Skip to content

Latest commit

 

History

History
198 lines (148 loc) · 5.99 KB

routing.md

File metadata and controls

198 lines (148 loc) · 5.99 KB
Raw

Common Routing Protocol Parameters

Most routing protocol modules support the following parameters:

(routing_router_id)=

Router ID

Router ID is configured with router_id node parameter (applies to all routing protocols) or with protocol.router_id node parameter (applies to the selected routing protocol). Router ID can be configured as an IPv4 address or as an integer.

The default router_id is taken from the IPv4 address of the loopback interface or the router_id address pool if there's no usable IPv4 address on the loopback interface.

Example:

modules: [ ospf, bgp ]

nodes:
  r1:
    router_id: 10.0.0.1
  r2:
    ospf.router_id: 10.0.0.2
    bgp.router_id: 10.0.1.2
  r3:
  • Router ID for R1 is configured for the whole device and used for OSPFv2/OSPFv3 and BGP
  • OSPFv2/OSPFv3 router ID for R2 is 10.0.0.2. BGP router ID for R2 is 10.0.1.2
  • Node ID for R3 is 3 (the third node in the nodes dictionary). The router ID for R3 is taken from the loopback interface (10.0.0.3 unless you changed the loopback address pool) or from the router_id address pool (10.0.0.3).

(routing_af)=

Address Families

Configuration modules for all IGP routing protocols that support multiple address families (IS-IS, EIGRP) or multiple protocol instances (OSPFv2, OSPFv3) support protocol.af global- or node-level module parameter. The af parameter can be a list- or a dictionary of address families.

The default value of the af parameter is set based on address families configured on loopback- or physical interfaces -- an address family is enabled within an IGP configuration on a device if at least one interface on that device has an IP address from that address family.

Example:

module: [ isis,ospf ]
isis.af.ipv6: True

nodes:
  r1:
    isis.af: [ ipv4, ipv6 ]
  r2:
    isis.af.ipv4: True
  r3:
    isis.af:
      ipv4: True
      ipv6: False
  r4:
    isis.af:
  r5:
  • IS-IS address families are enabled based on configured isis.af parameters
  • ospf.af parameter is not set -- OSPFv2 or OSPFv3 are enabled based on address families used on individual nodes

The following IS-IS address families are configured on individual routers:

  • R1: IPv4 and IPv6. The configured list of address families overrides the topology defaults
  • R2: IPv4 and IPv6. Node- and global parameters are dictionaries and can be merged.
  • R3: IPv4 only. The isis.af parameter is fully specified within the node data and explicitly disables IPv6 AF.
  • R4: The isis.af parameter is set to an empty value and is, therefore, calculated from the address families.
  • R5: IPv6 only (global default)

(routing_passive)=

Passive Interfaces

An interface is configured as a passive interface (when supported by the routing protocol implementation) if:

  • protocol.passive parameter is set to True on a link or interface.
  • The link type is set to stub (a single device is attached to the link)
  • The link role is set to passive
  • A single router or routing protocol daemon is attached to the link.

This parameter applies to IGP protocols.

Example:

module: [ ospf ]

nodes: [ r1, r2 ]

links:
- r1:
  r2:
- r1:
- r1:
  r2:
  role: passive
- r1:
  r2:
    ospf.passive: True
- r1:
  r2:
    ospf.passive: False
  role: passive
  • The first link is a transit link
  • The second link is a stub link (single node attached to the link) ⇨ The corresponding interface on R1 is passive
  • The third link has a passive role ⇨ passive interfaces on R1 and R2
  • The fourth link is a transit link, but the ospf.passive value is set on R2 interface ⇨ regular interface on R1, passive interface on R2
  • The last link has passive role, but the ospf.passive value is set to False on R2 interface ⇨ passive interface on R1, regular interface on R2.

(routing_external)=

External Interfaces

Links with role: external are not included in the IGP routing processes. The external role can be set with a link parameter or by the BGP module.

BGP module sets link role specified in defaults.bgp.ebgp_role on links connecting devices with different AS numbers. The system default value of that parameter is external, excluding inter-AS links from the IGP processes.

If you want to include external subnets into your IGP (and disable BGP next_hop_self processing), set defaults.bgp.ebgp_role to passive.

(routing_disable)=

Disabling a Routing Protocol on a Link/Interface

IGP protocols are usually configured on all internal interfaces (see for more details). You can disable an IGP protocol on a link or an individual interface with the protocol: False attribute, for example:

module: [ ospf ]

nodes:
  r1:
  r2:

links:
- r1:
  r2:
  ospf: False       # Disable OSPF on R1 and R2 interfaces
- r1:
    ospf: False     # Disable OSPF on R1 interface
  r2:               # OSPF is still enabled on R2 interface

You can also disable EBGP sessions on a link or an individual interface with the bgp: False attribute, for example:

module: [ bgp ]

defaults.device: iosv

nodes:
  r1:
    bgp.as: 65000
  r2:
    bgp.as: 65101

links:
- r1:
  r2:
  name: Regular EBGP
- r1:
  r2:
  bgp: False
  name: No EBGP session

You cannot influence IBGP sessions with interface- or link attributes; you must use advanced BGP node parameters.

(routing_disable_vrf)=

Disabling a Routing Protocol in VRF

You can disable a VRF instance of OSPF or BGP with ospf: False or bgp: False VRF parameter.

In the following example, OSPF will be configured in o_1 but not in o_2:

module: [ ospf, vrf ]

defaults.device: eos

vrfs:
  o_1:
  o_2:
    ospf: False

nodes:
  r1:
  r2:

links:
- r1:
  r2:
  vrf: o_1            # VRF OSPF is active between r1 and r2
- r1:
  r2:
  vrf: o_2            # No OSPF instance in o_2