cisco-asa.md 14 KB
CISCO ASA 5505
ciscoasa# show version
factory defaults
? configure factory-default confreg 0x2040 relo
disable call-home function
Enable Management Access with ASDM ASA(config)# asdm image disk0:/asdm-647.bin [Location of ASDM image on the ASA] ASA(config)# http server enable [Enable the http server on the device ] ASA(config)# http 10.10.10.0 255.255.255.0 inside [Tell the device which IP addresses are allowed to connect with HTTP (ASDM)] ASA(config)#username admin password adminpass [Configure user/pass to login with ASDM]
DHCP
DHCP (Assign IP addresses to computers from the ASA device) ciscoasa(config)# dhcpd address 192.168.1.101-192.168.1.110 inside [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 dns 209.165.201.2 209.165.202.129 [The DNS servers to assign to clients via DHCP] ciscoasa(config)# dhcpd enable inside [Enable the DHCP server on the inside interface]
Permit Traffic Between Same Security Levels ciscoasa(config)# same-security-traffic permit inter-interface [Permits communication between different interfaces that have the same security level.] ciscoasa(config)# same-security-traffic permit intra-interface [Permits traffic to enter and exit the same interface.]
Useful Verification and Troubleshooting Commands ciscoasa# show access-list OUTSIDE-IN [Shows hit-counts on ACL with name “OUTSIDE-IN”. It shows how many hits each entry has on the ACL]
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
ciscoasa# show conn [The show conn command displays the number of active TCP and UDP connections, and provides information about connections of various types.] ciscoasa# show conn all [Shows all the connections through the appliance] ciscoasa# show conn state up,http_get,h323,sip [Shows HTTP GET, H323, and SIP connections that are in the “up” state] ciscoasa# show conn count 54 in use, 123 most used [Shows overall connection counts]
ciscoasa# show cpu usage [show CPU utilization] ciscoasa# show disk [List the contents of the internal flash disk of the ASA] ciscoasa# show environment [Displays operating information about hardware system components such as CPU, fans, power supply, temperature etc] ciscoasa# show memory [Displays maximum physical memory and current free memory]
ciscoasa# show failover [Displays information about Active/Standby failover status] ciscoasa# show interface [Shows information about Interfaces, such as line status, packets received/sent, IP address etc] ciscoasa# show local-host [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 route [Displays the routing table]
ciscoasa# show xlate [Displays information about NAT sessions]
reset password
on console, during boot, hit ESC, enter ROMMON mode
confreg 0x41 boot
after reboot, password is empty, set enable's password
(very strong password, use different admin user to process changes)
enable password (password)
enter config mode
enable configure terminal
show configs
ciscoasa# show startup-config ciscoasa# show running-config
set hostname, print label, attach to device
hostname (hostname)
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
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
save configs to memory
ciscoasa# copy run start Source filename [running-config] ?
[enter] to confirm
or (will not ask source)
ciscoasa# write memory
add user
username (username) nopassword username (username) password (password)
permit local aaa
hostname(config)# aaa authorization exec authentication-server
list users
change password of user
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
crypto key generate rsa modulus 2048
ASA(config)#crypto key generate rsa general-keys modulus 1024
crypto key generate rsa modulus modulus_size
ciscoasa(config)# crypto key generate rsa modulus 2048 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
show ssh
connect via ssh (some routers use (old) SSH1)
download file (firmware, config) from device
Image Software Management ciscoasa# copy tftp flash [Copy image file from TFTP to Flash of ASA] ciscoasa#config term ciscoasa(config)# boot system flash:/asa911-k8.bin [At next reboot, the firewall will use the software image “asa911-k8.bin” from flash]
upload file
copy file to USB
copy file from USB
upgrade firmware
show interfaces
show interface ip brief show switch vlan
set up 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 10 ciscoasa(config-if)# no shutdown ciscoasa(config-if)# exit
(same for 0/6 PoE, deskphone)
ciscoasa(config)# interface Ethernet 0/6
to check PoE status
show power inline
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
routing (traffic to modem of ISP)
ciscoasa(config-if)# route outside 0.0.0.0 0.0.0.0 192.168.100.1 1
same level security traffic
hostname(config)# same-security-traffic permit inter-interface
set up VPN
ciscoasa# show crypto ipsec sa [show details about IPSEC VPNs like packets encrypted/decrypted, tunnel peers etc] ciscoasa# show crypto isakmp sa [show details if an IPSEC VPN tunnel is up or not. MM_ACTIVE means the tunnel is up]
The absolutely necessary Interface Sub-commands that you need to configure in order for the interface to pass traffic are the following:
nameif “interface name”: Assigns a name to an interface
ip address “ip_address” “subnet_mask” : Assigns an IP address to the interface
security-level “number 0 to 100” : Assigns a security level to the interface
no shutdown : By default all interfaces are shut down, so enable them.
Static and Default Routes ciscoasa(config)# route outside 0.0.0.0 0.0.0.0 100.1.1.1 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 inside 192.168.2.0 255.255.255.0 192.168.1.1 [Configure a static route via the “inside” interface. To reach network 192.168.2.0/24 go via gateway IP 192.168.1.1 ]
Network Address Translation (NAT) 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 internal LAN (192.168.1.0/24) 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 PAT for all (“any”) networks to access the Internet using the outside interface]
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 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 service tcp 80 80 [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]
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
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 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 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 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 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 [Create a service group having several ports. This group can be used in other configuration commands such as ACLs]
ciscoasa(config)# access-list OUTSIDE-IN extended permit tcp any object-group DMZ_SUBNETS object-group DMZ_SERVICES [Example of using object groups in ACLs]
# 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
LOGIN
enable pass again
CONFIGURE MODE
configure terminal
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
edit in editor, paste
configure terminal
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
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
save (commit)
write mem
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