confgraph

Cisco IOS-XR Parser Support Documentation

Overview

The IOS-XR parser (confgraph.parsers.iosxr_parser.IOSXRParser) parses Cisco IOS-XR device configurations. It inherits from IOSParser and overrides methods extensively where IOS-XR syntax diverges from IOS, including VRFs, interfaces, BGP, OSPF, ACLs, static routes, multicast, and all policy constructs.

Class: confgraph.parsers.iosxr_parser.IOSXRParser Inherits from: IOSParser CiscoConfParse syntax: iosxr OSType: OSType.IOS_XR (“ios_xr”)

Key Syntax Differences from IOS

Feature	IOS	IOS-XR
VRF definition	`vrf definition NAME`	`vrf NAME` (no keyword)
VRF route-targets	inline children	multi-line under `import/export route-target` stanzas
Interface VRF	`vrf forwarding NAME`	`vrf NAME` (no keyword)
IP address	`ip address X MASK`	`ipv4 address X MASK`
Interface ACL	`ip access-group NAME in\\|out`	`ipv4 access-group NAME ingress\\|egress`
ACL definition	`ip access-list standard\\|extended NAME`	`ipv4 access-list NAME` / `ipv6 access-list NAME`
Static routes	`ip route PREFIX MASK NEXTHOP`	`router static` block with nested `address-family` and optional `vrf` sub-blocks
BGP neighbor syntax	`neighbor X remote-as Y` (flat)	`neighbor X\n remote-as Y` (block-style)
BGP peer templates	`neighbor X peer-group NAME`	`neighbor-group NAME` / `use neighbor-group NAME`
BGP neighbor policies	flat AF block per neighbor	`route-policy NAME in/out` inside neighbor’s `address-family` sub-block
VRF BGP	`address-family ipv4 vrf NAME`	`vrf NAME` block under router bgp
Route-maps	`route-map NAME permit N`	`route-policy NAME` … `end-policy`
Prefix-lists	`ip prefix-list NAME seq N`	`prefix-set NAME` … `end-set` (comma-separated)
AS-path lists	`ip as-path access-list NAME`	`as-path-set NAME` … `end-set`
Community lists	`ip community-list`	`community-set NAME` … `end-set`
Extended communities	`ip extcommunity-list`	`extcommunity-set rt NAME` … `end-set`
OSPF interface membership	`ip ospf PROC area AREA` on interface	nested under `area N` → `interface NAME` in OSPF block
Multicast RP / SSM	flat `ip pim rp-address` / `ip pim ssm`	`router pim` with nested `address-family ipv4` block; separate `multicast-routing` block

Configuration Syntax Support

1. VRF Configuration

Syntax:

vrf <name>
  description <text>
  address-family ipv4 unicast
    import route-target
      <rt-value>
    export route-target
      <rt-value>
    import route-policy <name>
    export route-policy <name>

IOS-XR-Specific Differences:

VRF defined with vrf NAME (no definition keyword)
Route-targets listed under import route-target / export route-target stanzas as children
Import/export policies use route-policy instead of route-map

Supported Attributes:

VRF name
Route distinguisher (RD)
Route-target import/export (nested stanza format)
Import/export route-policies

Parsing Status: ✅ Overridden — parse_vrfs() handles vrf NAME with nested import/export route-target blocks and import/export route-policy

2. Interface Configuration

Syntax:

interface <type><number>
  description <text>
  vrf <vrf-name>
  ipv4 address <address> <mask>
  ipv6 address <address>/<prefix-length>
  ipv4 access-group <acl-name> ingress
  ipv4 access-group <acl-name> egress
  shutdown

IOS-XR-Specific Differences:

VRF: vrf NAME (no forwarding keyword)
IP address: ipv4 address X MASK instead of ip address X MASK
Interface ACL: ipv4 access-group NAME ingress|egress instead of ip access-group NAME in|out
OSPF interface membership is declared inside the OSPF block (not on the interface)

Supported Attributes:

All standard interface attributes (name, description, shutdown)
IPv4/IPv6 addresses
VRF membership
ACL in/out (acl_in, acl_out populated from ipv4 access-group)

Parsing Status: ✅ Overridden — parse_interfaces() handles ipv4 address X MASK, vrf NAME, and ipv4 access-group NAME ingress|egress

3. BGP Configuration

Syntax:

router bgp <asn>
  bgp router-id <router-id>
  neighbor-group <name>
    remote-as <asn>
    update-source <interface>
  neighbor <ip>
    remote-as <asn>
    description <text>
    use neighbor-group <name>
    address-family ipv4 unicast
      route-policy <name> in
      route-policy <name> out
  address-family ipv4 unicast
    network <prefix>/<length>
  vrf <vrf-name>
    rd <rd-value>
    neighbor <ip>
      remote-as <asn>
      address-family ipv4 unicast
        route-policy <name> in
        route-policy <name> out

IOS-XR-Specific Differences:

Neighbor definitions use block syntax (neighbor X\n remote-as Y) rather than flat neighbor X remote-as Y
Peer templates use neighbor-group NAME / use neighbor-group NAME
Route-policy assignments are inside each neighbor’s address-family sub-block
VRF BGP as vrf NAME block under router bgp

Supported Attributes:

All standard BGP attributes
Block-style neighbor parsing with per-neighbor AF policies
Neighbor-groups (equivalent to IOS peer-groups)
VRF BGP instances with route-policy in/out

Parsing Status:

✅ Overridden — _parse_bgp_neighbors() handles block-style neighbor syntax
✅ Overridden — _apply_bgp_af_neighbor_policies() reads route-policy NAME in/out from per-neighbor AF sub-blocks
✅ Overridden — _parse_bgp_peer_groups() handles neighbor-group NAME blocks
✅ Overridden — _parse_bgp_vrf_instances() handles vrf NAME blocks with block-style VRF neighbors

4. OSPF Configuration

Syntax:

router ospf <process-id>
  router-id <router-id>
  log adjacency changes detail
  redistribute bgp <asn> metric <m> metric-type <t> route-policy <name>
  area <area-id>
    interface <intf-name>
      cost <cost>
      network point-to-point
      passive enable

IOS-XR-Specific Differences:

Interface membership is declared inside the OSPF block under area N → interface NAME stanzas
Passive interfaces are indicated by passive enable inside the interface stanza
Redistribution uses route-policy instead of route-map

Supported Attributes:

Process ID, router-id
Areas with nested interface assignments
Area types (stub, NSSA)
Passive interfaces (detected via passive enable within interface stanza)
Redistribution with route-policy

Parsing Status: ✅ Overridden — parse_ospf() and _parse_ospf_areas_iosxr() handle area-nested interface blocks and passive enable detection

5. Route-Maps (Route-Policies)

Syntax:

route-policy <name>
  if destination in <prefix-set> then
    set local-preference <value>
    set community <community> additive
  else
    drop
  endif
end-policy

IOS-XR-Specific Differences:

route-policy NAME / end-policy blocks replace IOS route-map sequences
Policy body uses an if/then/else language
set and pass/drop statements replace IOS set/permit/deny

Supported Attributes:

Policy name
Best-effort match extraction: if destination in PREFIX_SET → match clause
Best-effort set extraction: set commands → set clauses
Full policy body preserved in raw_lines

Note: IOS-XR route-policy bodies use an if/then/else language. The parser performs best-effort extraction sufficient for dependency graph analysis (identifying referenced prefix-sets and communities). The full policy body is preserved in raw_lines.

Parsing Status: ✅ Overridden — parse_route_maps() maps route-policy/end-policy blocks to RouteMapConfig

6. Prefix-Lists (Prefix-Sets)

Syntax:

prefix-set <name>
  10.0.0.0/8 le 32,
  192.168.0.0/16 ge 24 le 32,
  0.0.0.0/0
end-set

IOS-XR-Specific Differences:

prefix-set NAME / end-set blocks replace IOS ip prefix-list
Entries are comma-separated within the block
No per-entry sequence numbers or permit/deny keywords; the set is referenced by route-policies

Supported Attributes:

Set name
Prefix entries (network/length, ge/le modifiers)

Parsing Status: ✅ Overridden — parse_prefix_lists() maps prefix-set/end-set comma-separated entries to PrefixListConfig

7. AS-Path Lists (AS-Path Sets)

Syntax:

as-path-set <name>
  ios-regex '^65000_',
  ios-regex '_65001_'
end-set

IOS-XR-Specific Differences:

as-path-set NAME / end-set blocks replace IOS ip as-path access-list
Entries use ios-regex keyword

Parsing Status: ✅ Overridden — parse_as_path_lists() maps as-path-set/end-set to ASPathListConfig

8. Community Lists (Community-Sets and Extcommunity-Sets)

Syntax:

community-set <name>
  65000:100,
  65000:200
end-set

extcommunity-set rt <name>
  65000:1,
  65000:2
end-set

IOS-XR-Specific Differences:

community-set NAME / end-set blocks replace IOS ip community-list
extcommunity-set rt NAME / end-set blocks capture extended communities used as route-targets; stored as CommunityListConfig with list_type="extended"

Parsing Status: ✅ Overridden — parse_community_lists() maps both community-set/end-set and extcommunity-set rt/end-set to CommunityListConfig

9. ACLs

Syntax:

ipv4 access-list INBOUND-ISP1
 10 deny ipv4 any host 10.0.0.1
 20 permit ipv4 any any
!
ipv6 access-list INBOUND-V6
 10 permit ipv6 any any

IOS-XR-Specific Differences:

ipv4 access-list NAME and ipv6 access-list NAME replace IOS ip access-list standard|extended NAME
Both IPv4 and IPv6 ACL blocks are parsed

Parsing Status: ✅ Overridden — parse_acls() handles ipv4 access-list and ipv6 access-list blocks

10. Static Routes

Syntax:

router static
 address-family ipv4 unicast
  0.0.0.0/0 192.168.1.1
  192.0.2.0/24 Null0 254
 !
 vrf CUST-A
  address-family ipv4 unicast
   0.0.0.0/0 10.0.0.2

IOS-XR-Specific Differences:

All static routes are defined inside a router static block
Routes are under address-family ipv4 unicast sub-blocks
Per-VRF routes use a nested vrf NAME sub-block within router static

Parsing Status: ✅ Overridden — parse_static_routes() handles the router static block with nested address-family and vrf sub-blocks

11. Multicast

Syntax:

router pim
 address-family ipv4
  rp-address 10.0.0.1
  ssm range RFC1918
!
multicast-routing
 address-family ipv4

IOS-XR-Specific Differences:

RP addresses and SSM config are nested under router pim → address-family ipv4 blocks
multicast-routing is a separate top-level block (IOS uses flat ip pim statements)

Parsing Status: ✅ Overridden — parse_multicast() handles router pim with nested address-family ipv4 blocks and the separate multicast-routing block

12. Extended Protocol Support (Inherited from IOSParser)

The following protocols use IOS-identical syntax in IOS-XR:

Protocol	Parsing Status
NTP	✅ Inherited from IOSParser
SNMP	✅ Inherited from IOSParser
Syslog	✅ Inherited from IOSParser
Banners	✅ Inherited from IOSParser
Line configs (con/vty)	✅ Inherited from IOSParser
QoS (class-map/policy-map)	✅ Inherited from IOSParser
BFD	✅ Inherited from IOSParser
IP SLA	✅ Inherited from IOSParser
EEM Applets	✅ Inherited from IOSParser
Object Tracking	✅ Inherited from IOSParser

See IOS_PARSER_SUPPORT.md for full syntax and attribute details.

Overridden Methods Summary

Method	Reason for Override
`parse_vrfs()`	Handles `vrf NAME` with nested `import/export route-target` blocks and `import/export route-policy`
`_extract_interface_vrf()`	Handles `vrf NAME` (no `forwarding` keyword)
`parse_interfaces()`	Handles `ipv4 address X MASK`, `vrf NAME`, and `ipv4 access-group NAME ingress\\|egress`
`parse_acls()`	Handles `ipv4 access-list NAME` and `ipv6 access-list NAME` blocks
`parse_static_routes()`	Handles `router static` block with nested `address-family` and `vrf` sub-blocks
`_parse_bgp_neighbors()`	Handles block-style neighbor syntax (`neighbor X\n remote-as Y`)
`_apply_bgp_af_neighbor_policies()`	Reads `route-policy NAME in/out` from per-neighbor `address-family` sub-blocks
`_parse_bgp_peer_groups()`	Handles `neighbor-group NAME` blocks
`_parse_bgp_vrf_instances()`	Handles `vrf NAME` blocks under router bgp with block-style VRF neighbor parsing
`parse_ospf()`	Consumes passive interface list from `_parse_ospf_areas_iosxr()`
`_parse_ospf_areas_iosxr()`	Handles area-nested interface blocks; detects `passive enable`
`parse_route_maps()`	Maps `route-policy`/`end-policy` blocks to `RouteMapConfig`
`parse_prefix_lists()`	Maps `prefix-set`/`end-set` comma-separated entries to `PrefixListConfig`
`parse_as_path_lists()`	Maps `as-path-set`/`end-set` to `ASPathListConfig`
`parse_community_lists()`	Maps `community-set`/`end-set` and `extcommunity-set rt`/`end-set` to `CommunityListConfig`
`parse_multicast()`	Handles `router pim` nested AF blocks and separate `multicast-routing` block

Parser Limitations

Route-policy full semantics — Complex if/then/else logic is best-effort; only destination in PREFIX_SET and set commands are extracted
IPv6 routing — Limited IPv6 routing protocol coverage
IOS-XR-specific features — Segment Routing, MPLS-TE, L2VPN not parsed

Testing and Validation

Sample Configuration: samples/iosxr_test.cfg

Validated output (confgraph info samples/iosxr_test.cfg --os iosxr):

Hostname : XR-CORE-01
OS       : ios_xr
Interfaces         2
VRFs               1
BGP instances      2
OSPF instances     1
Route-maps         4
Prefix-lists       2
ACLs               3
Community-lists    2
AS-path-lists      1
Static routes      3
SNMP               1

Quick Reference

from confgraph.parsers.iosxr_parser import IOSXRParser
from confgraph.models.base import OSType

parser = IOSXRParser(config_text)
parsed = parser.parse()
# os_type = OSType.IOS_XR  # "ios_xr"

confgraph info samples/iosxr_test.cfg --os iosxr

Last Updated: 2026-04-13 Parser Version: 1.2.0

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