit 1 burst-size 1
asdm image disk0:/asdm-641.bin
no asdm history enable
arp timeout 14400
global (outside) 1 2.2.2.2

nat (outside) 0 access-list outside_nat0_outbound outside
nat (inside) 0 access-list inside-nonat
nat (inside) 1 access-list nat-pptp-gre
nat (inside) 2 0.0.0.0 0.0.0.0

access-group acl-outside in interface outside
access-group acl-inside in interface inside

route outside 0.0.0.0 0.0.0.0 2.2.2.2 1
route inside 0.0.0.0 0.0.0.0 100.100.100.100 tunneled
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
dynamic-access-policy-record DfltAccessPolicy
webvpn
  svc ask enable default svc
aaa-server Kerberos protocol kerberos
max-failed-attempts 5
aaa-server Kerberos (inside) host 12.12.12.12
kerberos-realm hidden.COM
aaa-server TACACS+ protocol tacacs+
aaa-server TACACS+ (inside) host 145.145.145.145
key *****
aaa-server TACACS+ (inside) host 211.211.211.211
key *****
aaa-server ActivIdentity protocol radius
aaa-server ActivIdentity (inside) host 111.111.111.111
timeout 15
key *****
authentication-port 1812
accounting-port 1813
radius-common-pw *****
aaa-server ActivIdentity (inside) host 145.145.145.145
timeout 15
key *****
authentication-port 1812
accounting-port 1813
radius-common-pw *****

snmp-server community *****
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto map outside_map 15 match address Xerox-Crypto
crypto map outside_map 15 set pfs
crypto map outside_map 15 set peer 4.4.4.4
crypto map outside_map 15 set transform-set ESP-3DES-SHA
crypto map outside_map 15 set security-association lifetime seconds 28800
crypto map outside_map 15 set security-association lifetime kilobytes 4608000
crypto map outside_map interface outside
crypto isakmp identity hostname
crypto isakmp enable outside
crypto isakmp policy 10
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
crypto isakmp policy 20
authentication pre-share
encryption 3des
hash md5
group 2
lifetime 86400
crypto isakmp policy 30
authentication pre-share
encryption 3des
hash md5
group 1
lifetime 86400
crypto isakmp policy 40
authentication pre-share
encryption 3des
hash md5
group 1
lifetime 28800
no vpn-addr-assign dhcp

webvpn
enable outside
enable inside
anyconnect-essentials
svc image disk0:/anyconnect-dart-win-2.5.0217-k9.pkg 1
svc profiles AnyConnectProfile disk0:/anyconnectprofile.xml
svc enable
tunnel-group-list enable
group-policy DfltGrpPolicy attributes
wins-server value 11.11.11.11 43.43.43.43
dns-server value 10.10.10.10 43.43.43.43
vpn-tunnel-protocol IPSec l2tp-ipsec svc webvpn
default-domain value hidden2.com
msie-proxy method no-proxy
address-pools value AnyConnectPool
webvpn
  svc profiles value AnyConnectProfile
  svc ask enable
group-policy GroupPolicy2 internal
group-policy GroupPolicy2 attributes
vpn-tunnel-protocol svc
default-domain value hidden2.com
group-policy GroupPolicy1 internal
group-policy GroupPolicy1 attributes
vpn-tunnel-protocol svc webvpn
default-domain value hidden2.com
username local_pix password 0xMBVlT7IbeHbFIk encrypted privilege 15
tunnel-group 3.3.3.3 type ipsec-l2l
tunnel-group 3.3.3.3 ipsec-attributes
pre-shared-key *****
tunnel-group "AnyConnect - ActivIdentity" type remote-access
tunnel-group "AnyConnect - ActivIdentity" general-attributes
address-pool AnyConnectPool
authentication-server-group ActivIdentity
default-group-policy GroupPolicy1
tunnel-group "AnyConnect - ActivIdentity" webvpn-attributes
group-alias ActivIdentity enable
group-alias AnyConnect- disable
tunnel-group "AnyConnect - Kerberos" type remote-access
tunnel-group "AnyConnect - Kerberos" general-attributes
address-pool AnyConnectPool
authentication-server-group Kerberos
default-group-policy GroupPolicy1
tunnel-group "AnyConnect - Kerberos" webvpn-attributes
group-alias Kerberos enable
!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns migrated_dns_map_1
parameters
  message-length maximum 512
policy-map global_policy
class inspection_default
  inspect dns migrated_dns_map_1
  inspect ftp
  inspect h323 h225
  inspect h323 ras
  inspect rsh
  inspect rtsp
  inspect esmtp
  inspect sqlnet
  inspect skinny 
  inspect sunrpc
  inspect xdmcp
  inspect sip 
  inspect netbios
  inspect tftp
  inspect icmp
  inspect pptp
  inspect icmp error
  inspect ip-options
!
service-policy global_policy global
prompt hostname context

[Jennifer Halim]

The following is incorrect, not required and should be removed:

nat (outside) 0 access-list outside_nat0_outbound outside

Also, you have the following config:

route inside 0.0.0.0 0.0.0.0 100.100.100.100 tunneled

which means, all VPN traffic after being decrypted will be routed to 100.100.100.100. Is this what you are trying to achieve?

If yes, then pls make sure that your internal router knows to route the VPN client pool subnet (10.241.66.0/24) towards the ASA inside interface. Otherwise, you will see no return traffic back towards the AnyConnect client if it's not being pointed towards the ASA inside interface.

[prakkdangc]

Hi,

I removed the nat (outside) 0 access-list outside_nat0_outbound outside and made sure the next hop router had a route pointing to the inside interface of the firewall for the 10.241.66.0/24 subnet. I also did an "ip any any" for that subnet in both directions on the firewall. No go. Still, the recieve counter on the client gets exactly 807 packets during the tunnel setup, but none after - unless I ping my client from the firewall. That works and will increment the RX counter.

BTW .. my firewall is off on the PC, but I tested with two others with the same results.

Is there any more data I can get you?

Thanks,

Dave

[Jennifer Halim]

A topology diagram would be great to understand where the networks are and also how is the internal router connected.

Also please advise which internal subnets you are trying to reach from the AnyConnect client.

Also try turning on: management-access inside

and see if you ping the ASA inside interface from the AnyConnect client.

[prakkdangc]

Hi Jennifer,

Yes I can ping the inside interface of the firewall, but not the default gateway of the tunnel traffic.

I will get a  diagram to you, but I don't want it shared. Will that be a problem?

Dave

[Jennifer Halim · Accepted solution]

If you can ping the ASA, but not the gateway, that means the gateway doesn't know how to route back towards the AnyConnect ip pool subnet.

Please check the gateway and make sure it has route towards the ASA inside interface for the AnyConnect pool subnet.