adding TCP Kill

TCP-Kill.md

@@ -0,0 +1,30 @@
+## Killing a stalled TCP connection
+
+Requires: kernel >= 4.9 with `CONFIG_INET_DIAG_DESTROY`
+
+Scenario: subprocess `rclone` has encountered trouble and started to stall out, running at a severely decreased rate of speed
+
+Task: pause rclone, kill the in-progress TCP connection, resume rclone which will trigger it to (re)create a new, working TCP connection (app dependent)
+
+### Steps
+
+Find the process and it's TCP stalled connection:
+
+```
+$ ps axo pid,comm | grep [r]clone
+  6874 rclone
+
+$ ss -ntp | grep [r]clone | awk '{print $5, $6}'
+74.120.9.121:443 users:(("rclone",pid=6874,fd=9))
+```
+
+Pause the process, kill the connection (as root), resume the process:
+
+```
+$ kill -STOP 6874
+
+$ sudo ss -K dst 74.120.8.14 dport 443
+
+$ kill -CONT 6874
+```
+

_Sidebar.md

@@ -54,6 +54,7 @@
 - [[Smem Datamash]]
 - [[Split Disk]]
 - [[systemd PID1]]
+- [[TCP Kill]]
 - [[Thunderbird LDAP AD]]
 - [[uBlock Filters]]
 - [[udev Hide Partitions]]