Other information that might help:
For some reason, the e1000e module was _not_ loaded. Tbh, I am not sure
why that was the case, unless e1000e is unrelated to this issue. FWIW, I
loaded it, just now.
# for i in /sys/class/net/bond0/bonding/*; do echo -n "$i : "; cat $i; done
/sys/class/net/bond0/bonding/active_slave :
/sys/class/net/bond0/bonding/ad_actor_key : 17
/sys/class/net/bond0/bonding/ad_aggregator : 1
/sys/class/net/bond0/bonding/ad_num_ports : 4
/sys/class/net/bond0/bonding/ad_partner_key : 2
/sys/class/net/bond0/bonding/ad_partner_mac : 00:d0:05:42:cc:00
/sys/class/net/bond0/bonding/ad_select : stable 0
/sys/class/net/bond0/bonding/arp_interval : 0
/sys/class/net/bond0/bonding/arp_ip_target :
/sys/class/net/bond0/bonding/arp_validate : none 0
/sys/class/net/bond0/bonding/downdelay : 0
/sys/class/net/bond0/bonding/fail_over_mac : none 0
/sys/class/net/bond0/bonding/lacp_rate : slow 0
/sys/class/net/bond0/bonding/miimon : 100
/sys/class/net/bond0/bonding/mii_status : up
/sys/class/net/bond0/bonding/mode : 802.3ad 4
/sys/class/net/bond0/bonding/num_grat_arp : 1
/sys/class/net/bond0/bonding/num_unsol_na : 1
/sys/class/net/bond0/bonding/primary :
/sys/class/net/bond0/bonding/slaves : eth0 eth1 eth2 eth3
/sys/class/net/bond0/bonding/updelay : 0
/sys/class/net/bond0/bonding/use_carrier : 1
/sys/class/net/bond0/bonding/xmit_hash_policy : layer2 0
# lsmod
Module Size Used by
xfs 432237 1
xt_tcpudp 2287 3
nf_conntrack_ipv4 9499 1
nf_defrag_ipv4 1139 1 nf_conntrack_ipv4
xt_state 1303 1
nf_conntrack 46185 2 nf_conntrack_ipv4,xt_state
iptable_filter 1410 1
ip_tables 13568 1 iptable_filter
x_tables 12754 3 xt_tcpudp,xt_state,ip_tables
sr_mod 12410 0
nfsd 256208 13
exportfs 3026 2 xfs,nfsd
nfs 235903 1
lockd 56807 2 nfsd,nfs
nfs_acl ...
