Hi Oliver,
ping works fine here, see below.
Maybe UEFI Firmware v1.15 (vs. v1.13 you have been using) fixed it?
Note that your ifconfig output says "status: no carrier"...
Cheers,
Georg
Raspberry Pi 4 Model B
BCM2711 (ARM Cortex-A72)
UEFI Firmware v1.15
OpenBSD 6.7 (GENERIC.MP) #602: Thu May 7 13:45:48 MDT 2020
[email protected]:/usr/src/sys/arch/arm64/compile/GENERIC.MP
# ifconfig
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 32768
index 3 priority 0 llprio 3
groups: lo
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
inet 127.0.0.1 netmask 0xff000000
bse0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr dc:a6:32:b6:1d:bd
index 1 priority 0 llprio 3
media: Ethernet autoselect (1000baseT full-duplex)
status: active
enc0: flags=0<>
index 2 priority 0 llprio 3
groups: enc
status: active
vlan2: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr dc:a6:32:b6:1d:bd
index 4 priority 0 llprio 3
encap: vnetid 2 parent bse0 txprio packet rxprio outer
groups: vlan
media: Ethernet autoselect (1000baseT full-duplex)
status: active
inet 10.7.70.4 netmask 0xffffff00 broadcast 10.7.70.255
pflog0: flags=141<UP,RUNNING,PROMISC> mtu 33136
index 5 priority 0 llprio 3
groups: pflog
# ping 10.7.70.2
PING 10.7.70.2 (10.7.70.2): 56 data bytes
64 bytes from 10.7.70.2: icmp_seq=0 ttl=64 time=0.409 ms
64 bytes from 10.7.70.2: icmp_seq=1 ttl=64 time=0.160 ms
64 bytes from 10.7.70.2: icmp_seq=2 ttl=64 time=0.141 ms
64 bytes from 10.7.70.2: icmp_seq=3 ttl=64 time=0.138 ms
64 bytes from 10.7.70.2: icmp_seq=4 ttl=64 time=0.150 ms
64 bytes from 10.7.70.2: icmp_seq=5 ttl=64 time=0.138 ms
64 bytes from 10.7.70.2: icmp_seq=6 ttl=64 time=0.163 ms
64 bytes from 10.7.70.2: icmp_seq=7 ttl=64 time=0.138 ms