Удалось выяснить, что vpnc отрубается на моменте аутентификации в LDAP

>>>vpnc

[21] Session Start
[21] New request Session, context 0xc9744a30, reqType = Authentication
[21] Fiber started
[21] Failed: The username or password is blank
[21] Fiber exit Tx=0 bytes Rx=0 bytes, status=-3
[21] Session End

>>>Cisco Vpn Client

[22] Session Start
[22] New request Session, context 0xc9744a30, reqType = Authentication
[22] Fiber started
[22] Creating LDAP context with uri=ldap://172.30.0.250:389
[22] Connect to LDAP server: ldap://172.30.0.250:389, status = Successful
[22] supportedLDAPVersion: value = 3
[22] supportedLDAPVersion: value = 2
[22] LDAP server 172.30.0.250 is Active directory
[22] Binding as asa
[22] Performing Simple authentication for asa to 172.30.0.250
[22] LDAP Search:
        Base DN = [dc=mydomain, dc=local]
        Filter  = [sAMAccountName=myusername]
        Scope   = [SUBTREE]