Solved: Open ports on ASA 5505 for VoIP

ematelyan · ‎05-06-2013

Hello,

I'm working on setting up a PBX server in our office, and I'm having trouble getting a port opened for SIP on my ASA 5505.

I created static NAT rule for SIP traffic from internal server to the outside IP address.

I created access rules on outside interface to forward port 5060 to internal PBX server (192.168.1.8)

I also disabled sip packet inspection on the ASA.

I'm still receiving a message from the PBX that the firewall is configured incorrectly. Am I missing something?

Result of the command: "show run"

: Saved
:
ASA Version 8.2(5)
!
hostname WayneASA

!
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
!
interface Vlan1
nameif inside
security-level 100
ip address 192.168.1.1 255.255.255.0
!
interface Vlan2
nameif outside
security-level 0
ip address 70.91.18.205 255.255.255.252
!
interface Vlan5
shutdown
no nameif
security-level 50
ip address 192.168.10.1 255.255.255.0
!
ftp mode passive
clock timezone EST -5
clock summer-time EDT recurring
dns domain-lookup inside
dns domain-lookup outside
dns server-group DefaultDNS
name-server 75.75.75.75
name-server 75.75.76.76
domain-name 3gtms.com
object-group protocol TCPUDP
protocol-object udp
protocol-object tcp
access-list inside_access_in extended permit ip any any
access-list IPSec_Access extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list inside_nat0 extended permit ip 192.168.1.0 255.255.255.0 192.168.10.0 255.255.255.224
access-list inside_nat0 extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list inside_nat0 extended permit ip 192.168.1.0 255.255.255.0 192.168.5.0 255.255.255.0
access-list TunnelSplit1 standard permit 192.168.10.0 255.255.255.224
access-list TunnelSplit1 standard permit 192.168.1.0 255.255.255.0
access-list outside_1_cryptomap extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list outside_2_cryptomap extended permit ip 192.168.1.0 255.255.255.0 192.168.5.0 255.255.255.0
access-list outside_cryptomap extended permit ip 192.168.1.0 255.255.255.0 192.168.5.0 255.255.255.0
access-list RemoteTunnel_splitTunnelAcl standard permit 192.168.1.0 255.255.255.0
access-list RemoteTunnel_splitTunnelAcl_1 standard permit 192.168.1.0 255.255.255.0
access-list out_access_in extended permit udp any host 192.168.1.8 eq sip
access-list out_access_in extended permit tcp any host 192.168.1.8 eq 5000
access-list out_access_in extended permit udp any host 192.168.1.8 range 9000 9049
access-list out_access_in extended permit tcp any host 192.168.1.8 eq sip
access-list out_access_in extended permit object-group TCPUDP any host 192.168.1.8 eq 5090
pager lines 24
logging enable
mtu inside 1500
mtu outside 1500
ip local pool VPNPool 192.168.10.1-192.168.10.30 mask 255.255.255.224
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list inside_nat0
nat (inside) 1 0.0.0.0 0.0.0.0
static (inside,outside) tcp interface sip 192.168.1.8 sip netmask 255.255.255.255
static (inside,outside) udp interface sip 192.168.1.8 sip netmask 255.255.255.255
access-group inside_access_in in interface inside
access-group out_access_in in interface outside
route outside 0.0.0.0 0.0.0.0 70.91.18.206 1
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
timeout floating-conn 0:00:00
dynamic-access-policy-record DfltAccessPolicy
aaa authentication ssh console LOCAL
http server enable
http 0.0.0.0 0.0.0.0 inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-DES-SHA esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-MD5 esp-des esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-MD5 esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-SHA esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-MD5 esp-aes esp-md5-hmac
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec transform-set VPNTransformSet esp-3des esp-md5-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set pfs group1
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set transform-set ESP-AES-128-SHA ESP-AES-128-MD5 ESP-AES-192-SHA ESP-AES-192-MD5 ESP-AES-256-SHA ESP-AES-256-MD5 ESP-3DES-SHA ESP-3DES-MD5 ESP-DES-SHA ESP-DES-MD5
crypto map VPNMap 1 ipsec-isakmp dynamic DynamicMap
crypto map IPSec_map 1 match address IPSec_Access
crypto map IPSec_map 1 set peer 50.199.234.229
crypto map IPSec_map 1 set transform-set VPNTransformSet
crypto map IPSec_map 2 match address outside_2_cryptomap
crypto map IPSec_map 2 set pfs group1
crypto map IPSec_map 2 set peer 98.101.139.210
crypto map IPSec_map 2 set transform-set VPNTransformSet
crypto map IPSec_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map IPSec_map interface outside
crypto map outside_map 1 match address outside_1_cryptomap
crypto map outside_map 1 set peer 50.199.234.229
crypto ca trustpoint _SmartCallHome_ServerCA
crl configure
crypto isakmp enable outside
crypto isakmp policy 1
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 43200
telnet 192.168.1.0 255.255.255.0 inside
telnet timeout 5
ssh 0.0.0.0 0.0.0.0 inside
ssh timeout 60
console timeout 0
management-access inside
dhcpd auto_config outside
!
dhcpd address 192.168.1.100-192.168.1.199 inside
dhcpd dns 75.75.75.75 75.75.76.76 interface inside
dhcpd enable inside
!

threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
group-policy RemoteTunnel internal
group-policy RemoteTunnel attributes
dns-server value 75.75.75.75 75.75.76.76
vpn-tunnel-protocol IPSec
split-tunnel-policy tunnelspecified
split-tunnel-network-list value RemoteTunnel_splitTunnelAcl_1
default-domain value 3gtms.com
username eric password 0vcSd5J/TLsFy7nU encrypted privilege 15
tunnel-group RemoteTunnel type remote-access
tunnel-group RemoteTunnel general-attributes
address-pool VPNPool
default-group-policy RemoteTunnel
tunnel-group RemoteTunnel ipsec-attributes
pre-shared-key *****
tunnel-group 50.199.234.229 type ipsec-l2l
tunnel-group 50.199.234.229 ipsec-attributes
pre-shared-key *****
tunnel-group 98.101.139.210 type ipsec-l2l
tunnel-group 98.101.139.210 ipsec-attributes
pre-shared-key *****
!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
policy-map global_policy
class inspection_default
inspect icmp
inspect ftp
inspect h323 h225
inspect h323 ras
inspect rsh
inspect rtsp
inspect esmtp
inspect sqlnet
inspect skinny
inspect sunrpc
inspect xdmcp
inspect netbios
inspect tftp
inspect ip-options
inspect dns
inspect pptp
!
service-policy global_policy global
prompt hostname context
call-home reporting anonymous
Cryptochecksum:ac23c6d2ae16c72c52eaae22fa14905b
: end

sokakkar · ‎05-06-2013

Eric- That is correct, either you add static PAT rule for all ports or add a one to one static NAT instead as range of ports is not supported on this version.

Range of ports in NAT is supported from ASA 8.3 onwards. But that is a major upgrade and requires additional h/w memory in some cases. NAT config has changed as well and also the way ASA handles the interface acls. More details are available here:

https://supportforums.cisco.com/docs/DOC-12690

-

Sourav

View solution in original post

sokakkar · ‎05-06-2013

Hi Eric,

To start with access-list has incorrect IP:

access-list out_access_in extended permit udp any host 192.168.1.8 eq sip

access-list out_access_in extended permit tcp any host 192.168.1.8 eq 5000

access-list out_access_in extended permit udp any host 192.168.1.8 range 9000 9049

access-list out_access_in extended permit tcp any host 192.168.1.8 eq sip

access-list out_access_in extended permit object-group TCPUDP any host 192.168.1.8 eq 5090

Instead of inside PBX IP, you need to allow traffic for interface IP as that is the IP which is visible to internet:

access-list out_access_in extended permit udp any host 70.91.18.205 eq sip

access-list out_access_in extended permit tcp any host 70.91.18.205 eq 5000

access-list out_access_in extended permit udp any host 70.91.18.205 range 9000 9049

access-list out_access_in extended permit tcp any host 70.91.18.205 eq sip

access-list out_access_in extended permit object-group TCPUDP any host 70.91.18.205 eq 5090

Moreover, translation is available only for TCP/UDP 5060 and none of the other ports which are needed for your PBX to work:

static (inside,outside) tcp interface sip 192.168.1.8 sip netmask 255.255.255.255

static (inside,outside) udp interface sip 192.168.1.8 sip netmask 255.255.255.255

And there is no way to open port range in static port forwarding on your current ASA s/w version.

Fix the access-list as shown above and apply SIP inspection which can open pin holes for the RTP:

policy-map global_policy

class inspection_default

inspect sip

exit

Info on SIP inspection:

http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a008081042c.shtml#sip

This link from config guide outlines few scenarios where SIP inspection won't work with static PAT:

http://www.cisco.com/en/US/docs/security/asa/asa82/configuration/guide/inspect_voicevideo.html#wp1439430

You might need to configured a one to one static NAT for PBX. If static PAT conditions above don't apply and it doesn't work with inspect SIP and fixed acl, I would recommend opening a TAC case as we might need to review the captures and debugs in detail to figure this out.

-

Sourav

ematelyan · ‎05-06-2013

Hello,

I modified the access-lists as you mentioned, and turned on SIP inspection.

The firewall check on my PBX says that port 5060 is configured correctly, but the rest are not.

I added a static rule for TCP/UDP on port 5090 to test, and ran the firewall check again.

It then said that port 5090 is configured correctly.

So it looks like it needs a static rule for each port. There's no way to add a static nat for ranges? Do I need to upgrade my ASA version for this? Or is there an alternate solution?

Result of the command: "show run"

: Saved
:
ASA Version 8.2(5)
!
hostname WayneASA

!
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
!
interface Vlan1
nameif inside
security-level 100
ip address 192.168.1.1 255.255.255.0
!
interface Vlan2
nameif outside
security-level 0
ip address 70.91.18.205 255.255.255.252
!
interface Vlan5
shutdown
no nameif
security-level 50
ip address 192.168.10.1 255.255.255.0
!
ftp mode passive
clock timezone EST -5
clock summer-time EDT recurring
dns domain-lookup inside
dns domain-lookup outside
dns server-group DefaultDNS
name-server 75.75.75.75
name-server 75.75.76.76
domain-name 3gtms.com
object-group protocol TCPUDP
protocol-object udp
protocol-object tcp
access-list inside_access_in extended permit ip any any
access-list IPSec_Access extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list inside_nat0 extended permit ip 192.168.1.0 255.255.255.0 192.168.10.0 255.255.255.224
access-list inside_nat0 extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list inside_nat0 extended permit ip 192.168.1.0 255.255.255.0 192.168.5.0 255.255.255.0
access-list TunnelSplit1 standard permit 192.168.10.0 255.255.255.224
access-list TunnelSplit1 standard permit 192.168.1.0 255.255.255.0
access-list outside_1_cryptomap extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0
access-list outside_2_cryptomap extended permit ip 192.168.1.0 255.255.255.0 192.168.5.0 255.255.255.0
access-list outside_cryptomap extended permit ip 192.168.1.0 255.255.255.0 192.168.5.0 255.255.255.0
access-list RemoteTunnel_splitTunnelAcl standard permit 192.168.1.0 255.255.255.0
access-list RemoteTunnel_splitTunnelAcl_1 standard permit 192.168.1.0 255.255.255.0
access-list out_access_in extended permit udp any host 70.91.18.205 eq sip
access-list out_access_in extended permit tcp any host 70.91.18.205 eq 5000
access-list out_access_in extended permit udp any host 70.91.18.205 range 9000 9049
access-list out_access_in extended permit tcp any host 70.91.18.205 eq sip
access-list out_access_in extended permit object-group TCPUDP any host 70.91.18.205 eq 5090
pager lines 24
logging enable
mtu inside 1500
mtu outside 1500
ip local pool VPNPool 192.168.10.1-192.168.10.30 mask 255.255.255.224
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list inside_nat0
nat (inside) 1 0.0.0.0 0.0.0.0
static (inside,outside) tcp interface sip 192.168.1.8 sip netmask 255.255.255.255
static (inside,outside) udp interface sip 192.168.1.8 sip netmask 255.255.255.255
static (inside,outside) tcp interface 5090 192.168.1.8 5090 netmask 255.255.255.255
static (inside,outside) udp interface 5090 192.168.1.8 5090 netmask 255.255.255.255
access-group inside_access_in in interface inside
access-group out_access_in in interface outside
route outside 0.0.0.0 0.0.0.0 70.91.18.206 1
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
timeout floating-conn 0:00:00
dynamic-access-policy-record DfltAccessPolicy
aaa authentication ssh console LOCAL
http server enable
http 0.0.0.0 0.0.0.0 inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-DES-SHA esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-MD5 esp-des esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-MD5 esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-SHA esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-MD5 esp-aes esp-md5-hmac
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec transform-set VPNTransformSet esp-3des esp-md5-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set pfs group1
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set transform-set ESP-AES-128-SHA ESP-AES-128-MD5 ESP-AES-192-SHA ESP-AES-192-MD5 ESP-AES-256-SHA ESP-AES-256-MD5 ESP-3DES-SHA ESP-3DES-MD5 ESP-DES-SHA ESP-DES-MD5
crypto map VPNMap 1 ipsec-isakmp dynamic DynamicMap
crypto map IPSec_map 1 match address IPSec_Access
crypto map IPSec_map 1 set peer 50.199.234.229
crypto map IPSec_map 1 set transform-set VPNTransformSet
crypto map IPSec_map 2 match address outside_2_cryptomap
crypto map IPSec_map 2 set pfs group1
crypto map IPSec_map 2 set peer 98.101.139.210
crypto map IPSec_map 2 set transform-set VPNTransformSet
crypto map IPSec_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map IPSec_map interface outside
crypto map outside_map 1 match address outside_1_cryptomap
crypto map outside_map 1 set peer 50.199.234.229

crypto isakmp enable outside
crypto isakmp policy 1
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 43200
telnet 192.168.1.0 255.255.255.0 inside
telnet timeout 5
ssh 0.0.0.0 0.0.0.0 inside
ssh timeout 60
console timeout 0
management-access inside
dhcpd auto_config outside
!
dhcpd address 192.168.1.100-192.168.1.199 inside
dhcpd dns 75.75.75.75 75.75.76.76 interface inside
dhcpd enable inside
!

threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
group-policy RemoteTunnel internal
group-policy RemoteTunnel attributes
dns-server value 75.75.75.75 75.75.76.76
vpn-tunnel-protocol IPSec
split-tunnel-policy tunnelspecified
split-tunnel-network-list value RemoteTunnel_splitTunnelAcl_1
default-domain value 3gtms.com
username eric password 0vcSd5J/TLsFy7nU encrypted privilege 15
tunnel-group RemoteTunnel type remote-access
tunnel-group RemoteTunnel general-attributes
address-pool VPNPool
default-group-policy RemoteTunnel
tunnel-group RemoteTunnel ipsec-attributes
pre-shared-key *****
tunnel-group 50.199.234.229 type ipsec-l2l
tunnel-group 50.199.234.229 ipsec-attributes
pre-shared-key *****
tunnel-group 98.101.139.210 type ipsec-l2l
tunnel-group 98.101.139.210 ipsec-attributes
pre-shared-key *****
!
class-map inspection_default
match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
policy-map global_policy
class inspection_default
inspect icmp
inspect ftp
inspect h323 h225
inspect h323 ras
inspect rsh
inspect rtsp
inspect esmtp
inspect sqlnet
inspect skinny
inspect sunrpc
inspect xdmcp
inspect netbios
inspect tftp
inspect ip-options
inspect dns
inspect pptp
inspect sip
!
service-policy global_policy global
prompt hostname context
call-home reporting anonymous
Cryptochecksum:7818c22a0087fce0c252083f1c0f2e20
: end

sokakkar · ‎05-06-2013

Eric- That is correct, either you add static PAT rule for all ports or add a one to one static NAT instead as range of ports is not supported on this version.

Range of ports in NAT is supported from ASA 8.3 onwards. But that is a major upgrade and requires additional h/w memory in some cases. NAT config has changed as well and also the way ASA handles the interface acls. More details are available here:

https://supportforums.cisco.com/docs/DOC-12690

-

Sourav

ematelyan · ‎05-06-2013

Well it was much simpler for me to just create an excel sheet with the commands for the 50 static NATs, and add them to the command line. This resolved the issue, and the firewall seems to be working correctly now. Thank you!

sokakkar · ‎05-06-2013

Awesome! Glad to know that it worked! :-)

-

Sourav