ss --info returns information about tcp connections. It produces a line simliar to the following (some fields removed for formatting)
tcp ESTAB 0 0 192.168.1.177:60236 54.70.141.88:https
cubic wscale:7,7 rto:204 rtt:0.918/0.419 reordering:59
What exactly does the reordering number mean in this example?
From TCP Variables:
The tcp_reordering variable tells the kernel how much a TCP packet may be reordered in a stream without assuming that the packet was lost somewhere on the way.
tcp_reordering may be changed via net.ipv4.tcp_reordering variable of sysctl. By default this value is 3.
If you change net.ipv4.tcp_reordering variable, then ss --info will print all connections with values which are differs from 3. Fragment of iproute2 source:
. . .
if (s->reordering != 3)
printf(" reordering:%d", s->reordering);
. . .
