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RED drop on Juniper due to RSVP Interoperability issue with Cisco.

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Article ID: KB15011 KB Last Updated: 21 Oct 2020Version: 1.0
Summary:
RED drop on Juniper due to RSVP Interoperability issue with Cisco.
Symptoms:
Limitation on Cisco:
To signal Penultimate Hop Popping (PHP), a Cisco egress router sends label 0 to the penultimate hop in the control plane, whereas a Juniper Networks egress router sends label 3 (implicit NULL).

If traffic rate increases beyond 25-30% approx. RED (Random Early Detection) drops are seen on the Juniper router due to Pause frames coming from Cisco.
Solution:
Agilent-----Cisco-3845----Att-M320----Att-640------Agilent
                        <----------Traffic flow------ Transmit Rate: 279.53MB/S
  • Cisco Loopback: 11.11.11.11
  • ATT-640 Loopback: 9.9.9.9
  • 1GE interface end to end.
  • Juniper is PHP router and Cisco is PE.

There are two possible solutions to stop RED drop on a Juniper router.

  1. Configure no-flow-control.

  2. Use mpls traffic-eng signalling advertise implicit-null on Cisco.

1. Configure no-flow-control

Juniper is receiving MAC pause frames from Cisco. Since Cisco router is not able to process packets due to high incoming traffic.

  • Before enabling no-flow control on interface between Juniper-Cisco
    show interfaces ge-6/1/0 extensive
    <...>
    MAC statistics:                      Receive         Transmit
        Total octets                    7698137040     814273350791
        Total packets                    120074767      12090571383
        Unicast packets                      30165      12090535886
        Broadcast packets                       24               58
        Multicast packets                120044578            35439
        CRC/Align errors                         0                0
        FIFO errors                              0                0
        MAC control frames               120025971                0
        MAC pause frames                 120025971                0
    

    MAC pause frames are increasing on the Juniper router.

  • By default flow control is enable on interface. Therefore Juniper is doing tail drop on the outgoing interface.
    Juniper@ATT-M320-Re0# run show interfaces queue ge-6/1/0  
    Physical interface: ge-6/1/0, Enabled, Physical link is Up
    Interface index: 202, SNMP ifIndex: 153
    Description: Connected to CISCO-3845 ge-0/0
    Forwarding classes: 16 supported, 4 in use
    Egress queues: 4 supported, 4 in use
    Queue: 0, Forwarding classes: best-effort
      Queued:
        Packets              :               9162921                538987 pps
        Bytes                :             531449418             250089968 bps
      Transmitted:
        Packets              :               8462011                497400 pps
        Bytes                :             490796638             230793600 bps
        Tail-dropped packets :                118476                  7097 pps
        RED-dropped packets  :                700441                 42160 pps
         Low, non-TCP        :                700441                 42160 pps
         Low, TCP            :                     0                     0 pps
         High, non-TCP       :                     0                     0 pps
         High, TCP           :                     0                     0 pps
        RED-dropped bytes    :              44828224              21585920 bps
         Low, non-TCP        :              44828224              21585920 bps
         Low, TCP            :                     0                     0 bps
         High, non-TCP       :                     0                     0 bps
         High, TCP           :                     0                     0 bps
  • Interface Stats on Cisco Side
    CISCO-3845(config)#do sh int g0/0
    GigabitEthernet0/0 is up, line protocol is up 
    Hardware is BCM1125 Internal MAC, address is 0016.c8e6.9fb0 (bia 0016.c8e6.9fb0)
    Description: "**Connection to Node-1 LAN Network**"
    Internet address is 192.168.10.214/30
    MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec, 
    reliability 255/255, txload 1/255, rxload 64/255
    Encapsulation ARPA, loopback not set
    Keepalive set (10 sec)
    Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
    output flow-control is XON, input flow-control is XON
    ARP type: ARPA, ARP Timeout 04:00:00
    Last input 00:00:02, output 00:00:01, output hang never
    Last clearing of "show interface" counters never
    Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
    Queueing strategy: fifo
    Output queue: 0/40 (size/max)
    5 minute input rate 254280000 bits/sec, 496634 packets/sec
    5 minute output rate 1000 bits/sec, 0 packets/sec
    591814268 packets input, 1099031276 bytes, 0 no buffer
    Received 47685 broadcasts, 0 runts, 0 giants, 0 throttles
    0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
    0 watchdog, 47625 multicast, 0 pause input
    0 input packets with dribble condition detected
    432000 packets output, 56708628 bytes, 0 underruns

    No packet drops are seen on the Cisco router.

  • After enabling no-flow control on interface between Juniper-Cisco:
    ge-6/1/0 {
       gigether-options {
          no-flow-control;
       }

    No RED Drops are seen anymore

    Tail-dropped packets : 0 0 pps
    RED-dropped packets  : 0 0 pps 
  • Juniper will not stop any packets in spite of pause frames received from Cisco. Drops will be seen on Cisco Router.

    Now Cisco will drop packets on the incoming interface.

    CISCO-3845#sh int g0/0
    GigabitEthernet0/0 is up, line protocol is up 
    Hardware is BCM1125 Internal MAC, address is 0016.c8e6.9fb0 (bia 0016.c8e6.9fb0)
    Description: "**Connection to Node-1 LAN Network**"
    Internet address is 192.168.10.214/30
    MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec, 
    reliability 255/255, txload 1/255, rxload 43/255
    Encapsulation ARPA, loopback not set
    Keepalive set (10 sec)
    Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
    output flow-control is XON, input flow-control is XON
    ARP type: ARPA, ARP Timeout 04:00:00
    Last input 00:00:00, output 00:00:00, output hang never
    Last clearing of "show interface" counters never
    Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
    Queueing strategy: random early detection(RED)
    5 minute input rate 170522000 bits/sec, 333042 packets/sec
    5 minute output rate 2000 bits/sec, 0 packets/sec
    1042618197 packets input, 1176338647 bytes, 0 no buffer
    Received 52896 broadcasts, 1 runts, 0 giants, 0 throttles
    3142573 input errors, 1 CRC, 0 frame, 3142571 overrun, 0 ignored
    0 watchdog, 4473 multicast, 0 pause input

2. Use of mpls traffic-eng signalling advertise implicit-null on Cisco.

  • Before putting implicit null command on Cisco:
    PHP Router: 
    
    lab@ATT-M320-Re0# run show mpls lsp  
    Ingress LSP: 1 sessions
    To              From            State Rt ActivePath       P     LSPname
    11.11.11.11     1.1.1.1         Up     0                  *     to-cisco
    Total 1 displayed, Up 1, Down 0
    
    Transit LSP: 2 sessions
    To              From            State   Rt Style Labelin Labelout LSPname 
    9.9.9.9         11.11.11.11     Up       0  1 SE  164208        3 Tunnel-to-Juniper-T640
    11.11.11.11     9.9.9.9         Up       0  1 FF  164400        0 to-cisco3845
    Total 2 displayed, Up 2, Down           Default Label from Cisco is 0
    
  • Drop increasing on Juniper Router.
    Juniper@ATT-M320-Re0# run show interfaces queue ge-6/1/0    
    Physical interface: ge-6/1/0, Enabled, Physical link is Up
    Interface index: 202, SNMP ifIndex: 153
    Description: Connected to CISCO-3845 ge-0/0
    Forwarding classes: 16 supported, 4 in use
    Egress queues: 4 supported, 4 in use
    Queue: 0, Forwarding classes: best-effort 
      Queued:
        Packets              :               9162921                538987 pps
        Bytes                :             531449418             250089968 bps
      Transmitted:
        Packets              :               8462011                497400 pps
        Bytes                :             490796638             230793600 bps
        Tail-dropped packets :                118476                  7097 pps
    RED-dropped packets : 700441 42160 pps
    Low, non-TCP : 700441 42160 pps Low, TCP : 0 0 pps High, non-TCP : 0 0 pps High, TCP : 0 0 pps RED-dropped bytes : 44828224 21585920 bps Low, non-TCP : 44828224 21585920 bps Low, TCP : 0 0 bps High, non-TCP : 0 0 bps High, TCP : 0 0 bps
  • Mac pause frames increasing on Juniper
    lab@ATT-M320-Re0# run show interfaces ge-6/1/0 extensive    
    Physical interface: ge-6/1/0, Enabled, Physical link is Up
    <...>
     MAC statistics:                      Receive         Transmit
        Total octets                    7698137040     814273350791
        Total packets                    120074767      12090571383
        Unicast packets                      30165      12090535886
        Broadcast packets                       24               58
        Multicast packets                120044578            35439
        CRC/Align errors                         0                0
        FIFO errors                              0                0
        MAC control frames               120025971                0
        MAC pause frames                 120025971                0         
        Oversized frames                         0  
  • CPU utilization on Cisco Router boost 100%
     CISCO-3845(config)#do sh proc cpu his                          
     
       999999999999999999999999999999999999999999999999999999999999
        999999999999999999999999999999999999999999999999999999999999
    100 ************************************************************ 
     90 ************************************************************
     80 ************************************************************
     70 ************************************************************
     60 ************************************************************
     50 ************************************************************
     40 ************************************************************
     30 ************************************************************
     20 ************************************************************
     10 ************************************************************
       0....5....1....1....2....2....3....3....4....4....5....5....6 
  • Interface Stats on Cisco router. No drops will be seen here.
    CISCO-3845(config)#do sh int g0/0                                       
    GigabitEthernet0/0 is up, line protocol is up
    
      Hardware is BCM1125 Internal MAC, address is 0016.c8e6.9fb0 (bia 0016.c8e6.9fb0)
      Description: "**Connection to Node-1 LAN Network**"
      Internet address is 192.168.10.214/30
      MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec, 
         reliability 255/255, txload 1/255, rxload 64/255
      Encapsulation ARPA, loopback not set
      Keepalive set (10 sec)
      Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
      output flow-control is XON, input flow-control is XON
      ARP type: ARPA, ARP Timeout 04:00:00
      Last input 00:00:02, output 00:00:01, output hang never
      Last clearing of "show interface" counters never
      Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
      Queueing strategy: fifo
      Output queue: 0/40 (size/max)
      5 minute input rate 254280000 bits/sec, 496634 packets/sec
      5 minute output rate 1000 bits/sec, 0 packets/sec
         591814268 packets input, 1099031276 bytes, 0 no buffer
         Received 47685 broadcasts, 0 runts, 0 giants, 0 throttles
         0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
         0 watchdog, 47625 multicast, 0 pause input
         0 input packets with dribble condition detected
         432000 packets output, 56708628 bytes, 0 underruns
         3 output errors, 0 collisions, 3 interface resets
         0 unknown protocol drops
         0 unknown protocol drops
         0 babbles, 0 late collision, 0 deferred
         3 lost carrier, 0 no carrier, 0 pause output
         0 output buffer failures, 0 output buffers swapped out
  • After Configuring implicit null command on Cisco: Label Value changed to 3

    CISCO-3845(config)# mpls traffic-eng signalling advertise implicit-nul
    
    lab@ATT-M320-Re0# run show mpls lsp 
    Ingress LSP: 1 sessions To From State Rt ActivePath P LSPname 
    11.11.11.11 1.1.1.1 Up 0 * to-cisco 
    Total 1 displayed, Up 1, Down 0  
    Transit LSP: 2 sessions To From State Rt Style Labelin Labelout LSPname
    9.9.9.9         11.11.11.11     Up       0  1 SE  164208        3 Tunnel-to-Juniper-T640
    11.11.11.11     9.9.9.9         Up       0  1 FF  164416        3 to-cisco3845
    
  • RED Drop stopped increasing on Juniper.
    lab@ATT-M320-Re0# run show interfaces queue ge-6/1/0
    Physical interface: ge-6/1/0, Enabled, Physical link is Up
    Interface index: 202, SNMP ifIndex: 153
    Description: Connected to CISCO-3845 ge-0/0
    Forwarding classes: 16 supported, 4 in use
    Egress queues: 4 supported, 4 in use
    Queue: 0, Forwarding classes: best-effort
    Queued:
    Packets              :               2183817                546021 pps
    Bytes                :             117926118             235881072 bps
    Transmitted:
    Packets              :               2183818                546021 pps
    Bytes                :             117926172             235881072 bps
    Tail-dropped packets :                     0                     0 pps
    RED-dropped packets : 0 0 pps
    Low, non-TCP : 0 0 pps Low, TCP : 0 0 pps High, non-TCP : 0 0 pps High, TCP : 0 0 pps RED-dropped bytes : 0 0 bps Low, non-TCP : 0 0 bps Low, TCP : 0 0 bps High, non-TCP : 0 0 bps High, TCP : 0 0 bps lab@ATT-M320-Re0# run show interfaces ge-6/1/0 extensive Physical interface: ge-6/1/0, Enabled, Physical link is Up Interface index: 202, SNMP ifIndex: 153, Generation: 203 Description: **Connected to CISCO-3845 ge-0/0** Link-level type: Ethernet, MTU: 1514, Speed: 1000mbps, Loopback: Disabled, Source filtering: Disabled, Flow control: Enabled, Auto-negotiation: Enabled, Remote fault: Online Device flags : Present Running Interface flags: SNMP-Traps Internal: 0x4000 Link flags : None CoS queues : 8 supported, 4 maximum usable queues Hold-times : Up 0 ms, Down 0 ms Current address: 00:17:cb:98:1c:73, Hardware address: 00:17:cb:98:1c:73 Last flapped : 2009-08-12 06:57:10 UTC (1d 06:35 ago) Statistics last cleared: 2009-08-13 13:23:49 UTC (00:09:06 ago) Traffic statistics: Input bytes : 107133 616 bps Output bytes : 16126516424 235890000 bps Input packets: 157 0 pps Output packets: 298638911 546041 pps
  • CPU Utilization on Cisco decreased to 90%
    CISCO-3845(config)#do sh proc cpu his
    CISCO-3845   08:52:01 AM Thursday Aug 13 2009 UTC
    
    888888888888888888888888888888888888888888888888888888888888
    888888888888888888888888888888888999998888899999888888888888
    100                                                          
    90************************************************************
    80 ************************************************************
    70 ************************************************************
    60 ************************************************************
    50 ************************************************************
    40 ************************************************************
    30 ************************************************************
    20 ************************************************************
    10 ************************************************************
    
    CISCO-3845(config)#do sh int g0/0
    GigabitEthernet0/0 is up, line protocol is up
    Hardware is BCM1125 Internal MAC, address is 0016.c8e6.9fb0 (bia 0016.c8e6.9fb0)
    Description: Connection to Node-1 LAN Network
    Internet address is 192.168.10.214/30
    MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
    reliability 255/255, txload 1/255, rxload 66/255
    Encapsulation ARPA, loopback not set
    Keepalive set (10 sec)
    Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX
    output flow-control is XON, input flow-control is XON
    ARP type: ARPA, ARP Timeout 04:00:00
    Last input 00:00:02, output 00:00:00, output hang never
    Last clearing of "show interface" counters never
    Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
    Queueing strategy: fifo
    Output queue: 0/40 (size/max)
    5 minute input rate 258947000 bits/sec, 526305 packets/sec
    5 minute output rate 3000 bits/sec, 0 packets/sec
    786785715 packets input, 89016114 bytes, 0 no buffer
    Received 47872 broadcasts, 0 runts, 0 giants, 0 throttles
    0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
    0 watchdog, 47808 multicast, 0 pause input
    0 input packets with dribble condition detected
    432270 packets output, 56793795 bytes, 0 underruns
    3 output errors, 0 collisions, 3 interface resets
    0 unknown protocol drops
    0 unknown protocol drops
    0 babbles, 0 late collision, 0 deferred
    3 lost carrier, 0 no carrier, 0 pause output
    0 output buffer failures, 0 output buffers swapped out
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