Thank you, Rich. Interesting that you get an IPv6 address without explicitly asking for one.
In output of lsmod I also see "ipv6":
$ lsmod
Module Size Used by Tainted: G
ipv6 270336 24 [permanent]
ccm 16384 9
cpufreq_userspace 12288 0
cpufreq_powersave 12288 0
cpufreq_conservative 12288 0
i915 1003520 8
snd_hda_codec_hdmi 32768 1
ath9k 73728 0
mac80211 262144 1 ath9k
snd_hda_codec_conexant 16384 1
snd_hda_codec_generic 45056 1 snd_hda_codec_conexant
snd_hda_intel 24576 0
drm_kms_helper 94208 1 i915
snd_hda_codec 61440 4 snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_intel
ath9k_common 12288 1 ath9k
ath9k_hw 372736 2 ath9k,ath9k_common
snd_hda_core 36864 5 snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_intel,snd_hda_codec
drm 253952 7 i915,drm_kms_helper
snd_hwdep 12288 1 snd_hda_codec
snd_pcm 57344 4 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_core
ath 28672 3 ath9k,ath9k_common,ath9k_hw
snd_timer 20480 1 snd_pcm
snd 45056 8 snd_hda_codec_hdmi,snd_hda_codec_conexant,snd_hda_codec_generic,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm,snd_timer
i2c_i801 16384 0
cfg80211 192512 4 ath9k,mac80211,ath9k_common,ath
intel_agp 16384 0
soundcore 12288 1 snd
iosf_mbi 12288 1 i915
intel_gtt 16384 2 i915,intel_agp
agpgart 28672 3 drm,intel_agp,intel_gtt
i2c_algo_bit 12288 1 i915
battery 16384 0
squashfs 28672 212
zstd_decompress 65536 1 squashfs
xxhash 12288 1 zstd_decompress
video 32768 1 i915
backlight 12288 2 i915,video
ac 12288 0
sdhci_pci 24576 0
cqhci 16384 1 sdhci_pci
sdhci 32768 1 sdhci_pci
lpc_ich 20480 0
e1000e 126976 0
mmc_core 73728 3 sdhci_pci,cqhci,sdhci
r592 16384 0
acpi_cpufreq 12288 1
memstick 12288 1 r592
xhci_pci 12288 0
xhci_hcd 98304 1 xhci_pci
loop 20480 424