# mce1 connected to dpni9

```
### a disconnected interface
# ifconfig mce0 
mce0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=66ef07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,VLAN_HWFILTER,NV,VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,HWRXTSTMP,MEXTPG,VXLAN_HWCSUM,VXLAN_HWTSO>
        ether 6c:b3:11:79:5f:42
        media: Ethernet autoselect <full-duplex,rxpause,txpause>
        status: no carrier (Cable is unplugged.)
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
### a connected interface with dpni9 / xg1 at the other end
# ifconfig mce1
mce1: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
        options=66ef07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,VLAN_HWFILTER,NV,VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,HWRXTSTMP,MEXTPG,VXLAN_HWCSUM,VXLAN_HWTSO>
        ether 6c:b3:11:79:5f:43
        inet 10.0.0.11 netmask 0xffffff00 broadcast 10.0.0.255
        media: Ethernet 1000Base-CX-SGMII <full-duplex,rxpause,txpause>
        status: active
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
# ping -S 10.0.0.11 10.0.0.9
64 bytes from 10.0.0.9: icmp_seq=82 ttl=64 time=0.515 ms
64 bytes from 10.0.0.9: icmp_seq=83 ttl=64 time=0.205 ms
64 bytes from 10.0.0.9: icmp_seq=84 ttl=64 time=0.247 ms
```

## ten64 seeing the sweet sweet pings

```
root@r02:~ # tcpdump -vvveni dpni9
tcpdump: listening on dpni9, link-type EN10MB (Ethernet), snapshot length 262144 bytes
00:12:24.777847 6c:b3:11:79:5f:43 > 00:0a:fa:24:2f:7e, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 5505, offset 0, flags [none], proto ICMP (1), length 84)
    10.0.0.11 > 10.0.0.9: ICMP echo request, id 32704, seq 87, length 64
00:12:24.777902 00:0a:fa:24:2f:7e > 6c:b3:11:79:5f:43, ethertype IPv4 (0x0800), length 98: (tos 0x0, ttl 64, id 59547, offset 0, flags [none], proto ICMP (1), length 84)
    10.0.0.9 > 10.0.0.11: ICMP echo reply, id 32704, seq 87, length 64
00:12:25.135710 6c:b3:11:79:5f:43 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 63: (tos 0x0, ttl 64, id 4630, offset 0, flags [none], proto UDP (17), length 49)
    10.0.0.11.14048 > 10.0.0.255.32414: [udp sum ok] UDP, length 21
00:12:25.135726 6c:b3:11:79:5f:43 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 63: (tos 0x0, ttl 64, id 36047, offset 0, flags [none], proto UDP (17), length 49)
```


## swap dpni9 → dpni8

```
root@r02:~ # ifconfig dpni8
dpni8: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
        options=2b<RXCSUM,TXCSUM,VLAN_MTU,JUMBO_MTU>
        ether 00:0a:fa:24:2f:7d
        inet 10.0.0.8 netmask 0xffffff00 broadcast 10.0.0.255
        media: Ethernet 1000baseT
        status: active
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
```

```
root@wintermute /h/dch# ifconfig mce1
mce1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=66ef07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,VLAN_HWFILTER,NV,VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,HWRXTSTMP,MEXTPG,VXLAN_HWCSUM,VXLAN_HWTSO>
        ether 6c:b3:11:79:5f:43
        inet 10.0.0.11 netmask 0xffffff00 broadcast 10.0.0.255
        media: Ethernet autoselect <rxpause,txpause>               <------------ bad
        status: no carrier (No issue was observed)                 <------------ bad
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>

root@wintermute /h/dch# ifconfig mce1 media 1000Base-CX-SGMII mediaopt full-duplex
root@wintermute /h/dch# ifconfig mce1
mce1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=66ef07bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,VLAN_HWFILTER,NV,VLAN_HWTSO,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,HWRXTSTMP,MEXTPG,VXLAN_HWCSUM,VXLAN_HWTSO>
        ether 6c:b3:11:79:5f:43
        inet 10.0.0.11 netmask 0xffffff00 broadcast 10.0.0.255
        media: Ethernet autoselect
        status: no carrier (Negotiation failure)
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
```