MTU issues



  • Hello,

    I'm running 2 TNSR in VMWARE and have set the vswitch to MTU9000.

    After this, I've created a network in this vswitch to connect the 2 TNSR hosts between them.
    For this interfaces in the hosts, I've also set the MTU to 9000.

    so all good, I can ping.

    [toor@labtnsr1 ~]$ ping 192.168.255.11 -s 8972 -M do
    PING 192.168.255.11 (192.168.255.11) 8972(9000) bytes of data.
    8980 bytes from 192.168.255.11: icmp_seq=1 ttl=64 time=0.227 ms
    8980 bytes from 192.168.255.11: icmp_seq=2 ttl=64 time=0.261 ms
    ^C
    --- 192.168.255.11 ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 57ms
    rtt min/avg/max/mdev = 0.227/0.244/0.261/0.017 ms
    [toor@labtnsr1 ~]$
    

    I've the TNSR dataplane network card also connected to this vswitch, but inside the TNSR, I can't ping over mtu 1512.

    labtnsr1 tnsr# dataplane ping 10.0.0.2 packet-size 1484
    PING 10.0.0.2 (10.0.0.2) 1484(1512) bytes of data.
    1492 bytes from 10.0.0.2: icmp_seq=1 ttl=64 time=0.259 ms
    1492 bytes from 10.0.0.2: icmp_seq=2 ttl=64 time=0.201 ms
    1492 bytes from 10.0.0.2: icmp_seq=3 ttl=64 time=0.248 ms
    ^C
    --- 10.0.0.2 ping statistics ---
    3 packets transmitted, 3 received, 0% packet loss, time 57ms
    rtt min/avg/max/mdev = 0.201/0.236/0.259/0.025 ms
    
    
    labtnsr1 tnsr# dataplane ping 10.0.0.2 packet-size 1485
    PING 10.0.0.2 (10.0.0.2) 1485(1513) bytes of data.
    ^C
    --- 10.0.0.2 ping statistics ---
    4 packets transmitted, 0 received, 100% packet loss, time 84ms
    
    labtnsr1 tnsr#
    

    The link MTU was correct to all interfaces, all are 9000, but IPv4 MTU was at 0.
    To test, I've also changed this MTU to 8000 (lower then the link MTU) and no good also.

    I've also put this command:

    labtnsr1 tnsr(config)# dataplane ethernet default-mtu 9000
    

    but nothing seems to work.

    Interfaces:

    labtnsr1 tnsr# show interface
    Interface: ipip0
        Admin status: up
        Link up, unknown duplex
        Link MTU: 9000 bytes
        IPv4 MTU: 8000 bytes
        IPv4 Route Table: ipv4-VRF:0
        IPv4 addresses:
            172.20.0.1/30
        IPv6 MTU: 0 bytes
        IPv6 Route Table: ipv6-VRF:0
        IPv6 addresses:
            fe80::7266:2fb0:9ce5:b003/64
        VLAN tag rewrite: disable
        counters:
          received: 19880 bytes, 165 packets, 0 errors
          transmitted: 23480 bytes, 168 packets, 0 errors
          protocols: 159 IPv4, 6 IPv6
          6 drops, 0 punts, 0 rx miss, 0 rx no buffer
    
    Interface: loop0
        Admin status: up
        Link up, unknown duplex
        Link MTU: 9000 bytes
        MAC address: de:ad:00:00:00:00
        IPv4 MTU: 0 bytes
        IPv4 Route Table: ipv4-VRF:0
        IPv4 addresses:
            172.21.0.1/32
        IPv6 MTU: 0 bytes
        IPv6 Route Table: ipv6-VRF:0
        IPv6 addresses:
            fe80::dcad:ff:fe00:0/64
        VLAN tag rewrite: disable
        counters:
          received: 0 bytes, 0 packets, 0 errors
          transmitted: 5852 bytes, 70 packets, 0 errors
          protocols: 0 IPv4, 35 IPv6
          26 drops, 0 punts, 0 rx miss, 0 rx no buffer
    
    Interface: trunk0
        Admin status: up
        Link up, link-speed 10 Gbps, full duplex
        Link MTU: 9000 bytes
        MAC address: 00:50:56:ba:ed:31
        IPv4 MTU: 8000 bytes
        IPv4 Route Table: ipv4-VRF:0
        IPv6 MTU: 0 bytes
        IPv6 Route Table: ipv6-VRF:0
        IPv6 addresses:
            fe80::250:56ff:feba:ed31/64
        VLAN tag rewrite: disable
        Rx-queues
            queue-id 0 : cpu-id 1
        counters:
          received: 55776 bytes, 300 packets, 0 errors
          transmitted: 94201 bytes, 275 packets, 5 errors
          protocols: 2 IPv4, 30 IPv6
          75 drops, 26 punts, 0 rx miss, 0 rx no buffer
    
    Interface: trunk0.50
        Description: VPLS
        Admin status: up
        Link up, link-speed 10 Gbps, full duplex
        Link MTU: 9000 bytes
        IPv4 MTU: 8500 bytes
        IPv4 Route Table: ipv4-VRF:0
        IPv4 addresses:
            10.0.0.1/28
        IPv6 MTU: 0 bytes
        IPv6 Route Table: ipv6-VRF:0
        IPv6 addresses:
            fe80::250:56ff:feba:ed31/64
        VLAN tag rewrite: disable
        detailed counters:
          received: 50084 bytes, 216 packets, 0 errors
          received unicast: 0 bytes, 0 packets
          received multicast: 0 bytes, 0 packets
          received broadcast: 0 bytes, 0 packets
          transmitted: 28050 bytes, 186 packets, 0 errors
          transmitted unicast: 0 bytes, 0 packets
          transmitted multicast: 0 bytes, 0 packets
          transmitted broadcast: 0 bytes, 0 packets
          protocols: 182 IPv4, 24 IPv6
          25 drops, 0 punts, 0 rx miss, 0 rx no buffer
    
    labtnsr1 tnsr#
    

    Dataplane shell shows 9000 also.

    labtnsr1 tnsr#  dataplane shell
    bash-4.4$ ifconfig
    lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 127.0.0.1  netmask 255.0.0.0
            inet6 ::1  prefixlen 128  scopeid 0x10<host>
            loop  txqueuelen 1000  (Local Loopback)
            RX packets 1  bytes 396 (396.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 1  bytes 396 (396.0 B)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    vpp1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
            inet6 fe80::250:56ff:feba:ed31  prefixlen 64  scopeid 0x20<link>
            ether 00:50:56:ba:ed:31  txqueuelen 1000  (Ethernet)
            RX packets 28  bytes 21918 (21.4 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 71  bytes 64603 (63.0 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    vpp3: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 9000
            inet 172.20.0.1  netmask 255.255.255.252  destination 172.20.0.1
            inet6 fe80::7266:2fb0:9ce5:b003  prefixlen 64  scopeid 0x20<link>
            unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 500  (UNSPEC)
            RX packets 192  bytes 13232 (12.9 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 207  bytes 13960 (13.6 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    vpp5: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
            inet 172.21.0.1  netmask 255.255.255.255  broadcast 0.0.0.0
            inet6 fe80::dcad:ff:fe00:0  prefixlen 64  scopeid 0x20<link>
            ether de:ad:00:00:00:00  txqueuelen 1000  (Ethernet)
            RX packets 0  bytes 0 (0.0 B)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 14  bytes 1076 (1.0 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    vpp7: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
            inet 10.0.0.1  netmask 255.255.255.240  broadcast 0.0.0.0
            inet6 fe80::250:56ff:feba:ed31  prefixlen 64  scopeid 0x20<link>
            ether 00:50:56:ba:ed:31  txqueuelen 1000  (Ethernet)
            RX packets 24  bytes 21246 (20.7 KiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 61  bytes 63619 (62.1 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    bash-4.4$
    
    

    Any idea how to go over this?

    My goal is to have iopsec tunnels allowing traffic with standard 1500 MTU, but I can't even get that ping over the trunk0.50 interface.

    Thanks.


  • LAYER 8 Netgate

    There is an issue being worked with jumbo frames and vmxnet3 interfaces on the dataplane in VMware.

    There is no workaround at the moment except using pass-through NICs or using E1000e for functionality testing purposes.



  • @Derelict
    Ok, thank you for the feedback.
    Will change the NIC's for now.


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