I'm having a hard time diagnosing an issue with DNS resolution across an IPSEC VPN. This setup was working at one time but now it's not. I have a 5505 with easyvpn connecting to a VPN concentrator (cisco 3000), and the workstation shows that DNS is set to my internal corp DNS server, the DNS server is pingable, I can even telnet across VPN to the internal DNS server on port 53, but it will not resolve anything. When I do an nslookup it times out. I don't understand what is causing the failure as this setup was working once before. I see the DNS UDP packets hitting the asa 5505 on the way out, but sniffing on the DNS server I never see the queries arrive. This issue is occuring to mulitple workstations all using the same config below in different regions. Both internal and external resolution are failing. Please assist. Thanks!
Example config on ASA 5505
hostname ASA5505
domain-name xxxxx
enable pass
passwd encrypted
names
!
interface Vlan1
nameif inside
security-level 100
ip address 192.168.11.113 255.255.255.240
!
interface Vlan2
nameif outside
security-level 0
ip address dhcp setroute
!
interface Ethernet0/0
switchport access vlan 2
!
interface Ethernet0/1
!
interface Ethernet0/2
!
interface Ethernet0/3
!
interface Ethernet0/4
!
interface Ethernet0/5
!
interface Ethernet0/6
!
interface Ethernet0/7
!
ftp mode passive
clock timezone CST -6
clock summer-time CDT recurring
dns server-group DefaultDNS
domain-name xxxx
pager lines 24
logging enable
logging buffer-size 16000
logging buffered informational
logging asdm informational
mtu inside 1500
mtu outside 1500
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 1 0.0.0.0 0.0.0.0
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
http server enable
http 10.0.0.0 255.0.0.0 inside
http 192.168.1.0 255.255.255.0 inside
http 192.168.11.0 255.255.255.0 inside
no snmp-server location
no snmp-server contact
snmp-server communit xxxx
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
telnet 10.0.0.0 255.0.0.0 inside
telnet 192.168.11.0 255.255.255.0 inside
telnet timeout 5
ssh 10.0.0.0 255.0.0.0 inside
ssh timeout 5
console timeout 30
management-access inside
dhcpd lease 86400
dhcpd domain xxxxx
dhcpd auto_config outside
dhcpd option 150 ip 10.20.20.11 10.20.20.12
!
dhcpd address 192.168.11.114-192.168.11.125 inside
dhcpd dns 10.20.16.4 10.20.16.3 interface inside
dhcpd domain xxxxx interface inside
dhcpd enable inside
!
vpnclient server xxxxx
vpnclient mode network-extension-mode
vpnclient nem-st-autoconnect
vpnclient vpngroup HomeNetworkVPN password xxxxxx
vpnclient username xxxxx password xxxxxx
vpnclient enable
threat-detection basic-threat
threat-detection statistics host
threat-detection statistics port
threat-detection statistics protocol
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
ntp server 10.20.0.1 source inside prefer
webvpn
username xxxx passwordxxxxxx encrypted privilege 15
!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
parameters
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
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
!
service-policy global_policy global
prompt hostname context
