| Internet-Draft | IfStackTable for P2P interface | June 2021 |
| Liu, et al. | Expires 19 December 2021 | [Page] |
The point-to-point circuit type is one of the mainly used circuit types in link state routing protocol. It is important to identify the correct circuit type when forming adjacencies, flooding link state database packets, and monitor the link state. This document defines point-to-point interface type and relevant stack tables to provide benefit for operation, maintenance and statistics.¶
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Point-to-point is the predominant circuit type used by link state routing protocols such as IS-IS [RFC1195] and OSPF [RFC2328] [RFC5340]. Compare with broadcast interface, point-to-point interface is used differently when establish neighbor adjacencies, flood link state information, representing the topology, etc.¶
To simplify configuration and operation, it is helpful To represent the fact that an interface is to be considered a point-to-point interface explicitly in the interface stack. This enables, for example, routing protocols to automatically use the correct operating mode without further configuration.¶
So it is necessary to abstract P2P as special sub-type type and define relevant interface stack table. And if no entry saying p2pOverLan layer over ethernet, the management will suffer since lose the ability to get to the Ethernet-specific management properties (Ethernet MIB or YANG model) via many tools.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].¶
As defined in [RFC8343], if the device implements the IF-MIB [RFC2863], each entry in the "/interfaces/interface" list in the operational state is typically mapped to one ifEntry.¶
So P2P as sub-interface type should also fully map to one ifEntry, meanwhile define the "higher-layer-if" and "lower-layer-if" in the YANG corresponding to "ifStackTable" in IF-MIB to setup a complete interface stack table, then the P2P interface type can borrow all existing items in interfaces YANG and IF-MIB to take the full advantages from operation, statistic, etc.¶
The "higher-layer-if" should be a network layer interface type, and the lower-layer-if should be a data link layer interface type.¶
+--------------------------------------+----------------------------+ | YANG data node in | IF-MIB object | | /interfaces/interface | | +--------------------------------------+----------------------------+ | name | ifName | | type | ifType | | description | ifAlias | | admin-status | ifAdminStatus | | oper-status | ifOperStatus | | last-change | ifLastChange | | if-index | ifIndex | | link-up-down-trap-enable | ifLinkUpDownTrapEnable | | phys-address | ifPhysAddress | | higher-layer-if and lower-layer-if | ifStackTable | | speed | ifSpeed and ifHighSpeed | | discontinuity-time | ifCounterDiscontinuityTime | | in-octets | ifHCInOctets | | in-unicast-pkts | ifHCInUcastPkts | | in-broadcast-pkts | ifHCInBroadcastPkts | | in-multicast-pkts | ifHCInMulticastPkts | | in-discards | ifInDiscards | | in-errors | ifInErrors | | in-unknown-protos | ifInUnknownProtos | | out-octets | ifHCOutOctets | | out-unicast-pkts | ifHCOutUcastPkts | | out-broadcast-pkts | ifHCOutBroadcastPkts | | out-multicast-pkts | ifHCOutMulticastPkts | | out-discards | ifOutDiscards | | out-errors | ifOutErrors | +--------------------------------------+----------------------------+
YANG Data Nodes and Related IF-MIB Objects¶
P2P interface type is a kind of point-to-point circuit type. P2P interface higher layer should be network layer "ipForward" (defined in IANA) to run routing protocol, P2P interface lower layer is link data layer "ethernetCsmacd" (defined in IANA).¶
P2P interface type ifStackTable should be defined as the following example:¶
<interface>
<name>isis_int</name>
<type>ianaift:ipForward</type>
</interface>
<interface>
<name>eth1</name>
<type>ianaift:ethernetCsmacd</type>
</interface>
<interface>
<name>p2p</name>
<type>ianaift:p2pOverLan</type>
<higher-layer-if>isis_int</higher-layer-if>
<lower-layer-if>eth1</lower-layer-if>
<enabled>false</enabled>
<admin-status>down</admin-status>
<oper-status>down</oper-status>
<statistics>
<discontinuity-time>
2021-04-01T03:00:00+00:00
</discontinuity-time>
<!-- counters now shown here -->
</statistics>
</interface>
The interface stack table specified in this document is read-only. Read operation to this table without complete protection shouldn't have a negative effect on network operations.¶
The interface stack table defines to be accessed via network management protocols such as NETCONF [RFC6241], RESTCONF [RFC8040]. The NETCONF is over on layer secure transport, and the mandatory secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446].¶
IANA need to update the "Interface Types(ifType)" registry (available at https://www.iana.org/assignments/smi-numbers/smi-numbers.xhtml#smi-numbers-5) with the following status types:¶
+=========+==================+=======================================+ | Decimal | Name | Description | +=========+==================+=======================================+ | 303 | p2pOverLan | Point to Point over LAN interface | +---------+------------------+---------------------------------------+
IANA need to update the "IANAifType-MIB" registry (available at https://www.iana.org/assignments/ianaiftype-mib/ianaiftype-mib.xhtml) with the following status types:¶
+=========+==================+=======================================+ | Value | Name | Description | +=========+==================+=======================================+ | 303 | p2pOverLan | Point to Point over LAN interface | +---------+------------------+---------------------------------------+
IANA need to update the "iana-if-type YANG Module" registry (available at https://www.iana.org/assignments/iana-if-type/iana-if-type.xhtml) with the following status types:¶
identity p2pOverLan {
base iana-interface-type;
description
"Point to Point over LAN interface.";
}