Skip to main content

Cisco Secure ACS 5.3 and GNS3


In a previous post I showed how I installed ACS in VBox. The reason I wanted it in VBox was so I could add it to GNS3 topology as a host. GNS uses first NIC in of a VM as a “management” NIC and adds a second NIC for linking within the topology.  ACS supports only single NIC (even the hardware appliance that comes with 4 NICs, has 3 of them disabled). “Runtime”  is the process that listens to and processes TACACS and RADIUS requests. It gets “bound” to the IP addresses configured during the initial setup. When ACS is added to GNS and second NIC installed and configured, the "runtime" still listens only on the first NICs IP address. Configuring the second NIC, disabling the first one and restarting ACS application results in "runtime" not starting at all.

To get around that, I needed to do the following at the ACS’s console once ACS was added to GNS as a VBox host:

1.         Configure second NIC with the same IP address as the first one

# configure terminal
# interface gigabitEthernet 1
# ip address 10.0.0.5 255.255.255.0 (or whatever address you used)
don't restart the services
#exit
#copy running-config startup-config

2.       Restart the VM and login to ACS

# configure terminal
# interface gigabitEthernet 0
# shutdown
don't restart the services
# end

3.       Restart ACS app (not the VM just the application)

# acs stop
# acs start

It takes a few minutes to stop and restart

4.       Confirm all ACS processes are started

# show application status acs

5.       Confirm ACS is listening on runtime ports (TCP 49 for TACACS)

# show ports

When you do “show interfaces”, ACS displays real interface names (eth0 and eth1) however to configure them you need to use “gigabitEthernet”.  

You could also try editing the startup-config file by booting to a Live Linux CD and editing the file using VI or some other text editor. The config file is stored in /_storedconfig partition. 

Comments

Popular posts from this blog

x.509 Certificates - Critical vs non-critical extensions

Extensions are used to associate additional information with the user or the key.  Each certificate extension has three attributes - extnID, critical, extnValue extnID - Extension ID - an OID that specifies the format and definitions of the extension critical - Critical flag - Boolean value extnValue - Extension value  Criticality flag specifies whether the information in an extension is important. If an application doesn't recognize the extension marked as critical, the certificate cannot be accepted. If an extension is not marked as critical (critical value False) it can be ignored by an application. In Windows, critical extensions are marked with a yellow exclamation mark,  View certificate extensions using OpenSSL: # openssl x509 -inform pem -in cert.pem -text -noout (output abbreviated)         X509v3 extensions:             X509v3 Key Usage: critical                 Digital Signature, Key Encipherment             X509v3 Subject Key Identifier

Count number of lines - 'findstr'

How do I count number of lines in a command output? findstr /r/n "^" | find /c ":" Above commands will display number of lines output by whatever command (well, nearly whatever) you specify in the front.  For example:  C:\>ping localhost | findstr /r/n "^" | find /c ":" FINDSTR: // ignored 12 This comes handy if you want to find out how many OUs you have in Active Directory: dsquery ou  -limit 0 | findstr /r/n "^" | find /c ":" How many user accounts there are: dsquery user -limit 0 | findstr /r/n "^" | find /c ":" Computers: dsquery computer -limit | findstr /r/n "^" | find /c ":"

Cisco ASA Certificate Revocation Checking

ASA supports status verification using CRLs and OCSP. CRL can be retrieved using HTTP, LDAP or SCEP. Revocation checking using CRL: Over HTTP: ciscoasa(config)# crypto ca trustpoint ASDM_TrustPoint2 ciscoasa(config-ca-trustpoint)# revocation-check crl ciscoasa(config-ca-crl)# protocol http By default ASA will use address listed in CDP extension of the certificate that is being validated.  To override default behaviour we need to add the following in the CRL configuration context. ciscoasa(config-ca-crl)# policy static ciscoasa(config-ca-crl)# url 1 http://cdpurl.kp.local/crl.crl Over LDAP: Certificate I'm using for this lab, doesn't have LDAP address in its CDP extension. Therefore I'm using "policy static"  to specify LDAP URL where CRL can be retrieved.  ciscoasa(config)# crypto ca trustpoint ASDM_TrustPoint2 ciscoasa(config-ca-trustpoint)# revocation-check crl ciscoasa(config-ca-trustpoint)# crl configure ciscoasa