# Localhost traffic puzzler after upgrade from 12.3 to 13.0



## astounding (May 6, 2022)

Check this out...

```
[root@host /conf]# ifconfig
em0: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=481249b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,LRO,WOL_MAGIC,VLAN_HWFILTER,NOMAP>
    ether 00:30:48:d5:c4:f1
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active
    nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
    options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
    inet6 ::1 prefixlen 128
    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
    inet 127.0.0.1 netmask 0xffffff00
    inet 127.0.0.2 netmask 0xffffffff
    inet 127.0.0.3 netmask 0xffffffff
    groups: lo
    nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
em0vlan10: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=4000403<RXCSUM,TXCSUM,LRO,NOMAP>
    ether 00:30:48:d5:c4:f1
    inet 10.0.0.100 netmask 0xffffff00 broadcast 10.0.0.255
    inet 10.0.0.101 netmask 0xffffffff broadcast 10.0.0.101
    inet 10.0.0.102 netmask 0xffffffff broadcast 10.0.0.102
    groups: vlan
    vlan: 10 vlanproto: 802.1q vlanpcp: 0 parent interface: em0
    media: Ethernet autoselect (1000baseT <full-duplex>)
    status: active
    nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
[root@host /conf]# ping -S 127.0.0.1 10.0.0.100
PING 10.0.0.100 (10.0.0.100) from 127.0.0.1: 56 data bytes
64 bytes from 10.0.0.100: icmp_seq=0 ttl=64 time=0.065 ms
64 bytes from 10.0.0.100: icmp_seq=1 ttl=64 time=0.044 ms
64 bytes from 10.0.0.100: icmp_seq=2 ttl=64 time=0.059 ms
^C
--- 10.0.0.100 ping statistics ---
3 packets transmitted, 3 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 0.044/0.056/0.065/0.009 ms
[root@host /conf]# ping -S 127.0.0.1 10.0.0.101
PING 10.0.0.101 (10.0.0.101) from 127.0.0.1: 56 data bytes
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
ping: sendto: Can't assign requested address
^C
--- 10.0.0.101 ping statistics ---
3 packets transmitted, 0 packets received, 100.0% packet loss
[root@host /conf]# ipfw list
00090 allow ip from any to any
65535 deny ip from any to any
```
Do you see that?  This exact same ping WORKED under FreeBSD 12.3 just fine, zero config. changes, but now is failing.  There are no other FIBs, just the usual default one.  And the primary ethernet interface talks on a tagged VLAN.  Its alias IP addresses now cannot talk to any loopback IP or any of the loopback alias IPs.

This is a PUZZLER!

Suggestions where to look?  There is a firewall, ipfw, that permits all traffic.

IDEAS?  Have you seen this before?

I discovered this after a jail (using an alias IP on the 10.0.0.x network) suddenly could no longer talk to a process in a different jail (a web server running on one of the localhost 127.0.0.x alias IPs) after an upgrade using freebsd-update from 12.3 to 13.0.

HELP!

Thanks for any pointers!

Aaron Gifford


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## SirDice (May 6, 2022)

```
em0vlan10: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
    options=4000403<RXCSUM,TXCSUM,LRO,NOMAP>
    ether 00:30:48:d5:c4:f1
    inet 10.0.0.100 netmask 0xffffff00 broadcast 10.0.0.255
    inet 10.0.0.101 netmask 0xffffffff broadcast 10.0.0.101
    inet 10.0.0.102 netmask 0xffffffff broadcast 10.0.0.102
```
This is not a vlan(4) interface. Proper vlan(4) interfaces look like this:

```
lagg0.10: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 9000
        description: vm-vlan-public-lagg0.10
        options=4000000<NOMAP>
        ether 00:25:90:f1:58:39
        groups: vlan vm-vlan viid-bdfd6@
        vlan: 10 vlanproto: 802.1q vlanpcp: 0 parent interface: lagg0
        media: Ethernet autoselect
        status: active
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
```
Note the `vlan:` information. Your em0vlan10 is missing the VLAN ID and parent interface.


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## astounding (May 6, 2022)

You can name VLAN interfaces anything you want, nearly, with the right config.   VLAN 10 is functioning normally passing traffic normally.

The ifconfig output was apparently truncated when I edited my message.  Oops.  Here's the missing bit that confused you:


> groups: vlan
> vlan: 10 vlanproto: 802.1q vlanpcp: 0 parent interface: em0
> media: Ethernet autoselect (1000baseT <full-duplex>)
> status: active
> nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>


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## jb_fvwm2 (May 6, 2022)

FWIW i've multiple wlan0 hardware that worked, iirc on v12 and before which silently fail on v13 and current. Could be local to my installs though.


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