Parse Cisco ASA and FTD running configurations into the shared firewall schema. Use when input contains show running-config, access-list, access-group, object network, object-group, nameif, security-level, NAT, interfaces, or failover, including audit, conversion, diff, summary, and explanation tasks.
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Parse Cisco ASA and FTD running configurations into the shared firewall schema. Use when input contains show running-config, access-list, access-group, object network, object-group, nameif, security-level, NAT, interfaces, or failover, including audit, conversion, diff, summary, and explanation tasks.
Use this skill to parse Cisco ASA and ASA-style FTD running configurations into the shared vendor-neutral firewall intermediate schema. It focuses on line-oriented show running-config text with parent commands and indented subcommands, including interfaces/nameifs, ACLs/access-groups, network and service objects, object-groups, NAT, routes, VPN, failover, and system settings.
Treat FMC-managed FTD exports and API data as adjacent but not identical inputs: parse what is present, preserve unresolved or unsupported structures in residual_raw, and call out assumptions rather than inventing missing policy context.
Scope and routing
Use only for Cisco ASA or FTD syntax. Hand off FortiOS config/edit/next/end blocks to parsing-fortinet-configs, PAN-OS XML or set deviceconfig to parsing-palo-configs, and Junos hierarchy or set security to parsing-srx-configs. Verify production-bound results against current device documentation and output. Downstream consumers are the audit, conversion, and diff skills.
Input Format
Cisco ASA configs are line-oriented with indented sub-commands:
Named interfaces use nameif (e.g., inside, outside, dmz)
security-level (0-100) determines trust level
Building Command Blocks
Group indented lines under their parent top-level command — see references/parsing-patterns.md "Building Command Blocks" for the algorithm and worked example.
Extraction Pipeline
1. Interfaces
Source: interface <hardware-id> blocks
Extract from sub-commands:
nameif <name> — the logical name used everywhere else
security-level <0-100> — trust level
ip address <ip> <mask> — IP and subnet mask
vlan <id> — VLAN assignment
shutdown — interface is administratively down
description <text>
bridge-group <id> — transparent mode bridge group membership
Interface types: detect Port-channel* as lag, Tunnel* as tunnel, Loopback* as loopback, Management* as management. Sub-interfaces contain . in name (e.g., GigabitEthernet0/0.100) — derive parent from name before the dot.
2. Zones (Derived from Interfaces)
ASA doesn't have explicit zones. Derive them from nameif values:
Each unique nameif becomes a zone
security-level values are parser-internal inference metadata used to determine relative trust ordering between zones (higher = more trusted). This is NOT emitted as a security_level or trust_level field in the intermediate schema — use it only to guide ordering or warn when ACLs are absent.
Associate the interface with its zone
3. Network Objects
Source: object network <name> blocks
Types from sub-commands:
host <ip> → type: "host", value: ip + "/32" (or "/128" for IPv6)
subnet <ip> <mask> → type: "subnet", value: ip + "/cidr" (convert mask to CIDR)
range <start> <end> → type: "range", value: "start-end"
fqdn v4 <domain> or fqdn v6 <domain> → type: "fqdn"
Note: bare fqdn <domain> (without v4/v6 qualifier) is also valid.
subnet <ipv6-prefix> → for IPv6 subnets the value is already in CIDR form, no mask conversion needed.
Also extract: description, inline nat statement (for object/auto NAT).
4. Network Object Groups
Source: object-group network <name> blocks
Members from sub-commands:
network-object host <ip> → inline host
network-object <ip> <mask> → inline subnet
network-object object <name> → reference to named object
group-object <name> → nested group reference
5. Service Objects
Source: object service <name> blocks
Parse: service <protocol> [source <op> <port>] [destination <op> <port>]
Operators: eq, range, gt, lt, neq
6. Service Object Groups
Source: object-group service <name> [<protocol>] blocks
Members:
port-object eq <port> / port-object range <start> <end>
Parse source static|dynamic and optional destination static components.
The optional numeric token is a line number — the rule's position within its manual NAT section — NOT a section selector. Derive the section from rule form: Section 1 = manual/twice NAT without after-auto (evaluated before object/auto NAT); Section 2 = object/auto NAT (rules inside object network blocks); Section 3 = manual NAT with the after-auto keyword (evaluated after all auto NAT).
Note: route-map and prefix-list references are not converted (warn)
OSPF:router ospf <pid> block — extract:
router-id, auto-cost reference-bandwidth
network <ip> <wildcard> area <id> — match interfaces to areas via wildcard mask comparison
Area types: stub, nssa, with no-summary; area default-cost; area authentication
passive-interface default + no passive-interface <nameif> exceptions
redistribute (connected/static with metric/metric-type)
Interface-level: ip ospf cost, ip ospf priority, ip ospf hello-interval, ip ospf dead-interval, ip ospf network point-to-point, ip ospf authentication message-digest + key
Normalize area IDs to dotted-decimal (0 → 0.0.0.0)
OSPFv3:router ospfv3 block with address-family ipv6 unicast — similar structure to OSPFv2
13. Infrastructure
Hostname:hostname <name> and domain-name <domain> → system metadata
Version:asa version <X.Y> or firepower version <X.Y> → metadata.source_version
HA/Failover:failover presence + failover lan unit primary|secondary (capture unit role),
failover interface ip, failover link
Flag weak algorithms (DES/3DES, MD5, DH group ≤ 5)
Syslog:logging host <nameif> <ip>
DHCP Server:dhcpd address <start>-<end> <nameif> (pool range),
dhcpd dns <ip1> [<ip2>], dhcpd domain <domain>, dhcpd lease <seconds>,
dhcpd enable <nameif> (commit trigger — binds staged options to interface).
Derive network CIDR from the interface IP.
DHCP Relay:dhcprelay server <ip> <iface> + dhcprelay enable <nameif>
14. Application Mapping (L7 → Canonical)
ASA/FTD is a port-based platform — it does not have native L7 application awareness in ACLs.
However, when converting FROM ASA to an app-aware platform (PAN-OS, FortiGate), or comparing
configs, the parser should attempt to resolve well-known port/protocol combinations to canonical
application names.
Resolution from port-based services:
For each service object or inline port match, check if the protocol+port maps to a known application:
Protocol
Port(s)
Canonical App
Category
TCP
443
https
web
TCP
80
http
web
TCP
22
ssh
remote-access
TCP
3389
rdp
remote-access
UDP
53
dns
network-mgmt
TCP
25
smtp
email
TCP
465
smtps
email
TCP
993
imaps
email
TCP
143
imap
email
UDP
123
ntp
network-mgmt
UDP
161
snmp
network-mgmt
UDP
162
snmp-trap
network-mgmt
TCP
21
ftp
file-transfer
TCP
23
telnet
remote-access
TCP
389
ldap
auth
TCP
636
ldaps
auth
UDP
69
tftp
file-transfer
TCP
1433
mssql
database
TCP
3306
mysql
database
TCP
5432
postgresql
database
TCP
445
smb
file-transfer
UDP
500
ipsec
tunnel
UDP
4500
ipsec-nat-t
tunnel
TCP
5060
sip
voip
UDP
5060
sip
voip
ASA named port keywords: Map ASA port names to numbers before resolving — full table in references/parsing-patterns.md "Port Name Resolution". Caution: ASA literals predate IANA assignments (radius=1645, radius-acct=1646, kerberos=750) — do not "correct" them from prior knowledge; use the reference table.
On policy output: When a service match resolves to a known application, populate the policy's
apps array with { vendor_name: "tcp/443", canonical: "https", confidence: 1.0, category: "web" }.
The services array still keeps the port-based match. This enables downstream converters to use
the app-aware rule on platforms that support it.
Unresolvable services: Complex port ranges, non-standard ports, or protocol groups that don't
map to a single known application → keep as port-based services only, no apps entry.
15. Application Groups
ASA does not have application groups. However, when converting FROM an app-aware platform,
object-group service entries that resolve entirely to known applications should be flagged
as potential application_groups in the IR for downstream use.
16. Anonymous Objects
When inline addresses/services appear in ACLs or object groups without a named reference (e.g., host 10.0.1.10 directly in an ACL line), create anonymous objects with auto-generated names (e.g., anon-1-host, anon-2-net). This ensures every IR reference points to a named object.
17. Residual Config Capture
Capture unrecognized top-level commands verbatim. Categorize into: VPN/IPsec, AAA, QoS, PKI/Certificates, IPv6, Other. Store in residual_raw for manual review.
18. Transparent Mode
Detect: firewall transparent in config
When in transparent mode:
Interfaces are in bridge-groups instead of having IPs
bridge-group <id> on interfaces
BVI interfaces (interface BVI<id>) carry the management IP
Zones derived from nameifs still work the same way
19. Implicit Rules
The ASA implicit deny is scoped per bound ACL, not global: each ACL applied via access-group
ends with an implicit deny for that interface/direction only. Applying an ACL on one interface
does NOT disable security-level defaults for other interface pairs.
After building all policies from ACLs + access-groups, append:
Implicit: Default Deny — one per access-group binding — action: "deny",
src_zones: [<bound nameif>] for in direction (dst_zones for out; all any for
global), remaining fields any, _implicit: true
When every traffic-passing interface has a bound ACL (or a global access-group exists),
the per-binding denies may be collapsed into a single final any→any deny, _implicit: true
For interfaces with NO ACL bound: do not fabricate a deny — security-level defaults still
apply (higher-to-lower permitted, lower-to-higher denied). Add a metadata.warnings entry
("no ACL bound on — security-level high-to-low permit applies") and, if downstream
consumers need explicit rules, model the default permit as an _implicit: true allow policy
from that zone to lower-security zones
Implicit-rule name values (e.g. "default-deny", "Implicit: Default Deny") are free-form labels; consumers must match implicit rules on _implicit: true, never on the name.
Output Format
Present results in the intermediate schema format documented in references/intermediate-schema.md.
Note: schema sections not yet populated by this pipeline (e.g., security_profile_objects, routing_contexts) are emitted empty ([]/{}); any unhandled source constructs are captured in residual_raw rather than dropped.
Full intermediate-schema emission is optional for single live-device work. The complete JSON schema exists primarily for cross-vendor conversion and multi-config diffing. When interpreting or auditing a single live device pulled via SSH/API for an ops/audit task, it is fine to reason directly from the running config and skip full schema emission — extract the sections relevant to the question. Emit the full schema when the parse will feed firewall-config-conversion, firewall-config-diff, or another config for comparison.
Parser Quality Gates
Before returning a parse, run these common quality gates and include the results in the response:
Format and scope detection — report detected vendor, platform family, config format, version clues, virtual context names (VDOM/vsys/logical-system/routing-instance), and whether input appears complete or partial.
Schema conformance — emit the vendor-neutral JSON sections defined in references/intermediate-schema.md; use empty arrays/objects for absent sections rather than omitting expected top-level keys.
Object counts — summarize counts for zones, interfaces, address objects/groups, service/application objects/groups, policies, NAT rules, routes, VPNs, HA, admin users, and residual blocks.
Reference resolution — list unresolved object, service/application, zone/interface, profile, route, VPN, and NAT references with source rule/context where possible.
Ordering preservation — preserve security policy order, NAT order, route order when relevant, and inherited/pre/post/global ordering metadata with _rule_index or a vendor-specific context field.
State preservation — preserve disabled/inactive objects and rules, comments/descriptions, tags, schedules/time-ranges, negation flags, logging settings, and profile attachments.
Residual capture — put unsupported or ambiguous source lines/blocks into residual_raw with enough context for manual review. Do not silently drop unknown syntax.
Warnings and assumptions — populate metadata.warnings with parser limitations, partial-input assumptions, ambiguous conversions, and version-specific caveats.
Conversion readiness — if the user asks for migration/conversion, explicitly separate parsed facts from proposed target-platform design choices and call out non-isomorphic features.
A high-quality parse is not just valid JSON: it must make uncertainty visible. Prefer a complete parse with warnings and residuals over a clean-looking parse that hides unsupported constructs.
Analysis Checks
After extraction, run these checks and report findings:
Unused objects — network/service objects not referenced in any ACL
Shadowed ACL entries — rules that can never match due to earlier entries
Overly permissive — permit ip any any or broad rules
Missing logging — permit ACL entries without log keyword
Inactive entries — ACL entries with inactive flag
Duplicate objects — same value, different names
Empty groups — object-groups with no members
Unbound ACLs — access-lists without matching access-group (never applied)
Subnet mask validation — flag any non-standard subnet masks
references/fixture-expected-output.json — Expected high-level intermediate-schema output for the minimal fixture
Secret Handling
Never emit secrets raw. Tunnel-group pre-shared keys, username ... password hashes, BGP neighbor passwords, and SNMP community strings must be masked as "****" (or represented as a presence flag) with a metadata.warnings entry noting the secret was redacted — matching the shared-schema convention ("psk": "****").
Common Pitfalls
Do not treat IOS wildcard masks as ASA subnet masks; ASA object subnets use standard dotted masks.
Do not infer policy direction from ACL names alone; bind ACLs to interfaces with access-group.
Object NAT and manual/twice NAT order matters. Preserve NAT section/order metadata and flag ambiguous translations.
Security levels are not zones by themselves, but they help infer trust roles when no explicit design notes exist.
FTD/FMC-managed output may omit policy context available in FMC; preserve gaps as warnings instead of fabricating rules.
Verification Checklist
Input vendor/platform and config format were detected correctly
All major object counts are reported: zones, interfaces, addresses, services/applications, policies, NAT, routes, VPN, HA, and system settings
Output conforms to references/intermediate-schema.md
Disabled/inactive rules and objects are preserved with explicit state
Unresolved references, unsupported blocks, and parser assumptions are listed in metadata.warnings and/or residual_raw
Rule order and NAT order are preserved with _rule_index or equivalent ordering metadata
Cross-vendor conversion caveats are called out before suggesting target-platform config
No raw secrets in output — PSKs masked as "****", routing-protocol passwords/keys reduced to presence flags with warnings
