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    Default Routing Engine Protocol Queue Assignments

    Table 1 lists (in alphabetical order) how Routing Engine-sourced traffic is mapped to output queues. The follow caveats apply to Table 1:

    • For all packets sent to queue 3 over a VLAN-tagged interface, the software sets the 802.1p bit to 110, except for VRRP packets, in which case the software sets the 802.1p bit to 111.
    • For IPv4 and IPv6 packets, the software copies the IP type-of-service (ToS) value into the 802.1p field independently of which queue the packets are sent out.
    • For MPLS packets, the software copies the EXP bits into the 802.1p field.

      Table 1: Routing Engine Protocol Queue Assignments

      Routing Engine Protocol

      Queue Assignment

      Adaptive Services PIC

      TCP tickle (keepalive packets for idle session generated with stateful firewall to probe idle TCP sessions) are sent from queue 0.

      Bidirectional Forwarding Detection (BFD) Protocol

      Queue 3

      Border Gateway Protocol (BGP)

      Queue 0

      BGP TCP Retransmission

      Queue 3

      Cisco High-Level Data Link Control (HDLC)

      Queue 3

      Distance Vector Multicast Routing Protocol (DVMRP)

      Queue 3

      Frame Relay Local Management Interface (LMI)

      Queue 3

      Frame Relay Asynchronization permanent virtual circuit (PVC)/data link connection identifier (DLCI) status messages

      Queue 3

      FTP

      Queue 0

      Intermediate System-to-Intermediate System (IS-IS) Open Systems Interconnection (OSI)

      Queue 3

      Internet Group Management Protocol (IGMP) query

      Queue 3

      IGMP Report

      Queue 0

      IP version 6 (IPv6) Neighbor Solicitation

      Queue 3

      IPv6 Neighbor Advertisement

      Queue 3

      IPv6 Router Advertisement

      Queue 0

      Label Distribution Protocol (LDP) User Datagram Protocol (UDP) hello

      Queue 3

      LDP keepalive and Session data

      Queue 0

      LDP TCP Retransmission

      Queue 3

      Link Aggregation Control Protocol (LACP)

      Queue 3

      Link Services (LS) PIC

      If link fragmentation and interleaving (LFI) is enabled, all routing protocol packets larger than 128 bytes are transmitted from queue 0. This ensures that VoIP traffic is not affected. Fragmentation is supported on queue 0 only.

      Multicast listener discovery (MLD)

      Queue 0

      Multicast Source Discovery Protocol (MSDP)

      Queue 0

      MSDP TCP Retransmission

      Queue 3

      Multilink Frame Relay Link Integrity Protocol (LIP)

      Queue 3

      Open Shortest Path First (OSPF) protocol data unit (PDU)

      Queue 3

      Protocol Independent Multicast (PIM)

      Queue 3

      Real-time performance monitoring (RPM) probe packets

      Queue 3

      Resource Reservation Protocol (RSVP)

      Queue 3

      Routing Information Protocol (RIP)

      Queue 3

      Simple Network Management Protocol (SNMP)

      Queue 0

      SSH

      Queue 0

      Telnet

      Queue 0

      Virtual Router Redundancy Protocol (VRRP)

      Queue 3

      xnm-clear-text

      Queue 0

      xnm-ssl

      Queue 0

    Modified: 2017-04-14