Description

The customer was performing upgrade on MX204 router and they noticed the BGP peering inside the Virtual Switch of the MX204 taking approximately 30 minutes to come up.

Symptoms

The MAC address for the BGP neighbors had been learnt when the customer collected the outputs:

 

root@D1HMDC-AG02> show arp no-resolve

 

MAC Address    Address     Interface        Flags

24:fc:4e:bd:44:72 10.42.7.4    xe-0/1/7.10       none

24:fc:4e:bc:72:63 10.42.7.6    et-0/0/0.10       none

00:1a:f0:a1:f0:4e 10.42.7.19   xe-0/1/6.10       none

24:fc:4e:bd:44:72 10.42.8.130   xe-0/1/7.20       none

b4:0c:25:e7:80:10 10.48.226.1   ae0.2280         none

00:10:db:ff:40:02 10.48.240.17  ae0.2298         none

00:10:db:ff:60:03 10.48.240.33  irb.2297 [.local..5]   permanent remote

24:fc:4e:bc:7a:74 10.48.240.34  irb.2297 [.local..5]   permanent remote

00:10:db:ff:10:00 10.52.5.254   fxp0.0          none

00:10:db:ff:10:02 10.52.8.1    irb.2100 [.local..7]   permanent remote

24:fc:4e:bc:7a:74 10.52.8.2    irb.2100 [.local..7]   permanent remote

fe:54:00:2b:8a:6f 128.0.0.16   em3.0          none

fe:54:00:2b:8a:6f 128.0.0.101   em3.0          none

fe:54:00:7e:88:66 192.168.1.2   em2.32768        none

Total entries: 14

 

<<<<<<<< the traffic should be sent out of interface xe-0/1/1.2297 via L3 irb.2297.

 

routing-instances {

  VS-2297 {

    instance-type virtual-switch;

    protocols {

      evpn {

        default-gateway no-gateway-community;

        extended-vlan-list 2297;

      }

    }

    bridge-domains {

      BD-2297 {

        domain-type bridge;

        vlan-id 2297;

        routing-interface irb.2297;

      }

    }

    interface xe-0/1/1.2297;

    route-distinguisher 65240:222297;

    vrf-target target:65240:222297;

  }

}

 

<<<<<< Based on the xe-0/1/1 interface, there is no dropped packets, nor errors.

 

The issue is NO received packets!

 

Physical interface: xe-0/1/1, Enabled, Physical link is Up

 Interface index: 155, SNMP ifIndex: 560, Generation: 158

 

 Input errors:

  Errors: 0, Drops: 0, Framing errors: 0, Runts: 0, Policed discards: 0, L3 incompletes: 0, L2 channel errors: 0, L2 mismatch timeouts: 0, FIFO errors: 0, Resource errors: 0

 Output errors:

  Carrier transitions: 1, Errors: 0, Drops: 0, Collisions: 0, Aged packets: 0, FIFO errors: 0, HS link CRC errors: 0, MTU errors: 0, Resource errors: 0

 Egress queues: 8 supported, 4 in use

 Queue counters:    Queued packets Transmitted packets   Dropped packets

  0               126         126          0

  1                0          0          0

  2                0          0          0

  3                79          79          0

 

 

 MAC statistics:           Receive     Transmit

  Total octets               0      37434

  Total packets              0       205

  Unicast packets             0        5

  Broadcast packets            0       126

  Multicast packets            0        74

  CRC/Align errors             0        0

  FIFO errors               0        0

  MAC control frames            0        0

  MAC pause frames             0        0

  Oversized frames             0

  Jabber frames              0

  Fragment frames             0

  VLAN tagged frames            0

  Code violations             0

  Total errors               0        0

 Filter statistics:

  Input packet count            0

  Input packet rejects           0

  Input DA rejects             0

  Input SA rejects             0

  Output packet count                   205

  Output packet pad count                  0

  Output packet error count                 0

  CAM destination filters: 0, CAM source filters: 0

 

 

Before upgrade ---- Looked fine

========================

 MAC statistics:                     Receive        Transmit

   Total octets                1472097702500    590724080604

   Total packets                  1039420137       521444818

   Unicast packets                1039418492       520578860

   Broadcast packets                    1645           16533

   Multicast packets                       0          849425

   CRC/Align errors                        0               0

   FIFO errors                             0               0

   MAC control frames                      0               0

   MAC pause frames                        0               0

   Oversized frames                        0

   Jabber frames                           0

   Fragment frames                         0

   VLAN tagged frames             1039420137

   Code violations                         0

Total errors                            0               0

Solution

The issue was related to underlayer L2 problem, for example, some L2 issues caused the packets dropping in the middle. JTAC can only see the output/transmit packets/Octets, not see any receive/incoming packets/octets in interface xe-0/1/1 in the RSI file after upgrade. This is abnormal and some thing wrong at L2/L1 layer.

Modification History

2024-07-17 : Article Created