01-27-2024 02:57 PM - edited 01-27-2024 04:25 PM
I'm trying to put an ASA5550 between my ISP's modem and my internal network (just my laptop, to start with). From the ASA console, I can ping out to the internet (e.g. 8.8.8.8), but not from the laptop. My laptop can't even ping the ISP gateway, though it can ping the ASA port it's connected to. Can anyone please tell me what I've done wrong?
My ISP gateway is 10.0.0.1 and is connected to interface g1/0 (outside) on the ASA. My laptop is connected to g0/0 (inside) and is getting address 10.99.0.100 from DHCP on the ASA.
ciscoasa# show interface g0/0
Interface GigabitEthernet0/0 "inside", is up, line protocol is up
Hardware is i82546GB rev03, BW 1000 Mbps, DLY 10 usec
Auto-Duplex(Full-duplex), Auto-Speed(1000 Mbps)
Input flow control is unsupported, output flow control is off
Description: LAN interface
MAC address 001b.d454.f12a, MTU 1500
IP address 10.99.0.1, subnet mask 255.255.255.0
...
ciscoasa# show interface g1/0
Interface GigabitEthernet1/0 "outside", is up, line protocol is up
Hardware is VCS7380 rev01, BW 1000 Mbps, DLY 10 usec
Auto-Duplex(Full-duplex), Auto-Speed(1000 Mbps)
Input flow control is unsupported, output flow control is off
Media-type configured as RJ45 connector
Description: WAN interface
MAC address 6400.f182.579e, MTU 1500
IP address 10.0.0.254, subnet mask 255.255.255.0
...
ciscoasa# show route
...
Gateway of last resort is 10.0.0.1 to network 0.0.0.0
C 10.0.0.0 255.255.255.0 is directly connected, outside
C 10.99.0.0 255.255.255.0 is directly connected, inside
S* 0.0.0.0 0.0.0.0 [1/0] via 10.0.0.1, outside
ciscoasa# show run dhcpd
dhcpd address 10.99.0.100-10.99.0.200 inside
dhcpd enable inside
ciscoasa# ping 8.8.8.8
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 8.8.8.8, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 10/12/20 ms
Solved! Go to Solution.
01-27-2024 07:25 PM
@renenkel hi you need to configure route in your ISP router to tell about your internal network or use NAT in ASA to translate traffic towards internet.
01-28-2024 01:10 AM
How are you testing from your PC? Are you just using ping or are you also trying to browse to webpages (assuming you have DNS configured)?
Verify that you have ICMP inspection configured with show run policy-map to allow ping packets throught the ASA. If it is not configured add it.
policy-map global_policy
class inspection_default
inspect icmp
01-28-2024 02:45 PM - edited 01-28-2024 02:47 PM
Thanks so much to everyone who helped!
So, to summarize, I had to do two things:
- configure NAT to translate inside addresses to the internet ( @Kasun Bandara )
- inspect ICMP to allow pings through the ASA ( @Marius Gunnerud , @MHM Cisco World )
01-27-2024 07:25 PM
@renenkel hi you need to configure route in your ISP router to tell about your internal network or use NAT in ASA to translate traffic towards internet.
01-27-2024 08:54 PM
Thanks Kasun -- I tried this but it still doesn't work... @Kasun Bandara
ciscoasa(config)# object network inside-subnet
ciscoasa(config-network-object)# subnet 10.99.0.0 255.255.255.0
ciscoasa(config-network-object)# nat (inside,outside) dynamic interface
ciscoasa(config-network-object)# exit
ciscoasa(config)# exit
ciscoasa# show nat
Auto NAT Policies (Section 2)
1 (inside) to (outside) source dynamic inside-subnet interface
translate_hits = 10, untranslate_hits = 22
01-27-2024 09:17 PM
@renenkel can you share the out put for 'sh run nat'
01-27-2024 09:28 PM - edited 01-27-2024 09:45 PM
ciscoasa# sh run nat
!
object network inside-subnet
nat (inside,outside) dynamic interface
ciscoasa#
01-27-2024 09:57 PM
@renenkel can you share the output of 'asa(config)# sh xlate type dynamic' while trying to access internet? also do you have ASDM?
01-28-2024 01:43 PM
@Kasun BandaraI haven't been able to get ASDM working -- app from ASA seems incompatible with Windows 10, even in compatibility mode. Below is output of sh xlate type dynamic while pinging 8.8.8.8 from internal host.
ciscoasa(config)# sh xlate type dynamic
13 in use, 15 most used
Flags: D - DNS, e - extended, I - identity, i - dynamic, r - portmap,
s - static, T - twice, N - net-to-net
ICMP PAT from inside:10.99.0.100/40989 to outside:10.0.0.254/40989 flags ri idle 0:00:03 timeout 0:00:30
UDP PAT from inside:10.99.0.100/55960 to outside:10.0.0.254/55960 flags ri idle 0:01:23 timeout 0:00:30
UDP PAT from inside:10.99.0.100/50993 to outside:10.0.0.254/50993 flags ri idle 0:01:24 timeout 0:00:30
UDP PAT from inside:10.99.0.100/52990 to outside:10.0.0.254/52990 flags ri idle 0:01:25 timeout 0:00:30
UDP PAT from inside:10.99.0.100/62721 to outside:10.0.0.254/62721 flags ri idle 0:01:34 timeout 0:00:30
UDP PAT from inside:10.99.0.100/59119 to outside:10.0.0.254/59119 flags ri idle 0:01:34 timeout 0:00:30
UDP PAT from inside:10.99.0.100/59398 to outside:10.0.0.254/59398 flags ri idle 0:01:39 timeout 0:00:30
UDP PAT from inside:10.99.0.100/57913 to outside:10.0.0.254/57913 flags ri idle 0:01:52 timeout 0:00:30
UDP PAT from inside:10.99.0.100/58919 to outside:10.0.0.254/58919 flags ri idle 0:01:52 timeout 0:00:30
UDP PAT from inside:10.99.0.100/57181 to outside:10.0.0.254/57181 flags ri idle 0:01:53 timeout 0:00:30
UDP PAT from inside:10.99.0.100/64723 to outside:10.0.0.254/64723 flags ri idle 0:00:00 timeout 0:00:30
UDP PAT from inside:10.99.0.100/52382 to outside:10.0.0.254/52382 flags ri idle 0:00:00 timeout 0:00:30
UDP PAT from inside:10.99.0.100/63117 to outside:10.0.0.254/63117 flags ri idle 0:00:05 timeout 0:00:30
01-28-2024 12:18 AM
Did you add icmp inspection?
You need icmp inspection for any icmp passthrough asa
MHM
01-27-2024 11:52 PM
What ASA Code running on this ASA ? - show version (give you information)
Configuration commands for older version of ASA Code
ASA5(config)#
global (outside) 1 interface
nat (inside) 1 10.99.0.0 255.255.255.0
Configuration commands for version 8.3 or Newer
ASA5(config)#
object network OBJ_NAT_LAN
subnet 10.99.0.0 255.255.255.0
nat (inside,outside) dynamic interface
On the PC - can you post ipconfig /all
Still you have an issue - post show run (full removing password information)
01-28-2024 02:02 PM
ciscoasa> show version
Cisco Adaptive Security Appliance Software Version 9.1(6)
Device Manager Version 7.9(2)152
The commands I used are like what you give for version 8.3 or newer:
ciscoasa(config)# object network inside-subnet
ciscoasa(config-network-object)# subnet 10.99.0.0 255.255.255.0
ciscoasa(config-network-object)# nat (inside,outside) dynamic interface
Here is output of ipconfig /all from PC:
C:\WINDOWS\system32>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : Thinkstation
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
Ethernet adapter Local Area Connection 2:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet #2
Physical Address. . . . . . . . . : 70-F3-95-02-0D-99
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Broadcom NetXtreme Gigabit Ethernet
Physical Address. . . . . . . . . : 70-F3-95-02-0D-98
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::c59e:1f34:3b87:3d5f%13(Preferred)
IPv4 Address. . . . . . . . . . . : 10.99.0.101(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : January-28-24 4:46:36 PM
Lease Expires . . . . . . . . . . : January-28-24 5:49:51 PM
Default Gateway . . . . . . . . . : 10.99.0.1
DHCP Server . . . . . . . . . . . : 10.99.0.1
DHCPv6 IAID . . . . . . . . . . . : 242283413
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1A-CB-85-84-70-F3-95-02-0D-98
DNS Servers . . . . . . . . . . . : 2620:10a:80bb::20
2620:10a:80bc::20
149.112.121.20
149.112.122.20
NetBIOS over Tcpip. . . . . . . . : Enabled
Ethernet adapter Ethernet:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : TAP-NordVPN Windows Adapter V9
Physical Address. . . . . . . . . : 00-FF-A3-53-D7-9C
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Here is output of show run from ASA:
ciscoasa(config)# show run
: Saved
:
: Serial Number: JMX1131L1X0
: Hardware: ASA5550, 4096 MB RAM, CPU Pentium 4 3000 MHz
:
ASA Version 9.1(6)
!
hostname ciscoasa
xlate per-session deny tcp any4 any4
xlate per-session deny tcp any4 any6
xlate per-session deny tcp any6 any4
xlate per-session deny tcp any6 any6
xlate per-session deny udp any4 any4 eq domain
xlate per-session deny udp any4 any6 eq domain
xlate per-session deny udp any6 any4 eq domain
xlate per-session deny udp any6 any6 eq domain
names
!
interface GigabitEthernet0/0
description LAN interface
nameif inside
security-level 100
ip address 10.99.0.1 255.255.255.0
!
interface GigabitEthernet0/1
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet0/2
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet0/3
shutdown
no nameif
no security-level
no ip address
!
interface Management0/0
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet1/0
description WAN interface
nameif outside
security-level 0
ip address 10.0.0.254 255.255.255.0
!
interface GigabitEthernet1/1
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet1/2
shutdown
no nameif
no security-level
no ip address
!
interface GigabitEthernet1/3
shutdown
no nameif
no security-level
no ip address
!
ftp mode passive
object network inside-subnet
subnet 10.99.0.0 255.255.255.0
pager lines 24
mtu inside 1500
mtu outside 1500
no failover
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
no arp permit-nonconnected
!
object network inside-subnet
nat (inside,outside) dynamic interface
route outside 0.0.0.0 0.0.0.0 10.0.0.1 1
timeout xlate 3:00:00
timeout pat-xlate 0:00:30
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
user-identity default-domain LOCAL
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart warmstart
crypto ipsec security-association pmtu-aging infinite
crypto ca trustpool policy
telnet 10.99.0.0 255.255.255.0 inside
telnet timeout 2
ssh stricthostkeycheck
ssh timeout 5
ssh key-exchange group dh-group1-sha1
console timeout 0
dhcpd address 10.99.0.100-10.99.0.200 inside
dhcpd enable inside
!
!
tls-proxy maximum-session 1000
!
threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
anyconnect-essentials
!
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 dns preset_dns_map
inspect ftp
inspect h323 h225
inspect h323 ras
inspect ip-options
inspect netbios
inspect rsh
inspect rtsp
inspect skinny
inspect esmtp
inspect sqlnet
inspect sunrpc
inspect tftp
inspect sip
inspect xdmcp
!
service-policy global_policy global
prompt hostname context
no call-home reporting anonymous
call-home
profile CiscoTAC-1
no active
destination address http https://tools.cisco.com/its/service/oddce/services/DDCEService
destination address email callhome@cisco.com
destination transport-method http
subscribe-to-alert-group diagnostic
subscribe-to-alert-group environment
subscribe-to-alert-group inventory periodic monthly
subscribe-to-alert-group configuration periodic monthly
subscribe-to-alert-group telemetry periodic daily
01-28-2024 01:10 AM
How are you testing from your PC? Are you just using ping or are you also trying to browse to webpages (assuming you have DNS configured)?
Verify that you have ICMP inspection configured with show run policy-map to allow ping packets throught the ASA. If it is not configured add it.
policy-map global_policy
class inspection_default
inspect icmp
01-28-2024 02:08 PM - edited 01-28-2024 02:38 PM
@Marius GunnerudSo far I only tried pinging 8.8.8.8 from the PC, which hasn't worked. Here's the output of show run policy-map:
ciscoasa(config)# show run policy-map
!
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 dns preset_dns_map
inspect ftp
inspect h323 h225
inspect h323 ras
inspect ip-options
inspect netbios
inspect rsh
inspect rtsp
inspect skinny
inspect esmtp
inspect sqlnet
inspect sunrpc
inspect tftp
inspect sip
inspect xdmcp
!
ciscoasa(config)#
Oh, wait a minute....ICMP isn't there. Adding it....
ciscoasa(config)# policy-map global_policy
ciscoasa(config-pmap)# class inspection_default
ciscoasa(config-pmap-c)# inspect icmp
Yay!!! Now it works!
C:\WINDOWS\system32>ping 8.8.8.8
Pinging 8.8.8.8 with 32 bytes of data:
Reply from 8.8.8.8: bytes=32 time=19ms TTL=117
Reply from 8.8.8.8: bytes=32 time=12ms TTL=117
Reply from 8.8.8.8: bytes=32 time=14ms TTL=117
Thanks Marius!!!
01-28-2024 02:37 PM
for ping to work through the firewall, you need to add inspect icmp to the class inspection_default under policy-map global-policy.
01-28-2024 02:40 PM
Nice! Glad we could help.
01-28-2024 02:45 PM - edited 01-28-2024 02:47 PM
Thanks so much to everyone who helped!
So, to summarize, I had to do two things:
- configure NAT to translate inside addresses to the internet ( @Kasun Bandara )
- inspect ICMP to allow pings through the ASA ( @Marius Gunnerud , @MHM Cisco World )
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