cisco-asa-5505.md 15 KB
CISCO ASA 5505
ciscoasa# show version
factory defaults
? configure factory-default confreg 0x2040 relo
reset password
on console, during boot, hit ESC, enter ROMMON mode
confreg 0x41 boot
disable rebooting to normal state again
ciscoasa(config)# config-register 0x1
after reboot, password is empty, set enable's password
(very strong password, use different admin user to process changes)
enable password (password)
set hostname, print label, attach to device
hostname (hostname)
enter config mode
enable configure terminal
no callhome, please
(config)# clear configure call-home (config)# no service call-home
set clock
ciscoasa# show clock ciscoasa# clock set 07:29:00 May 06 2019 ciscoasa(config)# clock timezone UTC +3
if DST presents
ciscoasa(config)# clock summer-time MST recurring 1 Sunday April 2:00 last Sunday October 2:00
set NTP
ntp server ip_address [ key key_id ] [ source interface_name ] [ prefer ]
hostname(config)# ntp server 10.1.1.1 key 1 prefer sh ntp associations sh ntp status
configure DNS
Enables the ASA to send DNS requests to a DNS server to perform a name lookup for supported commands.
dns domain-lookup interface_name
hostname(config)# dns domain-lookup inside
Specifies the DNS server group that the ASA uses for outgoing requests.
dns server-group DefaultDNS
hostname(config)# dns server-group DefaultDNS
Specifies one or more DNS servers. You can enter all six IP addresses in the same command, separated by spaces,
name-server ip_address [ip_address2] [...] [ip_address6]
hostname(config-dns-server-group)# name-server 10.1.1.5 192.168.1.67 209.165.201.6
disable call-home function
Enable Management Access with ASDM
[Location of ASDM image on the ASA]
ASA(config)# asdm image disk0:/asdm-647.bin
[Enable the http server on the device ]
ASA(config)# http server enable
[Tell the device which IP addresses are allowed to connect with HTTP (ASDM)]
ASA(config)# http 10.10.10.0 255.255.255.0 inside
[Configure user/pass to login with ASDM]
ASA(config)# username admin password adminpass
DHCP (Assign IP addresses to computers from the ASA device)
[Create a DHCP address pool to assign to clients. This address pool must be on the same subnet as the ASA interface]
ciscoasa(config)# dhcpd address 192.168.1.101-192.168.1.110 inside
[The DNS servers to assign to clients via DHCP]
ciscoasa(config)# dhcpd dns 8.8.8.8 8.8.8.8
[Enable the DHCP server on the inside interface]
ciscoasa(config)# dhcpd enable inside
Permit Traffic Between Same Security Levels
[Permits communication between different interfaces that have the same security level.]
ciscoasa(config)# same-security-traffic permit inter-interface
[Permits traffic to enter and exit the same interface.]
ciscoasa(config)# same-security-traffic permit intra-interface
Useful Verification and Troubleshooting Commands
[Shows hit-counts on ACL with name “OUTSIDE-IN”. It shows how many hits each entry has on the ACL]
ciscoasa# show access-list OUTSIDE-IN Sample output: access-list OUTSIDE-IN line 1 extended permit tcp 100.100.100.0 255.255.255.0 10.10.10.0 255.255.255.0 eq telnet (hitcnt=15) 0xca10ca21
[The show conn command displays the number of active TCP and UDP connections, and provides information about connections of various types.]
ciscoasa# show conn
[Shows all the connections through the appliance]
ciscoasa# show conn all
[Shows HTTP GET, H323, and SIP connections that are in the “up” state]
ciscoasa# show conn state up,http_get,h323,sip
[Shows overall connection counts]
ciscoasa# show conn count 54 in use, 123 most used
[show CPU utilization]
ciscoasa# show cpu usage
[List the contents of the internal flash disk of the ASA]
ciscoasa# show disk
[Displays operating information about hardware system components such as CPU, fans, power supply, temperature etc]
ciscoasa# show environment
[Displays maximum physical memory and current free memory]
ciscoasa# show memory
Displays information about Active/Standby failover status
ciscoasa# show failover
[Shows information about Interfaces, such as line status, packets received/sent, IP address etc]
ciscoasa# show interface
[Displays the network states of local hosts. A local-host is created for any host that forwards traffic to, or through, the ASA.]
ciscoasa# show local-host
[Displays the routing table]
ciscoasa# show route
[Displays information about NAT sessions]
ciscoasa# show xlate
show configs
ciscoasa# show startup-config ciscoasa# show running-config
save configs to memory
ciscoasa# copy run start Source filename [running-config] ?
[enter] to confirm
or (will not ask source)
ciscoasa# write memory
enable logging
ASA(config)# logging enable ASA(config)# logging timestamp ASA(config)# logging buffer-size 65536 ASA(config)# logging buffered warnings ASA(config)# logging asdm errors
send to syslog, if needed
ASA(config)# logging host inside 192.168.1.30 ASA(config)# logging trap errors
permit local aaa
hostname(config)# aaa authorization exec authentication-server
add user
username (username) nopassword
list users
change password of user
username (username) password (password)
delete user
give user privileges
username (username) password (password) privilege 15 username (username) attributes ciscoasa(config-username)# service-type admin ciscoasa(config-username)# service-type nas-prompt ciscoasa(config-username)# service-type remote-access ciscoasa(config-username)# exit
add ssh access
ASA#configure terminal ASA(config)#domain-name local.local
ASA(config)#aaa authentication ssh console LOCAL
ciscoasa(config)#aaa authentication ssh console LOCAL
aaa authentication ssh console LOCAL
ciscoasa(config)#crypto key generate rsa modulus 2048
ASA(config)#crypto key generate rsa general-keys modulus 1024
ASA(config)#ssh 192.168.1.10 255.255.255.255 inside ASA(config)#ssh 0.0.0.0 0.0.0.0 OUTSIDE
verify which encryptions are enabled
connect via ssh (some routers use SSH1)
show ssh
Image Software Management
[Copy image file from TFTP to Flash of ASA]
ciscoasa# copy tftp flash
copy file to USB
download file (firmware, config) from device
upload file
copy file from USB
upgrade firmware
[At next reboot, the firewall will use the software image “asa911-k8.bin” from flash]
ciscoasa(config)# boot system flash:/asa911-k8.bin
show interfaces
show interface ip brief show switch vlan
set up interfaces for VLAN interfaces (example: outside-inside)
ciscoasa(config)# interface Vlan 10 ciscoasa(config-if)# nameif outside ciscoasa(config-if)# security-level 80 ciscoasa(config-if)# ip address 192.168.100.77 255.225.255.0 ciscoasa(config-if)# no shutdown ciscoasa(config-if)# exit
ciscoasa(config)# interface Vlan 20 ciscoasa(config-if)# nameif lab5 ciscoasa(config-if)# security-level 90 ciscoasa(config-if)# ip address 192.168.2.1 255.225.255.0 ciscoasa(config-if)# no shutdown ciscoasa(config-if)# exit
ciscoasa(config)# interface Ethernet 0/0 ciscoasa(config-if)# no nameif ciscoasa(config-if)# no security-level ciscoasa(config-if)# no ip address ciscoasa(config-if)# switchport access vlan 10 ciscoasa(config-if)# no shutdown ciscoasa(config-if)# exit
(same for 0/6 PoE, deskphone)
ciscoasa(config)# interface Ethernet 0/6
Step 5: Configure PAT on the outside interface
ASA5505(config)# global (outside) 1 interface ASA5505(config)# nat (inside) 1 0.0.0.0 0.0.0.0
for ASA 8.3 and later:
object network obj_any subnet 0.0.0.0 0.0.0.0 nat (inside,outside) dynamic interface
to check PoE status
show power inline
configure interface to use DHCP client and set default route provided
ciscoasa(config-if)# ip address dhcp setroute
show nameif
trunk port
show interfaces trunk (config-if)#interface gigabitEthernet 0/23 (config-if)#description Trunk port to (host) (config-if)#switchport mode trunk (config-if)#switchport trunk allowed vlan all (config-if)#switchport trunk allowed vlan 2-4094 no shutdown
access port
(config)#interface gigabitEthernet 0/23 (config-if)#description (host) (config-if)#switchport mode access (config-if)#switchport access vlan 128 (config-if)#no shutdown
or
ciscoasa(config)# interface Ethernet 0/1 ciscoasa(config-if)# no nameif ciscoasa(config-if)# no security-level ciscoasa(config-if)# no ip address ciscoasa(config-if)# switchport access 20 ciscoasa(config-if)# no shutdown ciscoasa(config-if)# exit
Static and Default Routes
MORE READING: Cisco ASA Firewall in Transparent Layer2 Mode
[Configure a default route via the “outside” interface with gateway IP of 100.1.1.1 ]
ciscoasa(config)# route outside 0.0.0.0 0.0.0.0 100.1.1.1
routing (traffic to modem of ISP)
ciscoasa(config-if)# route outside 0.0.0.0 0.0.0.0 192.168.100.1 1
[Configure a static route via the “inside” interface. To reach network 192.168.2.0/24 go via gateway IP 192.168.1.1 ]
ciscoasa(config)# route inside 192.168.2.0 255.255.255.0 192.168.1.1
same level security traffic
hostname(config)# same-security-traffic permit inter-interface
The absolutely necessary Interface Sub-commands that you need to configure in order for the interface to pass traffic are the following:
Assigns a name to an interface
nameif “interface name”
Assigns an IP address to the interface
ip address “ip_address” “subnet_mask”
Assigns a security level to the interface
security-level “number 0 to 100”
By default all interfaces are shut down, so enable them.
no shutdown
Network Address Translation (NAT)
[Configure PAT for internal LAN (192.168.1.0/24) to access the Internet using the outside interface] ciscoasa(config)# object network internal_lan ciscoasa(config-network-object)# subnet 192.168.1.0 255.255.255.0 ciscoasa(config-network-object)# nat (inside,outside) dynamic interface
[Configure PAT for all (“any”) networks to access the Internet using the outside interface]
ciscoasa(config)# object network obj_any ciscoasa(config-network-object)# subnet 0.0.0.0 0.0.0.0 ciscoasa(config-network-object)# nat (any,outside) dynamic interface
[Configure static NAT. The private IP 192.168.1.1 in DMZ will be mapped statically to public IP 100.1.1.1 in outside zone]
ciscoasa(config)# object network web_server_static ciscoasa(config-network-object)# host 192.168.1.1 ciscoasa(config-network-object)# nat (DMZ , outside) static 100.1.1.1
[Configure static Port NAT. The private IP 192.168.1.1 in DMZ will be mapped statically to public IP 100.1.1.1 in outside zone only for port 80]
ciscoasa(config)# object network web_server_static ciscoasa(config-network-object)# host 192.168.1.1 ciscoasa(config-network-object)# nat (DMZ , outside) static 100.1.1.1 service tcp 80 80
FIREWALL
Access Control Lists (ACL)
show
show run access-list (host) show access-list (host)
[Apply the ACL above at the “outside” interface for traffic coming “in” the interface]
ciscoasa(config)# access-group OUTSIDE_IN in interface outside ciscoasa(config)# access-group INSIDE_IN in interface inside
[Create an ACL to allow TCP access from “any” source IP to host 192.168.1.1 port 80]
ciscoasa(config)# access-list OUTSIDE_IN extended permit tcp any host 192.168.1.1 eq 80
[Create an ACL to deny all traffic from host 192.168.1.1 to any destination and allow everything else. This ACL is then applied at the “inside” interface for traffic coming “in” the interface]
ciscoasa(config)# access-list INSIDE_IN extended deny ip host 192.168.1.1 any ciscoasa(config)# access-list INSIDE_IN extended permit ip any any
Object Groups
[Create a network group having two hosts (192.168.1.1 and 192.168.1.2). This group can be used in other configuration commands such as ACLs]
ciscoasa(config)# object-group network WEB_SRV ciscoasa(config-network)# network-object host 192.168.1.1 ciscoasa(config-network)# network-object host 192.168.1.2
[Create a network group having two subnets (10.1.1.0/24 and 10.2.2.0/24). This group can be used in other configuration commands such as ACLs]
ciscoasa(config)# object-group network DMZ_SUBNETS ciscoasa(config-network)# network-object 10.1.1.0 255.255.255.0 ciscoasa(config-network)# network-object 10.2.2.0 255.255.255.0
[Create a service group having several ports. This group can be used in other configuration commands such as ACLs]
ciscoasa(config)# object-group service DMZ_SERVICES tcp ciscoasa(config-service)# port-object eq http ciscoasa(config-service)# port-object eq https ciscoasa(config-service)# port-object range 21 23
[Example of using object groups in ACLs]
ciscoasa(config)# access-list OUTSIDE-IN extended permit tcp any object-group DMZ_SUBNETS object-group DMZ_SERVICES
create group
(config)# object-group network (hostgroup)
add object into group
(config-network-object-group)# network-object object (newhost)
show objects
show object-group network exit
edit objects
object network (newhost) host (ip)
CISCO FIREWALL:
enable SSH
https://www.opentechguides.com/how-to/article/cisco/39/Cisco-configure-ssh.html
CHECKING EXISTING
show running-config | include (ip-from) show running-config | include (ip-to) show access-list outside_in show run | include (ip) show (ip)
interfaces
show interfaces status
access-groups
show configuration | include access-group ip access-group access-list-name {in | out} no ip access-group access-list-name {in | out}
let host out:
access-list (zone) extended permit udp host (ip) host (ip) eq (port) access-list (zone) extended permit tcp host (ip) host (ip) eq (port) access-list (zone) extended permit tcp any4 host (ip) eq https
write configuration
wr (copy running-config startup-config) wr write mem
capturing
capture capin interface outside match tcp host (host) host (host) eq (port) show capture show capture capin
general commands
show run | include route
enable unsupported tranceiver
service unsupported-transceiver no errdisable detect cause gbic-invalid
save (commit)
write mem
set up VPN
[show details about IPSEC VPNs like packets encrypted/decrypted, tunnel peers etc]
ciscoasa# show crypto ipsec sa
[show details if an IPSEC VPN tunnel is up or not. MM_ACTIVE means the tunnel is up]
ciscoasa# show crypto isakmp sa
sources:
https://www.cisco.com/c/en/us/td/docs/security/asa/asa82/configuration/guide/config.html https://www.cisco.com/c/en/us/td/docs/security/asa/asa82/configuration/guide/config/access_aaa.html
https://www.cisco.com/c/en/us/td/docs/security/asa/asa92/configuration/general/asa-general-cli/interface-basic-5505.pdf https://www.cisco.com/c/en/us/td/docs/security/asa/asa91/configuration/general/asa_91_general_config/route_static.pdf
Books: